Endangered Spec UPDATE December f 996 School of Natural Resources and Environment Vol. 13 No. 12 THE UNIVERSITY OF MIICI-IIGAN

Special Issue: Conservation and Management of the Southern Sea Otter " was reintroduced into Yellowstone National Park. Photograph by Waiter 0. SUaglltz. U.S. FWS She courageously defended the reauthorization of the Endangered Species Act, blocked efforts to open the Arctic National Wildlife Refuge to oil exploration, and battled Congress over funding cutbacks aimed at crippling environmental programs. And, most notably, she guided the Service in adopting an ecosystem approach to conservation.

It was Mollie Beattie's vision that inspired the design of this Special Issue of the Endangered Species UPDATE. We began with the premise that the conservation of the threatened sea otter population off the California coast will rely on the ability to establish effective partnerships, to manage the threats to this population, and to resolve the conflicts over the uses of marine resources. In partnership with the Monterey Bay Aquarium, we then assembled a list of authors, experts in their field of sea otter biology or on the issues surrounding the species' conservation, and invited them to contribute to the publication. Each author was encouraged to identify key issues surrounding the conservation of the sea otter and to present a list of research and management recommendationswithin their area of expertise. We hope that the resulting publication will serve as the first step in developing strong conservation-oriented partnerships, and we dedicate it to the memory of Mollie Beattie.

Mollie H. Beattie served as Director of the U.S. Fish and Wildlife Service from September 10,1993, until she was forced to resign due to ill health on June 5,1996. A few weeks later she died after a year- long battle with cancer. In recognition of her accomplishments, President Clinton signed an act designating eight million acres of the Alaska Arctic National Wildlife Refuge as the Mollie Beattie Wilderness Area. "It ensures that future generations will recall the lasting contributions Mollie made to conserving our Nation's priceless natural heritage," said President Clinton. Table of Contents

I. BIOLOGYAND STATUSOF THE SOUTHERNSEAOTTER 1. Introduction to the Special Issue: Why Southern Sea Otters?...... 4 John F. Watson and Terry L. Root 2. Sea Otter Systematics and Conservation: Which are Critical Subspecies?...... 6 C. Gregory Anderson, John L. Gittleman, Klaus-Peter Koepfli, and Robert K. Wayne 3. Comparative Demography of Sea Otter Populations...... I1 James A. Estes, Daniel F. Doak, James R. Bodkin, Ron J. Jameson, Daniel Monson, Jon Watt, and M. Tim Tinker 4. Monitoring the Status of the Wild Sea Otter Population: Field Studies and Techniques...... 14 James L. Bodkin and Brenda E. Ballachey 5. Organochlorine Contaminants in Sea Otters: The Sea Otter as a Bio-indicator ...... 20 Walter M. Jarman, Corinne E. Bacon, James A. Estes, May Simon, and Ross J. Norstrom 6. The Risk of Disease and Threats to the Wild Population ...... 23 Nancy J. Thomas and Rebecca A. Cole

11. RECOVERYUNDER THE ENDANGEREDSPECIES ACT 7. Overview of the Legislative Mandates and the Agencies Responsible for Implementation of Southern Sea Otter Protection Under the Endangered Species Act ...... 28 Jamie Rappaport Clark 8. Evaluating Attempts to Reintroduce Sea Otters Along the California Coastline...... 31 Carl Benz 9. The Second Southern Sea Otter Recovery Plan...... 36 Carl Benz 10. Assessing the Threat of Oil Spills to Southern Sea Otters...... 38 Michael L. Bonnell, R. Glenn Ford, and Allan J. Brody 11. Does 'Sanctuary' Mean Secure?...... 43 Rachel T. Saunders 12. The Role of Friends of the Sea Otter in Resource Protection...... 47 Ellen Faurot-Daniels and Donald C. Baur

111. THEROLE OF REHABILITATIONAND CAPTIVEMANAGEMENT IN SEA OTTER CONSERVATION 13. The Role of Rehabilitation in Sea Otter Conservation Efforts ...... 50 Thomas D. Williams and Terrie M. Williams 14. Oiled Wildlife Care for Sea Otters and Other Marine Animals in California: A Government, University, Private Sector, Non-Profit Cooperative...... 53 David A. Jessup, Jonna A. K. Mazet, and Jack Ames 15. Safeguarding Diversity: Challenges in Developing a Genome Resource Bank for the California Sea Otter...... 57 Julie A. Long, Shawn E. Larson, and Samuel K. Wasser 16. Sea Otters in Captivity: The Need for Coordinated Management as a Conservation Strategy...... 61 E. Jean Brennan and John Houck 17. A ComplexChromosome Rearrangementin the Karyotype of a Wild-Caught Male Sea Otter ...... 68 Deborah A. Duffield, Jan Chamberlin-Lea, and James E. Antrim

IV. RECOVERYUNDER THE MARINEMAMMAL PROTECTION An AND BEYOND 18. The Law Governing Sea Otter Conservation...... 73 Donald C. Baur, Allison M. Meade, and Lisa M. Rotterman 19. Estimating the Historical Abundance of Sea Otters in California ...... 79 Douglas P. DeMaster, Catherine Marzin, and Ron J. Jameson 20. The State of California's Role in the Conservation of Sea Otters and Other Aquatic Resources...... 82 Fred Wendell 21. Saving the Sea Otter Population in California: Contemporary Problems and Future Pitfalls...... 85 Glenn R. VanBlaricom

This SpeciulZssue of the Endangered Species UPDATE has been developed in apartnership with the Monterey Bay Aquarium. The purpose ofthe non-pro@ Monterey Bay Aquarium is to stimulate interest, increase knowledge undpromote stewardship of Monterey Bay and the MONTEREY BAY world's ocean environment through exhibit, education, and research progmms. AQUARIUM Prodtcction of this issue was made possible in patt by suppoItfiom the Monteny l3ayAquh.m

Vol. 13 No. 12 1996 Endangeredspecles UPDATE 3 Introduction to the Special Issue: Why Southern Sea Otters? - John F. Watson and Terry L. Root

Many casualenvironmentalists,wild- includes other species such as weasels, California most births occur between late life enthusiasts, and animal lovers view minks, and skunks. Two subspecies of February and April, although births do the sea otter (Enhydra lutris) as the pre- sea otters have been commonly occur throughout the year. Otters live cise type of animal that the Endangered recognized, the Asian (Enhydra lutris between 12-20 years, and chief causes of Species Act (ESA) was designed to pro- gracilis) and Alaskan (Enhydra lutris mortality have not been determined (see tect: a highly charismatic, cute mammal lutris) sea otters, and some biologists Thomas and Cole, this issue). that is easy to observe. Additionally, consider the southern sea otter (Enhydra many conservation advocates view the lutris nereis) to be a third subspecies (see Sea otter protection sea otter as a flagship species around Anderson et al., this issue). Sea otters have been classified as which to rally support for protection of the Alaskan and Asian sea otters are threatened under the ESA, depleted under marine environment, for the ESA, and for widely distributed across theNorth Pacific the MMPA, and as a "fully protected other regulations that lhtenvironmen- from Washington State to the KurilIslands mammal" under Californiastate law. Each tally harmful or risky practices. Those and Kamchatka Peninsula in Russia, with of these levels of protection is si&cant designing andimplementing seaotter con- a total population estimated at over for different reasons. Protection under servation management plans must address 100,000 (U. S. Fish and Wildlife Service California state law, which preceded the complex biological needs of a species, 1996). Southern sea otters live along a federal protection under the MMPA or while planning and implementing com- stretch of less than 400 kilometers (250 ESA, involves balancing the needs of plex regulations that seek to balance the miles) of the California coast around otter conservation witheconomicinterests, interests of the otter, of people advocating Monterey Bay. This population, of especially fisheries along the California different levels of preservation, and of roughly 2,400 individuals, is believed to coast. Protection under the ESA is of people who see their jobs and industries be increasing at approximately 5 to 7 special interest at this time because the threatened. percent per year (U. S. Fish and Wildlife ESA is up for reauthorization in Congress We chose to focus this Special Issue Service 1996). A translocated population and has been the subject of contentious of the Endangered Species UPDATE on of roughly 20 individuals is located at San debate. Protection under the MMPA is the southern sea otter for a number of Nicolas Island, which is located about currently superseded by the listing under reasons. A large amount of information 110 kilometers (70 miles) west of Los the ESA. The MMPA listing will become exists on southern sea otters, especially Angeles (see Benz, Attempts to relevant only after the southern sea otters' compared to other marine organisms, Reintroduce, this issue). population and range expands to the point making the sea otter a good species for Sea otters are found along rocky, that it is delisted under ESA (see Baur; which to examine management concerns. sandy, and mixed shores, but are most VanBlaticom, this issue). The southern sea otter population, while common along rocky shores and prefer For a number of reasons the southern currently listedunderthe ESA, is growing. habitat with kelp (see DeMaster et al., this sea otter is an excellent species for Therefore, we can expect that the issue). They generally remain close to exploring policy issues under each of population willbe delisted under the ESA, shore in areas where the water depth is 20 these laws and jurisdictions. The sea otter making other laws such as the Marine meters (65 feet) or less, which facilitates is well studied and relatively well Mammal Protection Act (MMPA) and their foraging along the ocean floor. Sea understood, especially compared to other state laws applicable to future sea otter otters eat avariety of marine invertebrates, marine species. Its population history, of management. Finally, as with many other including such items as crabs, mussels, being hunted to near extinction for its fur species, conservation of sea otter clams, abalones, and sea stars. They also and then rediscovered in California, is populations necessitates managing will catch and eat fish and marine birds on well known and documented. conflicts between species protection and occasion (Riedman and Estes 1990). Consequently, we have alot ofinformation industry. Our hope in putting together this Otters are believed to have a significant necessary to help determine whether the issue is to provide a broad base of the best effect on their marine environment by southern sea otter is a separate subspecies knowledge we have on southern seaotters reducing prey populations that feed on (see Anderson et al., this issue). This to help facilitate future conservation kelp (U.S. Fish and Wildlife Service 19%). question of subspecies is representative of management. Their effect on local fisheries has been a similar debates under the ESA, which contentious issue in California (see currently protects threatened subspecies The southern sea otter Wendell, this issue). of animals that have unthreatened Sea otters are one of twelve species Female sea otters typically give birth populations elsewhere (for example, the of otters worldwide and belong to one of to a single pup each year. Females are bald eagle, rare and protected in much of four groups of marine mammals. They believed to reach sexual maturity after the contiguous United Statesbut common are members of the mustelid family, which three years, and males after five years. In in parts of Alaska). Additionally, issues

4 Endangered Species UPDATE Vo1.13 No. 12 1996 of habitat protection have been especially include the efficacy of rehabilitation species troublesome in the ESA debate, and our efforts, and the role of captive otters in the UPDATE knowledge of southern sea otters larger sea otter conservation plans. provides valuable insights into The final section is based on an A forum for information exchange on endangered species issues protecting marine habitats. assumption that the otter will continue its December I996 Vol. 13 No. 12 Sea otters are charismatic and a recovery and eventually be delisted under favored target for protection, yet their the ESA, making the Mh4PA the relevant John Watson ...... Er protection has created large conflicts with statute for future otter conservation plans. Katherine Irvine ...... Associate Editor David Bidwell ...... Editorial Assistant two major industries, oil transportation This section provides background on the Gideon Lachman...... Web Page Coordinator and fishing. How we deal with conflicts WA,examines the critical issue under Nicole Shun...... Subscription Coordinator between conservation and industry is, of MMPA of estimatingthecarrying capacity John Brosnan...... Subscription Coordinator course, an ongoing debate, and is the of the habitat off the California coast, and Terry Root ...... Faculty Advisor Special Issue Contributing Editor subject of several papers in thisissue (e.g., looks at the concept of zonal management E. Jean Brennan Bornell; Saunders; Wendell). as a possible basis for management in the Monterey Bay Aquarium Finally, the otter is a good subject for future. The concluding article looks to the study because its population is recovering future of otter conservation efforts. Adviso~Board Richard Block and we can expect it to be delisted under Indianapolis Zoo ESA in the forseeable future. The need Conclusion Susan Haig for management of the population will not Conservationplanning must bebased National Biological Service, end, however, with the delisting under on the best science available, and our goal Oregon State University Nonnun Myers ESA. Issues of conflict will remain in in putting together this issue is to compile International Consultant in managing the population as it grows and a broad base of the best knowledge we Environment and Development protection shifts to MMPA and then have on sea otters today. Undoubtedly Patrick O'Brien possibly to California state law. Indeed, there are readers who will disagree with Chevron Ecological Services Hal Salwasser preparing for the future management of some of the points made, who would have U.S. Forest Service, the otter as an unlisted species is critical in preferred to see some issues left out or Boone and Crockett Club order to be able to successfully manage others highlighted. These questions and the population throughout the future. possible disagreements reflect the reality Inslru~iionsfor Authors: The Endangered Species UPDATE welcomes articles, editorial of managing for the conservation of a comments, and announcements related to Special Issue format complex species: there are no easy species protection. For ftuther information The Sea Otter Special Issue is divided answers, and the problems will remain contact the editor. into four sections. The first focuses on the contentiouseven as conservationplanning Subscription InJormation: The Endangered biology and status of the otter. Articles in and implementation moves forward. We Species UPDATE is published six times per this section look at the distribution of the hope, however, that in publishing this year by the School of Natural Resources and otter through its entire range; how the issue we provide a strong basis for future Environment at The University of Michigan. California population relates to other thought on sea otter conservation, and Annualsub~criptionrateis$23,and$18for students and senior citizens (add $5 for postage populations;methods for monitoring these also that we provide a model for looking outside the US). Send check or money order populations; the otter as an indicator of at other species that must be managed for (payable to The University of Michigan) to: pollutants in the marine community; and conservation. Endangered Species UPDATE risks of diseasethat wild populations face. School of Natural Resources and Environment The second section focuses on the Literature Cited The University of Michigan recovery of the sea otter under the ESA. Riedman,M.L. and J.A. Estes. 1990. The seaotter Ann Arbor, MI 48109-1 115 The first article in this section provides (Enhydra lum's):behavior, ecology, and natural (313) 763-3243 history. U.S. Department of the Interior, Fish email: [email protected] background on the ESA, with subsequent and Wildlife Service. Biological Report 90(14). articles examining Recovery Plans and Washington, D.C. 126 pp. Front and back cover: Sea otten (Enhydra attempts to implement a translocation as U.S. Fish and Wildlife Service. 1996. Southern luh). Photogmphs by Jeff Foott. For recommended by the first Recovery Plan; sea otter recovery plan, 1996 draft. Ventura, information on ordering prints see the California. 41 pp. the threat of oil spills to theotter's recovery; advertisement on page 27. the history of the National Marine The views expressed may not necessarily Sanctuary that encompasses much of the reflect those of the U.S. Fish and Wildlife otter's habitat; and the role of non- John Watson is the Editor of the Endangered Service or The University of Michigan. Species UPDATE. He is completing a Master's governmental organizations in the listing Degree in Natural Resource Policy at the School and protection of the otter. Production of this issue was made possible by of Natural Resources and Environment (SNRE) suppo~tfrom the Monterey Bay A@um, Treatment and rehabilitation of sea and an MBA at the University of Michigan Chevron Gnpration, Boone and Crocketi Business School. Teny L. Root is the Faculty otters have played a prominent role in Club, and Walt Disney World Company. Advisor for the UPDATE, and is Associate conservation, and the third section looks Professor of Resource Ecology at the SNRE at at these efforts. Questions addressed the University of Michigan. MONTEREY BAY AQUARIUM

Vol. 13 No. 12 1996 Endangered Species UPDATE 5 Sea Otter Systematics and Conservation: Which are Critical Subspecies?

C. Gregory Anderson, John L. Gittleman, Klaus-Peter Koepfli, and Robert K. Wayne

The sea otter (Enhydra sp.) is a uted (see Figure 1). Historical records 1762, after thousands of pelts were charismatic carnivore. As an aquatic, of distribution are reasonably reliable, exported from Bering Island by crustacean feeder possessing four inci- as Enhydra was known to the indig- commercial hunters, there were too few sors in the lower jaw, having webbed enous peoples who hunted them, and sea otters in the area to justify feet, and spending most of its life on its trade in sea otter pelts to the Spanish commercial expenses in hunting them. back, this is not your typical carnivore! began in California at least by and prob- This pattern was repeated throughout Although all otters have adaptations for ably prior to 1733 (Ogden 1941). The the range of the sea otter, exterminating living in an aquatic environment, sea historical range of the sea otter extended population after population around the otters have carried this approach to an across the Pacific rim in a wide arc from Pacific rim from Kamchatka to Alaska, extreme and are unique in many re- Mono Hermoso in Baja California to BritishColumbia, Washington,Oregon, spects. Indeed, in tracing the history of the island of Hokkaido in northern Ja- California, and B aja California. sea otter taxonomy some early authori- pan (Ogden 1941; Barabash-Nikiforov Estimates for the total number of sea ties confused the many aquatic adapta- 1947). Population estimates for this otters killed from 1740 to 1911 range tions of the sea otter with its phyloge- historical range vary from between from 500,000 (Kenyon 1969) to well netic heritage. As a result, the sea otter 100,000-150,000 (Kenyon 1969) to over 800,000 (Lensink 1960). The result was even misplaced with the pinnipeds, 300,000 (Johnson 1982). of such unregulated hunting was a which include seals and sea lions, rather According to Barabash-Nikiforov patchwork of roughly 11 - 13 isolated than with the mustelids, which include (1947),intensive hunting of the seaotter populations from what was once a river otters, weasels, and badgers. Nev- in the northern part of its range began continuous distribution (Kenyon 1969). ertheless, species designation andmuch almost immediately upon the return of It is estimated that only about 1,000 of the phylogenetic history of the sea Steller from the Bering Expedition individuals survived the onslaught of otter have been remarkably consistent ( 174 1- 1742), which collected over 700 commercial hunting (Kenyon 1969), and accurate (see Table 1). The main pelts. This expedition provided one of between 1 and 2 percent of the original systematic difficultiesrestwith whether the first detailed descriptions of the sea estimated population. subspecific units are meaningful evolu- otter from Bering Island, but ironically In California, estimates of histori- tionarily and how to manage these units also led to its extirpation there. By cal population numbers range from 16- froma conservation stand- point. In this paper, we pame Author Comments review the historv of sea ~utramarina teller (1751) Binomial but ore-Linnaean and therefore considered to be otter systematics,summa- unacceptable according to the International Commission of rize morphological and Zoological Nomenclature (ICZN) molecular studies of sub- Mustela lurris Linnaeus (1 758) Partially based on Steller's account (1751), Musrela was used species, comment on the for all members of the Mustelidae recognized at that time. 'ystematics phoca lutris Pallas (1 8 11) An attempt to ally Enhydra with the Pinnipeds. have for conservation ef- forts, and provide sug- Pusa orienlaliis Oken (1816) An attempt to give Enhydra its own generic appellation but Oken's names are not available according to the ICZN (and has gestions for future areas been synonymized. with Phoca). of study. Enhydra nlarina Fleming (1822) Oldest available valid Genus name.

ranges and Latax lutris Gloger (1827) Renaming of Pusa Oken, which was preoccupied. extirpations ~ik~many carni- Enydris marina Lichtenstein (1827) Emmendation of Ellhydra. vores, the history of sea Enchydris Lesson ( 1842) Emmendation of Enhydra. otter distribution is one of aninitialcontiguousrange Enhydris lutris Lesson ( 1842) Emmendation of Enhydra.

by periodic ex- Enhydra lutris Gray (1843) First use of current name combination. tirpations, leaving present-day population Surra marina Elliot ( 1874) Junior synonym of Enhydra. ranges patchily distrib- Table 1. History of the taxonomy of the sea otter, Enhydra lutris.

6 Endangered Species UPDATE Vo1. 13 No. 12 1996 PACIFIC OCEAN Point Sur, California

Present Distributm (1964) Remnant Colonies (191 1) - Surviving Translocated Populations SC

Figure 1. Present distribution of the sea otter.

20,000 (Ralls et al. 1983; see DeMaster Subspecific status different from the Aleutian Island form et al., this issue). Commercial hunting Subspecies are defined as a geo- and so designated the Northern Ameri- began in 1784 and ended in 1840 when graphical or ecological population can form as E.Z. lutris, the Kuril- it became unprofitable due to the low within a species which differs from any Kamchatkan race as E.Z. gracilis, and number of available sea otters (Ogden other such population within the same the Southern Californian group as E.Z. 1941). The population was thought to species. The difficulty arises in what nereis. Barabash-Nikiforovbasedthese be extinct by the turn of the century, but we mean by "differs." Variation within findings on measurements from 5 speci- a small group of between 32-50 were a species often differs among individu- mens from the Aleutian Islands and observed in 1914 (Bryant 1915). Sub- als, varieties and subspecies; the prob- Alaska, 3 specimens from the Com- sequent rediscoveries of sea otters in lem lies in determining how much of mander Islands, 7 from Mednyi Island, California elicited much excitement. this variation represents a legitimate 5 fromthe southern tip of the Kamchatka When a rancher and his wife found a subspecies. Subspecific delineations Peninsula, and 1 from Bering Island. small population off the coast of Big involve a continuous process of refine- No specimens were available from ei- Sur in 1938 (Bolin 1938), one marine ment with a subspecies proposed, then ther the Kuril Islands or California. The biologist remarked that reporting dino- reanalyzed and refined, until relative separation of E.1. gracilis was based saurs would not have caused more sur- stability is reached. Recently emphasis primarily on pelage differences de- prise (Wolkomir 1995)! has been placed on taxonomically iden- scribed from pelt scraps (Barabash- Under protection of the Interna- tifying subspecies by concordant char- Nikiforov 1947) and the description of tional Fur Trade Treaty of 1911, sea acters which are consistent with explicit this form was later refuted by Stroganov otter populations around the Pacific phylogenetic partitioning (Avise and (1962) because it is a composite of other began to recover, slowly at first and Ball 1990; O'Brien and Mayr 1991). subspecies (but see below). mainly in areas with little human distur- The following is a review of how the The subspecific taxonomy of the bance. Today, it is estimated that sea above subspecific delineations for southern sea otter (E.1. nereis) was not otters inhabit most of their historic range Enhydra have been refined over the contested until Scheffer and Wilke west of Prince William Sound (Riedrnan years and provide a consistent phyloge- (1950) reexamined the specimen used and Estes 1988, 1990; Estes 1990), but netic picture. by both Merriam (1904) and Grinnell et populations have not yet fully recov- al. (1937) as well as new material from ered in Southeast Alaska and British Morphological data western (1146) and southeastern (1x2) Columbia and are very limited south of Barabash-Nikiforov (1947) was the Alaska, Washington (n=l), Oregon British Columbia. first to suggest that the Commander (n=2), and California (n=5, including Island subspecies was not sufficiently the type-specimen). They concluded

Vol. 13 No. 12 1996 Endangerwl Species UPDATE 7 ecies name Author Common name Status

E. 1. lutris (Linnaeus 1758) Asian sea otter CITES Appendix 2

E. 1. kenyoni (Wilson, 1991) Alaskan sea otter CITES Appendix 2

E. 1. nereis (Merriam 1904) California sea otter CITES Appendix I U.S. ESA Threatened Table 2. Commonly recognized subspecies of sea otter.

that several of Merriam's characters were cies are needed to clarify the systemat- with the sea otter, particularly in flawed and there was insufficient evi- ics at the subspecific level. evaluating the subspecific question dence to support the existence of a south- What new analyses would improve (Scribner et al., in press). em subspecies of sea otter. Despite our understanding? As stated, most Lidicker and McCollum (198 1, these assertions, most authors were not phylogenies across species have been cited in Riedman and Estes 1990, and convinced because of small sample sizes morphological, with major emphasis on Scribner et al., in press) used allozymes and therefore continued to recognize the cranial and dental characters. Consis- to determine levels of heterozygosity southern subspecies (e.g., Murie 1959). tency among studies is hampered by and genetic differentiation between the In 1969,Kenyoncriticallyreviewed selection of different characters, sub- Californian and Alaskan populations. the southern subspecies question, spe- jective evaluations of characters, varia- Their findings indicated that five of 30 cifically in regard to Scheffer and tion in phylogenetic methods, and non- loci were variable and no alleles were Wilke's (1950) analysis. Kenyon sum- representation of some taxa (see Table 1). site specific; they hypothesized that the marized his position as follows: "...it is We are now correcting some of these absence of rare alleles in the California not possible, without further study, to problems (Anderson and Gittleman, in population was due to population bottle- distinguish racially distinct populations preparation) by analyzing across all neck effects, although this is not com- whichmight exist" (Kenyon 1969, p. 5). lutrines a broader suite of morphologi- pletely accepted. Later, Kenyon (1982) reiterated the con- cal and other characters (e.g., behav- Rotterman (1992) also used clusion of Roest: "...all sea otters from ioral and life history traits) than has allozymes to assess genetic variability the Pacific coast of North America rep- been previously used. In addition, as between three Alaskan populations and resent a single clinally varying popula- many complications of phylogenetic the California population. Of 41 loci tion, Enhydra lutris lutris" (Roest 1979, study undoubtedly rest with conver- examined, only three were variable, and p. 14). The precise study called for by gence due to the effects of aquatic liv- only two of these were sufficiently vari- Kenyon was performed by Wilson et al. ing, molecular analyses will play a criti- able to be informative. Genetic dis- (1991), with one ironic result being an cal role in better understanding system- tances for these populations were also accepted subspecies designation bear- atic relationships. small (0.001-0.006), revealing a high ing Kenyon's name, Enhydra lutris degree of genetic similarity (Nei 1978) kenyoni. This study examined 236 speci- Molecular data that would not confirm subspecific sta- mens from the former Soviet Union, 84 Molecular analyses will serve as an tus for the California population. An from northwestern North America and independent test of the results obtained intriguing result from the genetic dis- Alaska, and 48 specimens from Califor- from morphological analyses. Most tance analysis was that the California nia (total n=368), using a sequential molecular studies to date have only population showed a higher genetic af- discriminant function analysis. They examined higher level relationships finity to several of the Alaskan popula- found clear support for the recognition among carnivore families (Wayne et al. tions than among the Alaskan popula- of three subspecies of sea otter, with the 1989; Vrana et al. 1994; Ledje and tions themselves. greatest distinction existing between the Arnason 1996); few have dealt with Recent analyses of mitochondria1 two extreme populations in the USSR relationships within the Mustelidae (but DNA (mtDNA) employing restriction and California, and mandibular length see Masuda and Yoshida 1994). fragment-length polymorphisms generally being the best morphological However, a project examining the (RFLPs) assessed relationships among character for subspecific recognition. phylogenetic relationships among otter populations in Prince William Sound, Currently there are three recognized species using DNA sequences of the the Kuril Islands, and central California subspecies of Enhydra lutris (Reeves et mitochondria1DNA cytochrome b gene (Sanchez 1992). The California popu- al. 1992; Wozencraft 1993), as shown is currently underway (Koepfli and lation was most divergent from the in Table 2. Wayne, in preparation). Prince William Sound population, fol- In summary, morphological analy- Molecular techniquesare quite useful lowed by the Kuril Island and Prince ses have consistently supported subspe- for delineating systematic relationships William Sound populations, and lastly cies designations. However, further among populations and subspecies(Avise the Kuril Island and California popula- phylogenetic studies of these subspe- 1994). Much molecular work is ongoing tions, revealing total genetic divergences

8 Endangered Species UPDATE Vol. 13 No. 12 1996 of 0.0008-0.0060. Sanchez concluded Conclusion and (4) Although allozymes have been that the mtDNA haplotype distribution recommendations used previously (see review in Scribner generally supported the morphological Molecular studies consistently et al., in press), additional nuclearmark- classification of Wilson et al. (1991), support differentiation among ers with higher variability need to be although there was also indication of populations along subspecificlines. The employed to assess concordance with recent common ancestry, high gene flow California subspecies (E.1. nereis) mitochondria1 DNA results. Koeplfi and reduced effective population sizes. appears to have monophyletic and Wayne are currently conducting To date, analyses of mitochondria1DNA haplotypes of mtDNA, which do not such a study using hypervariable nuclear (mtDNA) have only approximated di- overlap with other populations; in microsatellite markers. vergences among otters and other contrast, E.l. lutris and E.1. kenyoni Without question, bad taxonomy is mustelids using linear fragments from have frequencies of haplotypes which detrimentalto conservation efforts. An different parts of the mtDNA molecule are similar to some extent. Four increasing number of studies show that without mapping restriction sites problems should receive future endangered and threatened species must (Cronin et al. 1996); therefore, caution molecular work. be rigorously defined by explicit phylo- must be taken because single-locus phy- (1) The California haplotypes, genetic units (Avise and Ball 1990; logenies may not be accurate. though monophyletic, are not unequivo- O'Brien and Mayr 1991). Present data Most recently, Cronin et al. (1996) cal and therefore phylogenetic analysis indicate validity of named subspecies used RFLPs of several large segments should be performed alongside other for the sea otter and therefore current of mtDNA, amplified using the poly- genetic and morphological studies protection measures should remain in merase chain reaction (PCR) technique, (Cronin et al. 1996). place to ensure the survival of threat- to investigate genetic differentiation (2) Genetic sequence analysis us- enedpopulations. (E.1. nereisis listed as within and among subspecies. Results ing the mitochondrial DNA control re- threatened under the Endangered Spe- indicate that only E.1. nereis has mono- gion and nuclear microsatellites should cies Act and under CITES Appendix 1, phyletic mtDNA, not found in either be used todistinguish populations within all other subspecies are listed under populations of E. 1. lutris or E. I. kenyoni. subspecies which may be important for CITES Appendix 2; see Baur et al.; Cronin et al. (1996) propose an explana- idenwing populations that may be man- Clark, this issue). Further systematic tion that there was pre-exploitation diver- aged as independent units (currently be- work is needed, however, to bring into gence between the following four groups: ing carried out by Koepfli and Wayne). line subspecific recognition with regard California, Prince William Sound, (3) Much of the studies using to phylogenetic units. First, phyloge- Kodiak-Adak-Amchitka-Attu-Medney mtDNA (e.g., Cronin et al. 1996; netic analyses of different phenotypic islands, and Kuril island populations. In Sanchez 1992; Koepfli and Wayne, in characters and molecular gene markers examining these results it appears that preparation) have shared samples. An should resolve the history of natural these divergent populations correspond independent analysis is needed to as- population distinctions. Second, phy- to the four most frequently proposed sub- sess whether some concordance among logeneticpopulation clusters should then species (E.1. nereis, E.1. kenyoni, E.1. lutris, molecular results is affected by sk- be identified in relation to and E.1. gracilis, respectively). pling biases. phylogeographic boundaries. Conser- vation efforts involving captive man- agement and breeding programs as well as reintroduction plans must demand such results from systematics.

Literature Cited Avise, J.C. 1994. Molecular markers, natural history, and evolution. Chapman and Hall, New York, New York. 5 11 pp. Avise, J.C., and R.M. Ball Jr. 1990. Principles of genealogical concordance in species concepts and biological taxonomy. Oxford Surveys in Evolutionary Biology 7:45-67. Barabash-Nikiforov,1.1. 1947. Kalan. Pages 1- 174 in Soviet Ministrov RSFSR. Glavnoe upravlenie po zapovednikam. [The sea otter. Translated from Russian by A. Birron and Z.S. Cole for the National Science Foundation by the Israel Program for Scientific Translations, Jerusalem, Israel. 1962. 227 pp.]. Bolin, R.L. 1938. Reappearance of the southern sea otter along the California coast. Journal of Mammalogy 19:301-303.

Vol. 13 No. 12 1996 Endangered Species UPDATE 9 Bryant, H.C. 1915. Sea otter near Point Sur. sea otters in Alaska. Journal of Mammalogy Academy of Sciences 75267-270. California Fish and Game 1:134-135. 41:172-182. Roest, A.I. 1979. A reevaluation of sea otter Cheney, L.C. 1995. An assessment of genetic Lesson, R.P. 1827. Manuel de Mammalogie. taxonomy. Page 14 in Abstracts of the Sea Otter variation within and between sea otter (Enhydra Roret, Paris, France. 441 pp. Workshop, August 23-25,1979, Santa Barbara, lum's) populations off Alaska and California. Lesson, R.P. 1842. Nouveau Tableau du R&gne California. M.S. thesis, San Jose State University, Moss Animal. MammiRres. Paris, France. Rotterman, L.M. 1992. Patterns of genetic Landing, California. 49 pp. Lidicker, W.Z. andF.C. McCollum. 1981. Genetic variability in sea otters after severe population Cronin, M. A., J. Bodkin, B. Ballachey, J. Estes, and differentiation of sea otter populations. Fourth subdivision and reduction. Ph.D. dissertation, J.C.Patton. 1996.Mitochondrial-DNAvariation Biennial Conference on the Biology of Marine University of Minnesota, Minneapolis, and populations of sea otters (Enhydra lutris). Mammals, December 14-18, San Francisco, Minnesota. 227 pp. Journal of Mammalogy 77:546-557. California. Sanchez, M.S. 1992. Differentiation andvariability Davis, J.A. 1978. A classification of the otters. Linnaeus, C. 1758. Systema naturae per regna tria of mitochondrial DNAin three sea otter,Enhydra Pages 14-33 in N. DuPlaix, editor. Otters: naturae, secundum classes, ordines, genera, lutris, populations. M.S. thesis, University of proceedings of the fmt working meeting of the species, cum characteribus, differentiis, California, Santa CM, California. 101 pp. Otter Specialist Group. Paramibo, Surinam, synonymis, locis. 10th edition Laurentii Salvii, Scheffer, V.B. and F. Wilke. 1950. Validity of the March, 1977. IUCN, Morges, Switzerland. Upsala 1:l-824. subspecies Enhydra luhis nereis, the southern Davis, J.D. and WZLidicker. 1975. Thetaxonomic Masuda, R. andM.C. Yoshida 1994. A molecular sea otter. Journal of the Washington Academy status of the southern sea otter. Proceedings of phylogeny of theFamily Mustelidae (Mammalia, of Science 75269-272. the California Academy of Sciences, Fourth Carnivora), based on comparison of Scribner, K.T., J. Bodkin, B. Ballachey, S.R. Fain, Series 40:429-437. mitochondrial cytochrome b nucleotide M.A. Cronin, and M. Sanchez. In press. Elliot, H.W. 1874. The sea otter and its hunting. sequences. Zoological Science 11:605-612. Population genetic studies of the sea otter Pages 54-62 in A report upon the condition of Merriam,C.H. 1904. Anew seaotterfromsouthern (Enhydra luhis): a review and interpretation of affairs in the Territory of Alaska. HouseExecutive California. ProceedingsoftheBiological Society available data. U.S. Department of Commerce, Document Number 83, 44th Congress, 1st of Washington 17:159- 160. National Oceanic and Atmospheric session, Washington, D.C. 277 pp. Murie, O.J. 1959. Fauna of the Aleutian islands Administration Technical Report. Estes, J.A. 1990. Action plan for sea otters. Pages and Alaska peninsula. North American Fauna Steller, G.W. 1751. De Bestiis Marinis. Novi 22-28 inP. Foster-Turley, S. Macdonald, and C. 61: 1-406. Commentarii Academiae ScientianunImperialis Mason, editors. Otters: an action plan for their Nei, M. 1978. Estimationof average heterozygosity Petropolitanae 2389-398, pls. 14-16. conservation. IUCNBSC Publication, Kelvyn and genetic distance from a small number of Stroganov, S.U. 1962. Zveri Sibiri: khishchnye. Press, Broadview, Illinois. 126 pp. individuals. Genetics 89:583-590. Akademiya Nauk SSSR. Sibirskoe Otdelenie. Fleming. 1822. The Philosophy of Zoology. O'Brien, S.J. and E. Mayr. 1991. Bureaucratic Biologicheskii Institut, Moskow. [Carnivorous Archibald Constable, Edinburgh, Scotland. mischief: recognizing endangered species and mammals of Siberia. Translated from Russian 2187-188. subspecies. Science 251: 1187-1188. by A. Biron, published for the Smithsonian Gittleman, J.L. and S.L. Pimm. 1991. Crying wolf Ogden, A. 1941. The Califomia sea otter trade Institution and the National Science Foundation in North America. Nature 351:524-525 1784-1848. University of California Press, by the Israel Program for ScientificTranslations, Gloger, C.W.L. and J.L.C. Gravenhont. 1827. Berkeley, California. 25 1 pp. Jerusalem, Israel. 1%9. 522 pp.]. Bemerkungen iiber ein Paar schlesische Oken, L. 1816. Lehrbuch der Natugeschichte. van Zyll de Jong, C.G. 1972. A systematic review Saugethierarten. Nova acta Academiae Zoologic. August Schmidt und Comp., Jena of the nearctic andneotropicalriver otters. Royal Caesareae Leopoldino-Carolinae Germanicae 3:l-1270. Ontario Museum 80:l-104. Naturae Curiosorium 13479-512. Pallas, P.S. 18 11. Zoographia Rooso-Asiatica. St. Vrana, P.B., M.C. Miliiovitch, J.R. Powell, and Gray, J.E. 1843. List of the specimens of Mamrnalia Petersburg 1:l-100. W.C. Wheeler. 1994. Higher level relationships in the collection of the British Museum. British Ralls, K., J. Ballou, and R.L. Brownell. 1983. of the Arctoid Carnivora based on sequence data Museum(Natural History) Publications,London, Genetic diversity in California sea otters: and "total evidence."Moleculat Phylogenetics United Kingdom. 2 16 pp. theoretical considerations and management and Evolution 3:47-58. Grinnell, J., J.S. Dixon,and J.M. Linsdale. 1937. implications. Biological Conservation Wayne, R.K., R.E. Benveniste, D.N. Janczewski, Fur-bearing mammals of California. 25:209-232. and S.J. O'Brien. 1989. Molecular and University of California Press, Berkeley, Reeves, R. R., B. S. Stewart, and S. Leatherwood. biochemical evolution of the Carnivora. Pages California. 375 pp. 1992. 'Ihe Sierra Club Handbook of Seals and 465-494 in J. L. Gittleman, editor. Carnivore Hanis, C.J. 1%8. Otters: a study of the recent Sirenians. Sierra Club Books, San Francisco, behavior, ecology and evolution. C~mell Lutrinae. Weidenfield and Nicolson, London, California. 359 pp. University Press, New York, New York 620pp. United Kingdom. 397 pp. Riedman, M.L. and J.A. Estes. 1988. A review of Wilson, D.E., M.A. Bogan, R.L. Brownell, A.M. Johnson, A.M. 1982. The sea otter, Enhydra lutris. the history, distribution,and foraging ecology of Burdin, and M.K. Marninov. 1991. Geographic Mammals in the seas: small cetaceans, seals, sea otters. Pages 4-21 in G.R. VanBlaricom and variation in sea otters, Enhydra lutris. Journal of sireneans, and otters. Food and Agriculture J.A. Estes, editors. The community ecology of Mammalogy 7222-36. Organization of the United Nations. Fisheries sea otters. Springer-Verlag Publishing, New Wolkomir, R. 1995. The frilgile recovery of Series 5(4):525-531. York, New York. 237 pp. California sea otters. National Geographic, Kenyon, K.W. 1969. The sea otter in the eastern Riedman, M.L. and J.A. Estes. 1990. The sea otter 181:42-61. Pacific Ocean. North American Fauna, Number (Enhydra lufris): behavior, ecology, and natural Wozencraft, W.C. 1993. Order Carnivora. Pages 68.352 pp. history. U.S. Department of the Interior, Fish 279-348 in D. E. Wilson and D. M. Reeder, Kenyon, K.W. 1982. Seaotter. Pages 704-710 and Wildlife Service. Biological Report 90(14). editors. Mammal species of the world: A in J.A. Chapman and G.A. Feldhamme, Washington, D.C. 126 pp. taxonomic and geographic reference. editors. Wild mammals of North America: Roest, A.I. 1971. Asystematic study oftheseaotter SmithsonianInstitutionPress,Washington, D.C. biology, management, and economics. Johns (Enhydra luiris). Pages 133-135 in Proceedings 1207 pp. Hopkins University Press, Baltimore, of the Eighth hmalConference on the Biology Maryland. 1147 pp. of Sonar and Diving Mammals. Menlo Park, Greg Anderson and John Gittleman are with Ledje, D. and U. Arnason. 1996. Phylogenetic C&fomia. the Department of Ecology and Evolutionary analyses of complete cytochrome b genes of the Roest, A.I. 1973. Subspecies of the sea otter, Biology,The University of Tennessee, Order Carnivora with particular emphasis on the (Enhydra lufris). Contributions in Science, Los Knoxville, TN 37996-1610. Klaus-Peter Caniformia. Journal of Molecular Evolution Angeles County Museum 140(252):1- 17. Koepfli and Robert Wayne are with the 42135-144. Roest, A.I. 1976. Systematicsand the status of sea Department of Biology, The University of Lensink, C.J. 1960. Status and distribution of otter Enhydra lutris. Bulletin of the California California, Los Angeles, CA, 90024-1606.

10 Endangered Species UPDATE Comparative Demography of Sea Otter Populations James A. Estes, Daniel F. Doak, James R. Bodkin, Ron J. Jameson, Daniel Monson, Jon Watt, and M. Tim Tinker Population trends are poorly docu- sea otter's range. Nonetheless, varying rates. AU 4 populations increased at 17- mented and demographic information is conditions and purposes of workin differ- 20% per year, which is near the sea otter's typically lacking for many carnivorous ent areas have inevitably influenced the theoretical maximum rate of increase, r- mammals. The sea otter (Enhydra lutris) comparability of available data. (sensu Cole 1954), based on known or has a well known history of decline and estimated values of key life history pa- recovery, and while many other species Trends in abundance rameters (Estes 1990). Furthermore,these have declined as precipitously, few have The earliest comprehensive reports growth trajectories have shown no indica- recovered so spectacularly. Generally of status and trends in sea otter popula- tion of density compensation,even though speaking, northern populations (remnants tions were written by Barabash-Nikiforov the population in southeast Alaska con- within the range of E. 1. lutris and E. I. (1947)andlensink(l960). Karl Kenyon's tained greater than 1500 individuals at the kenyoni) have recovered at high rates (1969) monograph summarized informa- timeof thelast survey. However, themost while recovery of the southern sea otter tion through the mid- 1960sand reports by recent information from Washington (R. (E. 1. nereis), which is listed as legally Rotterman and Simon-Jackson (1988), Jameson, unpublished) indicates that the threatened under the Endangered Species Riedrnan and Estes (1990), and Estes population growth rate there has declined Act (ESA), has progressed more slowly. (1991) provide the most recent updates. somewhat in the past few years. Our purpose is to contrast trends in abun- By the early 1900s sea otters had Although there has been less consis- dance and demographic patterns between been hunted to near extinctionthroughout tency in the census techniques used to southern (California) and northern (Wash- their range (Lensink 1960). When prohi- survey California sea otters, this popula- ington, British Columbia, Alaska, and bition against further take was enacted in tion clearly has grown more slowly than Asia) sea otter populations. Specifically, 191 1, a dozen known colonies remained, the northem populations. Except for the we provide (1) a brief review of the main none of which are thought to have con- mid-1970s to the early 1980s, when the findings to date; (2) a summary of ongo- tained more than several hundred indi- California sea otter declined (Estes 1990) ing and planned studies; and (3) recom- viduals (Kenyon 1969). These colonies in apparent response to incidental mortal- mendations for future research. A more recovered at varying rates in the ensuing ity in a coastal set net fishery (Wendell et detailed account of these and other issues decades, although not in unison. The sea al. 1985), the rate of increase has consis- concerning the conservation and manage- otter population at Amchitka Island in the tently been about 5% per year. This ment of sea otters is provided in the U.S. western Aleutian archipelago was one of comparatively low rate of increase, Fish and Wildlife Service's Recovery Plan the first to recover, apparently reaching coupled with its small size, limited range, for the California SeaOtter (U.S. Fish and equilibrium numbers by the late 1930s or and concern over possible catastrophic Wildlife Service 1996). early 1940s. Inother areasrecoverylagged losses from oil spills, led the U.S. Fish and behind by as much as a half century. Wildlife Service to list the California sea Summary of past research Sea otters were hunted to extinction otter population as threatened under the Demographic information on sea ot- in several isolated areas of the Aleutian ESA in 1977. ters comes from several sources. Popula- archipelago and along the west coast of tion monitoring programs have been con- North America between eastern Prince Demographic patterns ducted mostly by state and federal agen- William Sound and central California. The strikingly different growth rates cies. Information on reproduction and They were reestablished in the late 1960s between sea otter populations in Califor- mortality comes from work conducted by and early 1970s to southeast Alaska, Brit- nia and more northern regions is attribut- scientists from state and federal agencies, ish Columbia, and Washington via relo- able to different demographic schedules. academia, and the private sector. Al- cations (Jameson et al. 1982), and in the That is, the populations differ in some though there have been several long-term mid-1960s a small colony naturally re- aspect of their age-specific probabilities monitoring programs, most information colonized Attu Island, western-most of of reproduction, survival,or some combi- on population trends, and much of what is the Aleutians (Jones 1965). The subse- nation thereof. Differences in mortality known about reproduction and mortality, quent growth of these colonies has been are thought to be the main factor explain- comes fromthepost hoc assembly of data documented through repeated surveys. ing divergent rates of population growth, that were collected for other purposes. In These data are informative because (1) as explained below. some cases recognition of patterns is con- founding population sizes are known in Most females conceive andgive birth founded by the different methods used in all cases; (2) each area was surveyed for the first time at age 3, and since the existing research. More recently, there using consistent methods; and (3) the lengths of gestation and post-parturn de- has been a concerted effort to apply con- populations are sufficiently isolated that pendency are each about 6 months, fe- sistent techniques in studies of reproduc- movement among populations is unlikely males that successfully wean their pups tion and mortality in different parts of the to have affected their population growth reproduce on roughly an annual cycle

Vol. 13 No. 12 1996 Endangered Species UPDATE 11 (Jameson and Johnson 1993; Riedman et Ongoing and planned research demography and behavior of individuals al. 1994). Females usually come into Population monitoring of sea otters within these populations. Most of this estrous within a few days of separating in California and Washington is part of information has not been published and from their pup. Therefore, when pups are the U.S. Department of the Interior's re- some of it was obtained by people no lost prematurely, the reproductive cycle is search program, and is expected to con- longer working with sea otters. We rec- shortened. Although most pregnancies tinue indefinitely. Elsewhere, population ommend that all of the relevant demo- probably are canied to term, many post- surveys probably will be done opportu- graphic data be identified, assembled into partum losses occur shortly after birth. nistically, or as the need arises. a comprehensive data base, and analyzed Despite this, age of first reproduction and A large-scale comparative study of and synthesized. At the very least, this the age-specific probability of females sea otter demography and behavior was will clarify what information is available giving birth appear to be largely invariant initiated in the early 1990s. This project is and what more is needed. among populations, irrespective of being conducted as a series of 2 to 3 year (2) Population modelling. A rigor- whether they are increasing, at or near studies of populations that are either small ous analytical effort is needed to help field equilibrium, or in decline (Jameson and and growing rapidly or large and at or near researchers focus their efforts on the most Johnson 1993;Bodkin et al. 1993;Monson equilibrium density. Similar methods, revealing populations, age and sexclasses, and DeGange 1995; Monson et al., un- centered on information obtained from a and demographidbehavioral parameters. published manuscript; Tinker and Estes, sample of individuals equipped with sur- Properly done, population modelling can unpublished data). gically implanted radio transmitters, are serve as a reality check for preconcep- In contrast to reproductive rates, age- used in each study. Information on diet, tions and interpretations that have be- specific mortality schedules vary consid- activity-time budgets, distribution and come accepted without benefit of rigor- erably among seaotterpopulations.Maxi- movements, reproductive success, and ous analysis. For instance, we have ar- mum longevity of wild sea otters is about mortality is being gathered. In addition, gued that elevated mortality, as opposed 20 years (Bodkin, unpublished data). surveys of pre-determined coastal seg- to depressed reproduction, is responsible Beach-cast carcasses are rarely found in ments are conducted at monthly intervals for the regulation of sea otter populations areas where populations are growing rap to obtain samples of beach-cast carcasses, as they approach equilibrium density. idly, and most of those that are recovered and to determine trends in abundance and While this argument is supported by the are aged (Kenyon 1969). This observa- reproduction. There is ongoing or re- available data and may be correct, recent tion, and the analysis of population growth cently completed field research at work on another carnivore species, the potential based on life history data indi- Amchitka and Adak islands (populations cheetah, suggests that a more careful look cate that very low mortality between birth near equilibrium density), and Shemya is needed. In the case of the cheetah, cub and senescence is the rule in populations Island and Washington State (growing mortality is highly variable and this varia- that are increasing at rates near r- (Estes populations). A similar study is planned tion has been assumed to be responsible 1990). In contrast, the age-specific mor- for California where the data will be added for the growth or decline of local popula- tality schedule of resource-limited popu- to those obtained in the 1980s by Siniff tions (Can, and Laurenson 1994). How- lations, such as those at Amchitka Island and Ralls (1988). The ultimate goals of ever, iterated simulationsof cheetahpopu- or western Prince William Sound, fea- this program are to relate population sta- lation trends using the available life his- tures an increased probability of mortality tus to demographic and behavioral pat- tory data show that observed levels of cub among dependent and recently weaned terns, and in particular to better under- mortality have relatively little effect on juveniles. Therefore, the age-structure of stand the status and factors limiting growth population growth or decline, and that beach-cast carcasses from resource-lirn- of the California population. adult mortality is the likely causal vari- ited populations is bimodal, with peaks at able (Crooks et al., in review). The case of the very young and old age classes. Mor- Conclusion and the cheetah is relevant to sea otters be- tality rates of individuals between about 3 recommendations cause (a) we have also assumed that mor- and 8 years are very low, regardless of The above-described activities will tality of young animals is the major driv- population status. A third pattern, in form an empirical backbone for the long- ing variable in population trends, and (b) which probability of mortality is rela- term conservation and management of seaotters, like cheetahs, come into estrous tively high for all post-weaning ages, pro- sea otters. Continued population moni- immediately after becoming separated duces a carcass age structure similar to toring is probably the most fundamental fivm their young. Thus, it may be that that of the living population. This pattern need, although information on elevatedpupmoitality,especiallythat which was seen following the Exxon VaMez oil demography and behavior is also neces- occurs shortly post-partum, pmcbces an el- spill (Bodkin et al. 1993) and is also sary if there is to be any hope of understand- evated rate of fecundity, in turn buffering the typical of the California population (Pletz ing the observed trends. Three additional population against decline. Prelnnu~~~ et al. 1988). The reason for this mortality areas of research could enhance this goal. analyses of data collected fmm a declining pattern is stillpoorly understood, although (I) Synthesize available data. A population at Adak Island, Alaska suggest there appear to be a wide range of possible great deal of information already has been that variation in adult modity rates may be causes. gathered on the abundance and trends of a critical regulabng factor in sea otter popu- sea otter populations, and on the lations (Tinker andEstes,unpublished data).

12 Endangered Species UPDATE Vol. 13 No. 12 1996 (3) Develop a better understanding like sea otters. Similarly, very long time Monographs 6575-100. of linkages between sea otter population scales (e.g., millennia) are too long to Estes, J.A. andG.R. VanBlaricom. 1985. Seaotters and shellfisheries. Pages 187-235 in J.R. biology and community- and ecosystem- worry about because it is virtually impos- Beddington,R.J.H. Beverton, andD.M. Lavigne, levelprocesses. Ultimately, mostpopula- sible to forecast environmental, social, editors.MarineMammals and Fisheries. George tion trends are driven by some aspect of and political changes over these time Allen and Unwin, London, United Kingdom. the habitat. Food, predators, space, and scales. We should probably be concemed Jameson, R.J. and A.M. Johnson. 1993. Reproduc- tive characteristics of female sea otters. Marine other physical aspects of the habitat are with developing conservation strategies for Mammal Science 58:391-399. common limiting factors for other spe- sea otters over periods of mughly 50 to 100 Jameson, R.J., K.W. Kenyon, A.M. Johnson, and cies. Seaottersstrongly depress their prey years. The sea otter's futmappears bright at H.M. Wight. 1982. History and statusof translo- populations (Estes and VanBlaricom themoment, butonemustbemindfulofhow cated sea otter populations in North America. Society Bulletin 10: 100-107. 1985; VanBlaricom and Estes 1988) and misleading the short-term perspective can Jones, R.D., Jr. 1%5. Sea otters in the Near Islands, thus food limitation is often assumed to be be. For instance, even 100 years ago a Alaska. Journal of Mammalogy 46:702. the main factor regulating sea otter popu- concerned resource manager would have Kenyon, K.W. 1%9. The sea otter in the northeast- lations. While this is likely true, recent viewed the prospects for grizzly bears or em Pacific Ocean. North AmericanFauna, Num- ber 68: 352 pp. findings suggest that the interaction can gray wolves in North America in much the Lensmk, CJ. 1960. Status anddistributionof seaotters take complex and unexpected forms. For same way as we view sea otters today. in Alaska Trans. North American Wildlife and instance, while organic carbon produc- However, the ensuing century has demon- Natural Resources Conference 41:172-183. tion from kelp beds may ultimately fuel strated how wrong that perspective would Monson, D.H. and AR DeGange. 1995. Reproduc- tion, pweaning sunival, and sunival of adult sea the maintenance and growth of sea otter have been, and how wespecies and ottersatKodiakIsland,Alaska.CaoadianJoumalof populations (Duggins et al. 1989; Estes populations can be overlong periods of time. Zoology 721161-1169. 1990), poorly known relationships be- Pi- P., K. Ralls, andL. Fem 1988. Age determina- tween coastal currents and prey recruit- Literature Cited tion of Cahfnia sea otters fmm te& Chapter 6 in D.B. Siniff and K. Ralls, editors. PopuMon status Barabash-Nikifmv,I.I. 1947. Kalan Pages 1-174 in ment appear to modulate the linkage be- 0fCalifomiaseaotters.Minerals~tSer- Soviet Mhktmz RSFSR Glavnoe upravlenie po tween macroalgal-derived organic car- vice, ConW Repoa No. 14-12401-30033. zapovednikam. sea otter. Translated from Riedman, ML. and J.A. Estes. 1990. The sea otter bon production and sea otter abundance. Russian by A Birr0nandZ.S. Cole fortheNational (&hydra W):behavior, ecology, and natural These relationships, in turn, may explain Science Foundation by the Israel Program for Sci- history. U.S. Department of the Interior, Piand entificTramhtion,Jenmlem,Israel. 1962.227pp.l why high density sea otter populations Wildlife Service. Biological Report 90(14). Bodkin, J.L., D.M. Mulcahy, andCJ. Lensink. 1993. have persisted in some areas but not oth- Washington, DC. 126 pp. Agespecilic reproduction in female sea otters Ri~ML.,J.AEstes,M.M.SWu,A.A.kes, ers (Estes and Duggins 1995;Estes 1996; (EnhydraW) hm southcentral Alaska: analy- and D.R Carlson. 1994. Bre&ng patterns and Estes, unpublished data). Similarly, re- sis of reproductive tracts. Canadian Journal of productive success of California sea otters. The Zoology 71:1811-1815. cent work at Amchitka Island has shown Journal of Wildlife Management 58: 391-399. Caro, T.M. and M.K. Laurenson. 1994. Ecological that episodic food subsidies from the oce- Rottemm, L.M. and T. Si-Jackson.1988. Sea andgenetic factorsinconservation - acautionary otter. Pages anic realm can strongly influence the be- tale. Science 26385-86. 237-275 in J.W. Lentfer, editor. Se- lected marine mammals of Alaska National Tech- havior and population biology of sea ot- Cole, L.C. 1954. The population consequences of nical Information Service PB88-178462. life history phenomena. Quarterly Review of ters (Watt et al., submitted). Predation on Shenod, S.K., J.A. Estes, and C.M. White. 1975. Biology 29: 103-137. newborn pups by bald eagles (Sherrod et Depredation of sea otter pups by bald eagles at Crooks, K.R., M.A. Sanjayan, and D.F. Doak. In al. 1975) or on adult sea otters by killer review. Reassessment of the importance of cub Amchitka Island, Alaska. Joumal of Mammal- ogy 56:701-703. whales (Hatfield et al., in preparation) is predation for cheetah conservation. another potentially importantvariable, and Duggins, D.O., C.A. Simenstad, and J.A. Estes. Sin8,D.B. and K. Ralls. 1988. Population status of 1989. Magnification of secondary production by California sea otters. Minerals Management while predation may be negligible in many Service,Contract Report No. 14-12-001-30033. kelp detritus in coastal marine ecosystems. Sci- U.S. Fish and Wildlife Senice. 1996. Southem sea populations, it should not be overlooked. ence 245: 170-173. otter Finally, there is growing evidence that envi- Estes, J.A. 1990. Growth and equilibrium in sea mvery plan, 1996dra!l. Ven- CA42 pp. mnmental contaminants may be respon- otter populations. Joumal of Animal Ecology VanBlariwm, G.R. and J.A. Estes (editors). 1988. The community ecology of sea otters. Springer- sible for reduced growth rates and de- 59:385-401. Estes, J.A. 1991. Status of sea otter (Enhydra lulris) Verlag, Berlin, Germany. 247 pp. clines of local sea otter populations (Estes Wendell, F.C., R.A. Hardy, and J.A. Ames. 1985. populahons. Pages 27-35 in C. Reuther and R et al., in press; see Jarmanet al., this issue). Rochaeditors. F'mdingsoftheV. International Assessment of the accidental take of sea otters, These examples, while still equivocal, Otter Colloquium. Habitat Number 627-35. Enhydra lutris, in gill and trammel nets. Califor- Estes, JA1996. The influence of large, mobile preda- nia Department of Fish and Game, Marine Re- point out that any real understanding of the sources Op., 2 pp. tors in aquatic food webs: examples bmsea otters sea otter's demography must include com- and kelp forests. Pages 65-72 in S.P.R. Chmsm Jim Estes is with the National Biological Service and munity- andecosystem-levelinteractions. and M.L.Tasker, editors. Aquatic predators and the Institute of Marine Sciences, University of One broadgoal of wildlife research is their prey. Fishing News Books, Blackwell Scien- California, Santa Cruz, CA 95064, D. F. Doak: to develop strategies that help minimize tific, Oxfod, United Kingdom. Environmental Studies Board, University of Cali- Estes, J.A., C.E. Bacon, W.M. Jarman, RJ. Nmtmm, fornia, Santa Cruz, CA 95064; J. R. Bodkin and D. the likelihood of extinction on relevant RG. Anthony, and A.K. Miles. In press. Orga- Monson: NBS, Alaska Science Center, 1011 East time scales. Except for the rare effects of nochlaim in sea otters and bald eagles from the Tudor Road, Anclnnage, R J. Jameson: NBS, UX) environmentalcatastrophes, perspectives Aleutian archipelago. Marine Pollution Bulletin. S.W. 35th St., CorvaUis, OR 9333; J. Wan: Light- built around years or even decades are too Estes, J.A. and D.O. Duggins. 1995. Sea otters and house Field Station, Cromarty, IVll 8YJ, SCm- kelp forestsin Alaska: generality andvariationin LAND, T. Tinker: Tarestrial Marine Consulting Ser- short, especially for long-lived organisms a community ecological paradigm. Ecological vices, 79 Highst, Victoria, BC V8Z5C8, CANADA.

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Vol. 13 No. 12 1996 Endangered Species UPDATE 13 Monitoring the Status of the Wild Sea Otter Population: Field Studies and Techniques James L. Bodkin and Brenda E. Ballachey Fundamental to the conservation and describe those measures of population 20% consistently observed for translo- management of wildlife resources is an status that have been applied to sea otters cated populations in Southeast Alaska, understanding of a population's status, (see Table I), discuss theirrelative merits, Washington and British Columbia. both in terms of abundance relative to its and recommend directions for research Several types of data can be used to naturally occurring equilibrium level or that may improve our ability to accurately calculate rate of change. These are sum- carrying capacity, and rate of change monitor sea otter population status. marized below, with assets and liabilities (Caughley 1977; Eberhardt and Siniff noted for each. 1977). A variety of criteria for determin- Population parameters ing the status of wildlife populations have Distribution Measures of abundance beensuggested (Eberhardt and Siniff 1977; Observations of animals reoccupy- Estimates of relative abundance. Counts Hanks 198 1;Fowler and Siniff 1992),and ing areas they had historically inhabited, of sea otters have been made from shore, are summarized in Table 1. Proposed or of vacant habitat where they were pre- skiffs, larger boats, a variety of fixed- criteria includeboth direct measures, such viously present, is a clear indication of wing aircraft, and helicopters, or acombi- as the ratio of current abundance to carry- population change. Available informa- nation of these. It has been generally ing capacity abundance, andindices, such tion suggests that the Qstribution of otters recognized that some proportion of the as time-activity budgets or body condi- remains fairly stable over decadal time population is not observed during sur- tion, that may be indicative of population scales in equilibrium populations such as veys. In Prince William Sound, Udevitz status. Routine monitoring of population Amchitka, although abundance may vary, et al. (1995) demonstrated that 30% of the status improves management capabilities but that seasonal shifts may be pronounced sea otters present were missed during and may be particularly relevant to re- and possibly predictable. Change in dis- skiff surveys, because of avoidance by source conservation. tribution in growing populations appears otters and failure to observe otters present. Due to the recent history of exploita- less predictable, particularly in areas of It is likely that detection probabilities tion and recovery (see Anderson et al.; complex coastal physiography, such as differ among surveys, even if methods are Estes et al., this issue) and the resulting southeast Alaska, compared to popula- similar. Average sea otter detection prob- spatial separation of populations, sea ot- tions occupying more linear coastlines, abilities from fmed wing aircraft were ters in the north Pacific provide a unique such as California. Accurately describing ~0.50and varied widely both within opportunity to evaluate techniques for changes in distribution requires system- and among observers (Bodkin and monitoring population status. Within the atic population surveys that should in- Udevitz 1996; Bodkin, unpublished current range of sea otters, populations clude areas adjacent to occupied habitat. data). Consequently, if indices of abun- exist that have been at or near equilibrium dance are to provide unbiased estimates density for as long as 50 years (e.g., Rate of change of the proportional change in a popula- Architka, Alaska; see Figure 1). Other Population status may be inferred tion, the probability of detecting otters populations have recently attained equi- from the direction and rate of change in must be known for each survey. How- librium density (e.g., Bering Island, Rus- numbers in a population. Rate of change, ever, estimating detection probability sia and Prince William Sound, Alaska) resulting from the balance between re- can be difficult,and most surveys do not while others remainbelow (e.g., Olympic cruitment and mortality, likely reflects a account for undetected otters, compli- Peninsula, Washington; Vancouver Is- response to prior conditions rather than cating comparisons among surveys. land, British Columbia; and Southeast present, or future conditions. However, Alaska). The status of the mainland Cali- alterations in the rate of change might Estimates of absolute abundance. Esti- fornia population apparently remains un- provide some predictive power (e.g., a mating absolute sea otter abundance certain. The known variation in status population that continuesto grow, but at a through systematic sampling requires a among populations, a well described natu- decreasing rate, maybe approachng equi- method to estimate the proportion of ani- ral history, and the relative ease of enu- librium). Generally, remnant populations mals not detected while sampling. Bod- merating sea otters provide a solid foun- have experiencedslower growth rates than kin and Udevitz (1996) have developed dation for testing techniques to estimate translocated populations, or naturally re- an aerial survey method consisting of a sea otter population status. The results of colonized islands (Estes 1990a; Bodkin, strip transect design where all otters ob- research aimed at evaluating sea otter unpublished data). Annual growth rates served in a 400 m wide strip on one side of population status may be transferable to observed from several remnant popula- an aircraft are counted. The proportion of other wildlife populations, including en- tions range from about 5% (California) to otters not seen is estimated by conducting dangered species,which are not as readily 6-8% (Prmce William Sound and Kodialc) intensive searches within the strip studied. Our purpose in this paper is to to 13% at Arnchitka, compared to about transects. A similar procedure was at-

14 Endangered Species UPDATE Vol. 13 No. 12 1996 ulation Parameters Phvsiolo~icalParameters Behavioral Parameters

1. Distribution 1. Growth rates and individual size 1. Time activity budgets 2. Rate of change 2. Serum chemistry and hematology 2. Territory size 3. Measures of abundance 3. Deposited fat (kidney, 3. Group size 4. Reproduction bone marrow, fat mobilization) 4. Agonistic behavior 5. Survival rates 4. Disease 5. Food habits 6. AgelSex structures 5. Parasites 6. Infanticide 6. Immune response 7. Adrenocortical hypertrophy 8. Urinary excretion of hydroxyproline 9. Developmental stability (asymmetry) Table 1. Summary of indices proposed to estimate the status of a population relative to an equilibrium level (after Hanks 1981; Fowler and Siniff 1992). Techniques applied to sea otters are in italics. tempted from helicopters in Alaska habitats, density estimates should provide may prove useful in describing this rela- (DeGange et al. 1995). The aerial meth- an objective and direct measure of popu- tion. Additionally, a potential relation odology should be validated in a popula- lation status. Following complete between diving depths and population tion of known size, and may provide reoccupation, about 50 years ago, a de- status may exist. additional information on the California cline in density was observed at Amchitka Indices of density will result if the population. Island (Kenyon 1969). In 1991 at Bering survey method does not estimate the pro- Estimates of absolute abundance can Island, a 40% reduction in sea otter den- portion of sea otters not detected (Udevitz be important in population management. sity was observed following complete et al. 1995). Valid comparisons across or For example, sea otter abundance data reoccupation of the island during the 1980s within populations using an index require would have been of great value in deter- (A. Burdin, unpublished data). Estes the assumption that detection probabili- mining the magnitude of mortality from (1990a) used densities to evaluate the ties do not differ among surveys. It is the 1989Exxon VaMez oil spill (Ballachey recovery of seaotters at Attu Island. Com- unlikely that this assumption is valid. If et al. 1994; see Bonnell et al., this issue). parison of densities between Attu and detection probabilities can be estimated, Amchitka Island led Estes (1990) to &- unbiased estimates of abundance will re- Population census. Counts of sea otters velop a hypothesis regarding multiple sult. The results of a complete census or fromthe shore have generally been recog- equilibria, where sea otter densities an unbiased estimate of abundance will nized as the most accurate means of enu- reached a second, higher equilibrium den- result in unbiased density estimates that merating sea otter abundance. Estes and sity, following a diversification of diet. should be comparable within and among Jameson (1988) estimated the detection The possibility of multiple equilibria populations. probability of sea otters using standard- should be considered in interpretingtrends ized shore counts at 94.5%. This was the in population density. Reproduction first rigorous evaluation of this survey Estimation of density requires delin- Two specific reproductive attributes method, and provided a baseline against eating suitable habitat accurately. Poten- have been proposed as indices of sea otter which other methods couldbetested. Due tial sea otter habitat can be defined from population status:age at first reproduction to access constraints, however, shore- the high intertidal to a bathymetric con- and age-specific reproductive rates. Most based counts have limited application over tour beyond which sea otters cannot for- studies to date have found relatively the large areas occupied, or potentially age due to diving limitations. Our data consistent results among populations in occupied, by many sea otter populations. from Prince William Sound suggest that these variables. Generally, a small In California, a combination of a sea otters between the shoreline and the proportion of female sea otters reproduce census (ground count) and index of abun- 200 m contour interval are not evenly at age 2, most are mature by age 4, and dance (aerial counts) are combined to distributed. Approximately 80% of the age-specific rates are relatively high and provide annual minimum counts. These otters observed on surveys between the consistent among mature females counts are biased low to the extent that shoreline and the 200 m contour were (Rib and Estes 1990; Jameson and each method does not account for animals within the 40 m contour interval, which is Johnson 1993;Bodkinetal. 1993;Monson not detected. To retain comparability about a third of the total area. Until the and DeGange 1995; Monson 1995). over time (assuming relative abundance relation among the distribution of sub- Reproductive characteristics in fe- remains constant), it will be important to strate depths, habitat characteristics, and male sea offers have been studied through continue using each method proportional sea otter density is defined, the use of analysis of reproductive tracts and moni- to its use in previous surveys. density to compare populations should toring known individuals. Tract analysis be limited to areas of similar bathym- requires carcasses in good condition, Population density. Assuming equilib- etry and habitat. Data on the distribu- which usually are not available in large rium densities are similar among similar tion of dive depths of individual otters numbers. Monitoring lcnown individuals

Vol. 13 No. 12 1996 Endangemd Species UPDATE 15 Russia

Pacific Ocean

populations at or near equilibrium density other populations below equilibrium density

\ J Flgure 1. Map of the northPacific Ocean showing some sea otter populations near equilfbrlum density and others below equilibrium density. has been accomplished most efficiently (0.75-0.96) and have been obtained from (Rotterman and Monnett 1991) and 0.47 with the aid of radio telemetry. Adult monitoring known animals in California, (males) and 0.59 (females) in 1992/93 female reproductive rates are generally Kodiak and Amchitka (Siniff and Ralls (National Biological Service,unpublished high (0.80-0.94) among those popula- 1991; Monson and DeGange 1995; data) in western Prince William Sound. tions sampled (Schneider 1973; Jameson Monson 1995), and through analysis of During the same periods of study survival and Johnson 1993; Siniff and Ralls 1991; age structure of carcasses collected at rates in eastern Prince William Sound Bodkin et al. 1993;Monson and DeGange Amchitka (Eberhardt and Siniff 1988) were 0.33 (males) and 0.43 (females) in 1995; Monson 1995), and include esti- and in Prince William Sound, following 1990191 and 0.42 (males) and 0.89 (fe- mates from populations of differing status the Exxon Valdez oil spill (Udevitz et al. males) in 1992/93. At Amchitka, only 2 (California, Amchitka, Prince William 1996). Most studies have found higher of 11 (0.18) pups survived one year post- Sound and Kodiak). However, reproduc- survival rates in adult females, compared weaning (Monson 1995). These data tive rates appear to vary among ages, to adult males. suggest that juvenile survival rates are leading to the need torestrict comparisons Juvenile sea otter mortality can be lowest in populations that may be consid- to similar ages. Much less work has been evaluated in two components: through ered at or near equilibrium, and highest in done on aspects of male reproductive dependency, and after weaning. Depen- growing populations suchas Kodiak. Post- biology, although spermsamplescollected dent juvenile survival has generally been weaning juvenile survival appears to be in Prince William Sound indicate that estimated by following known females highly variable among years, as well as males may attain maturity as early as age 3 from pupping through weaning. Com- within sub-populations, based on the (Ballachey,unpublisheddata). In summary, parisons of pre-weaning survival rates Prince William Sound data. The Prince it appears that the qmdu%ve characteris- suggest variability among populations. William Sound data are difficult to inter- tics studied to date are relatively invariant, Estimates from California are 0.46 (Siniff pret because, in studies to date, potential and therefore unlikely to provide a sensitive and Ralls 1991), 0.64 (Jameson and oil effects cannot be separated from po- index to population status. Johnson 1993) and 0.60 (Rdman et al. tential area effects related to differences 1994);andfromAlaskaare0.85 at Kodiak in length of occupancy. However, if we Survival rates Island (Monson and DeGange 1995),and assume no chronic oil spill effect, the Survival rates, particularly of 0.29and0.54atAmchitka(Monson 1995). comparisons between western and east- juveniles, have been suggested as the life Post-weaning juvenile survival rates em Prince William Sound suggest juve- history variable most sensitive to estimated from Prince William Sound are nile survival may be a sensitive index of environmental conditions (Eberhardt 0.32-0.51 formales (Monnett 1988). Post- population status. Additionally, the large 1977;Hanks 1981). Annual survival rates weaning survival was an estimated 0.08 inter-annual variation observed in juve- among adult sea otters are generally high (males) and 0.21 (females) in 1990191 nile survival suggests we question the

16 Endangered Species UPDATE Vol. 13 No. 12 1996 assumption of a stable age distribution in from growing and equilibrium sea otter Serum chemistry and hematology seaotter populations (Eberhardt and Siniff populations. Results of recent research in Prior to the 1989 oil spill, blood 1988; Monson 1995). Russia, Amchitka and Prince William values (hematology and serum chemis- Ideally, amonitoring program would Sound suggests that body'condition (gen- try) of California sea otters had been include both periods of dependency and erally measured as the ratio of weight to reported (WilliamsandPulley1983; Wil- independency. If pre- and post-weaning length) may be useful as an indicator of liams et al. 1992). Subsequently, blood survival of pups are equally good estima- population status. For example, between data have been obtained on additional tors of population status, monitoring pre- 1980 and 1989 the Bering Island popula- populations, primarily in Alaska (Rebar weaning survival may prove more fea- tion grew at >20% annually, but by 1990 et al. 1995, 1996; National Biological sible for several reasons: (1) following it had apparently exceeded carrying ca- Service, unpublished data). Differences females through years may control for pacity, as a large scale mortality event have been identified between sea otter variability in pup survival among females; occurred during 1990191. During this subpopulations in Prince William Sound (2) up to three annual estimates could be period of population growth, the mean (in western and eastern areas) in serum gathered from a singletransmitter; and (3) weight of adult male carcasses declined enzymes and levels of certain white blood potential effects of surgical implants (if significantly at Bering Island (Bodkin cells (Rebar et al. 1996;National Biologi- any) should be less in adults than in pups. and Burdin, unpublished manuscript). In cal Service, unpublished data), but the However, given the variability in post- 1990, weights of adult males at Bering biological significance of these differ- weaning survival, and the possibility of Island did not differ from weights of adult ences at either the individual or popula- nearly complete failure of a cohort, we males collected in Prince William Sound, tion level is equivocal. Blood samples suspect that post-weaning survival may a population at or near equilibrium den- have been collected from several other be a more sensitive estimator of current sity. The number of otters at Bering sea otter populations in different stages of population status. Island has apparently stabilized at or near expansion. Comparison of blood values the number that persisted following the among populations, and relations with Physiological parameters 1990191 mortality event. other measures of population status, should Although physiological measures Although sample sizes were small, provide clarification of the utility of blood of population status have been consid- Monson (1995) found differences in the analyses for assessing populations. ered for many years (Hanks 1981; condition of adult female otters between Fowler and Siniff 1992),the 1989Exnon 1993and 1994at Amchitka Island. Cor- Immune response Valdez oil spill in 1989 in Prince Will- responding differences in pre-weaning Immunological measures have been iam Sound provided a major impetus to survival were also observed, with fe- developed to screen populations for ef- evaluate health of (1) individual sea males in better condition experiencing fects of toxic chemical exposure (Weeks otters captured for treatment and re- greater weaning success. In eastern et al. 1992). However, these techniques lease and (2) the wild population, for Prince William Sound, weights of moth- have not been applied to monitoring the indications of continuing deleterious ers of pups surviving at least 1.5 years status of wild populations when contami- effects of the spill. Examinations of were significantly greater than those of nants or disease are not a concern. Recent oiled sea otter carcasses demonstrated mothers of pups that died prior to 1.5 work in Prince William Sound demon- that exposure to oil (based on contami- years. Additionally, capture data sug- strated the feasibility of an in vitro lym- nation of the fur) was associated with gest that animals in more recently occu- phocyte proliferation assay using cells liver and kidney damage (Lipscomb et pied areas in the eastern Sound are isolated from blood of wild-caught sea al. 1993,1994). Thequestionremained, slightly heavier than those in areas of otters (P. Snyder, unpublished data); the however, whether sea otters in oiled the western Sound (National Biological technique is currently being applied to areas would have poorer survival rates Service, unpublished data). However, samples collected from Prince William and, if so, the time until health and we cannot discount the potential of an Sound subpopulations to evaluate poten- survival rates returned to pre-spill, nor- oil spill effect in observed differences. tial differences in status. mal values. To evaluate oil-related Review of the studiespresented above population damage and recovery, a se- suggest that the condition of animals in Other ries of studies on sea otters were imple- growing, as well as equilibrium popula- Other body fluids (urine, semen) have mented, primarily in Prince William tions may be a fairly sensitive index to been collectedfrom seaottersin southeast Sound (Ballachey et al. 1994). These short term changes in ecological condi- Alaska, and Prince William Sound studies are still ongoing (see the NVP tions experienced by the population, and (Ballachey 1995; National Biological project, below), and may provide in- may vary on time scales suitable for pre- Service, unpublished data) but have not sight into new approaches for assessing dicting change in population growth. Mea- been analyzed in terms of their relation- population status. suring body condition is a relatively non- ship to population status. invasive and simple procedure. Addi- Parasites have been frequently ob- Growth rates and individual size tional research relating body condition to served in necropsies of sea otters, includ- Kenyon (1969) first describeddiffer- survival rates and changes in abundance ing infestations in carcasses recovered ences in weights and lengths of sea otters may be justified. from high density areas at Amchitka

Vol. 13 No. 12 1996 Endangered Species UPDATE 17 (Rausch 1953) and Prince William Sound the proportion as well as the mean size sures potentially available to monitor (NationalBiologicalService, unpublished of urchins in the diet apparently decline population status. data). Although it may be anticipated as length of occupationincreases. Sirni- that parasite loads might increase as lar changes may occur with clams in Conclusion and densities increase, no published data soft sediment communities. Foraging recommendations exist on parasite levels in sea otter popu- on fish appears to be an attribute prima- Contemporary sea otter populations lations of differing densities, or on the rily of populations limited by resources, are generally recogtllzed by their geo- effect of parasite loads on survival and, but may be observed throughout the Aleu- graphic isolation. Although a population consequently, population growth. tian Islands. And lastly, there may be an may be perceived as "single1'because of As yet, the value of individual increase in prey species diversity, as popu- geographic considerations, it may not be physiological measures as estimators of lations become food resource limited. homogeneous in terms of population sta- population status, and their variability tus, particularly if available resources vary across populations in different stages of The "NVP" approach by location. Considerable variation in growth, are undetermined. Although In 1995, we (along with a large survival may exist among individuals if, measures evaluated to date may not number of other scientists) initiated a for example, juveniles born in the center prove to be useful tools for predicting study entitled "Mechanisms of Impact of a population's distributionhad a greater population status, they nevertheless and Potential Recovery of Nearshore distance to travel to unoccupied habitat should be valuable for assessing health Vertebrate Predators" (the NVP study). than juveniles born in areas closer to the of individuals and provide a tool for The primary objective is to determine boundaries of the populations's distribu- understanding factors that may be lim- the status of the near-shore marine eco- tion (assuming that a greater distance iting population growth. system in western Prince William Sound traveled decreases the likelihood of sur- affected by the Exron Valdez oil spill of vival). Consequently, when evaluating or Behavioral parameters 1989. Our approach is to compare popu- implementingmeasures of population sta- Time activity budgets lation, physiological and behavioral pa- tus, it may be prudent to consider the Considerable effort has been allo- rameters in four vertebrate predators, the potential for within population variation cated in evaluating time activity bud- harlequin duck, pigeon guillemot, river in status, particularly as remnant popula- gets as an index of sea otter population and sea otter, in oiled and nearby, unoiled tions increase in numbers and distribu- status (Loughlin 1979;Estes et al. 1982; portions of Prince William Sound, as in- tion. With this in mind we make the Ribic 1982; Estes et al. 1986; Garshelis dicators of the ecosystem's status. For sea following recommendations. et al. 1986; Ralls and Siniff 1988;Estes otters, we are estimating abundance and (1) Continuedmonitoringof popula- 1990b; Garshelis et al. 1990; Ralls and reproduction, body condition, bloodchem- tion trends is critical. Standardized sur- Siniff 1990; Gelatt 1996). Although istry and immune response, and foraging vey methodologies will accommodate conclusions have been equivocal, there success and prey selection. In addition, comparisons across populations. Survey does appear to be a general positive we are comparing sizes of sea otter prey in methodologies should be evaluated by relation between length of occupancy areas where otter populations were re- sampling populations of known size. and the proportion of time individuals duced and in areas where they were not. Unbiasedestirnates of abundance provide allocate to foraging. However, local en- Sea otter predation is widely recognized benefits in documenting magnitude when vironmental and seasonal effects poten- as limiting the larger size classes of some change occurs, particularly declines Erom tially may confound comparisons among invertebrate prey, such as sea urchins and events such as oil spills. populations. Differences in activity mussels (Riedman and Estes 1990). If sea (2) Our review of available data budgets among agelsex and reproduc- otter populations are reduced, prey popu- suggest that arelation exists between body tive status, as well as, local environ- lations might be expected to respond by condition and vital demographic variables, mental conditions, should be consid- increasing in size. We are using this such asjuvenile survival,that may predict ered in comparisons among populations. knowledge as a way to measure if the change in population abundance. This Both the apparent lack of sensitivity as affected sea otter population in Prince potential relation warrants additional con- an index and the extensive effort re- William Sound has recovered. Assuming sideration. quired in its estimation will likely limit sea otter densities, relative to carrying (3) At least three attributes of an the application of time activity budgets capacity, are similar between oiled and index of status are desirable: as an index of sea otter populations. non-oiled areas, we expect to see similar a. the method should be sustainable size distributions of prey. Sea otter recov- over time; Food habits ery may be indicated by similar prey sizes. b. the index should predict change, Relatively little work has been done The NVP study and other ongoing both direction and magnitude; and relating sea otter food habits to popula- efforts analyzing and comparing mea- c. the index should indicate cause of tion status. However, some generaliza- surements taken in sea otter populations change (e.g. intrinsic vs extrinsic). tions may be warranted. Sea urchins in different stages of expansion (ex- (4) Develop an understanding of the appear to be a preferred prey item of panding vs. at equilibrium) will provide fundamental processes that are structur- otters reoccupying former habitat, and further assessment of the array of mea- ing sea otter populations, including the

18 Endangered Species UPDATE Vd. 13 No. 12 1996 potential relation between dispersal dis- Fowler, C.W. andD.B. Siniff. 1992. Determining correlates in sea otters dying acutely in tance and population growth rates in ex- population status and the use of biological rehabilitation centers. Veterinary Clinical indices in the management of marinemammals. Pathology 32346-350. panding populations and factors constrain- Pages 1025-1037 in D.R. McCullough and Rebar, A. H., B. E. Ballachey, D. L. Bruden, andK. ing growth in equilibrium populations. R.H. Barrett, editors. Wildlife 2001: A. Klwcker. 1996. Hematology and clinical (5) Continue evaluation of the rela- Populations. Elsevier Applied Science, New chemistryof seaotterscaphuedinPrinceWiam tion between population status and indi- York, New York. 1163 pp. Sound, Alaska, following the Exxon Valdez oil Garshelis, D. L., J. A. Garshelis, and A. T. Kimker. spill. Exxon VaMez oil spill statelfederal natural ces using populations in differing stages 1986. Sea otter time budgets and prey resource damage assessmenthalrepoa(Marine of recovery as well as within populations relationships in Prince William Sound, Alaska. MammalStudy6),U.S.FishandWildlife Service, over time. Consideration should be given Journal of Wildlife Management 50:637-647. Anchorage, Alaska. 7 pp. to combinations of indices to improve our Garshelis, D. L., J. A. Ames, R. A. Hardy, and F. E. Riedman, M. L. and J. A. Estes. 1990. The sea otter Wendell. 1990. Indices used to assess status of (Enhydra lutris): behavior, ecology and natural ability to assess population status. sea otter populations: a comment. Journal of history. U.S. Department of the Interior, Fish Wildlife Management 54(2):260-269. and Wildlife Service. Biological Report90(14). Literature Cited Gelatt, T.S. 1996. Activity patterns and time Washington, D.C. 126 pp. Ballachey,B. E., J. L. Bodkin, and A. R. DeGange. budgets of sea otters at AmchitkaIsland,Alaska. Riedman, M. L., J. A. Estes, M. M. Staedler, A. A. 1994. An overview of sea otter studies. Pages M.S. thesis, University of Minnesota, Giles, andD.R. Carlson. 1994. Breedingpatterns 47-59 inT.R. Loughlin, editor. MarineMammals Minneapolis, Minnesota. 87 pp. andreproductivesuccess of Californiaseaotters. and the Exxon Valdez. Academic Press. San Hanks, J. 1981. Characterization of population Journal of Wildlife Management 58:391-399. Diego, California. 395 pp. condition. Pages47-73 inC.W. Fow1erandT.D. Ribic, C. A. 1982. Autumn activity of sea otters in Bodkin, J. L., D. M. Mulcahy, and C. J. Lensink. Smith, editors. Dynamics of large mammal California. Journal of Mammalogy 63702-706. 1993. Age-specific reproduction in female sea populations. John Wiley and Sons, New York, Rotterman, L. M. andC. Monnett. 1991. Mortality otters (Enhydra lW)hmsouth-central Alaska: New York. 477 pp. of sea otter weanlings in eastern and westem analysisof reproductivetracts. CanadianJoumal Jameson, R. J. and A. M. Johnson. 1993. Prince William Sound, Alaska, during the winter of Zoology 71(9):1811-1815. Reproductivechara~teristicsof female seaotters. of 1990-91. Exxon Valdez oil spill stawfederal Bodkin, J.L. and M.S. Udevitz. 1996. 1993 trial Marine Mammal Science 9: 156-167. natural resource damage assessment fmal report aerial survey of sea otters in Prince William Kenyon, K.W. 1969. The sea otter in the eastern (Marine mammal study 6-18), U.S. Fish and Sound, Alaska. Exxon Valdez oil spill Pacific Ocean. North American Fauna Number Wildlife Service, Anchorage, Alaska. 14 pp. restoration project final report (restoration 68.352 pp. Schneider, K. B. 1973. Seaotterreport. Federal aid project 93043-2), National Biological Service, Lipscomb, T. P., R. K. Harris, R. B. Moeller, J. to wildlife restoration project W-17-4. Alaska Anchorage, Alaska. 35 pp. M. Pletcher, R. J. Haebler, andB.E. Ballachey. Department of Fish and Game. Anchorage, Caughley, G. 1977. Analysis of vertebrate 1993. Histopathologic lesions in sea otters Alaska. Volume 11. 28 pp. populations. John Wiley and Sons, London, exposed to crude oil. Veterinary Pathology Siniff, D. B. and K. Ralls. 1991. Reproduction, United Kingdom. 234 pp. m1-11. survival and tag loss in California sea otters. DeGange, A.R., D.C. Douglas, D.H. Monson, and Lipscomb, T. P., R. K. Harris, A. H. Rebar, B. E. Marine Mammalogy Science 7:211-229. C.M. Robbins. 1995. Surveys of seaotters inthe Ballachey, and R.J. Haebler. 1994. Pathology Weeks, B. A., D. P. Anderson, A. P. DuFour, A. Gulf of Alaska in response to the Enron Valdez of sea otters. Pages 265-279 in T. R. Loughlin, Fairbrother, A. J. Goven, G. P. Lahvis, and G. oil spill. Exxon VaZdez oil spill state/federal editor. Marine mammals and the Exxon VaZdez. Peters. 1992. Immunological biomarkers to natural resource damage assessment final report Academy Press. San Diego, California. 395 pp. assess environmental stress. Pages 21 1-234 in (Marine mammal study 6-7), U.S. Fish and LournT. R. 1979.Radiotelemetricdetemi~tion R. J. Huggett, R. A. Kimerle, P. M. Mehrle, Jr. Wildlife Sewice, Anchorage, Alaska. 11 pp. of the 24-hour feeding activities of sea otters, and H. L. Bergman, editors. Biomarkers: Eberhardt, L.L. 1977. Optimal policies for Enhydra lutris. Pages 717-724 in C. J. Amlaner biochemical, physiological and histological conservation of large mammals, with special and D. W. MacDonald, editors. A handbook on markers of anthropogenicstress. SETAC Special reference to marine ecosystems. Environmental biotelemetry andradiotracking. Pergamon Press. Publication Series. Lewis Publishers, Chelsea, Comervation 4205-212. New York, New York. 804 pp. Michigan. 347 pp. Eberhardt, L.L. andD.B. Siniff. 1977. Population Monnett, C. W. 1988. Patterns of movement, Williams, T. D. and L. T. Pulley. 1983. dynamics and marine mammal management postnatal developmentandmortality of seaotters Hematology and blood chemistry in the sea policies. Joumal of Fisheries Research Board in Alaska. Ph.D. dissertation. University of otter (Enhydra lutris). Joumal of Wildlife Canada 54: 183- 190. Minnesota, Minneapolis, Minnesota. 134 pp. Diseases 19(1):44-47. Eberhardt, L.L. and D.B. Siniff. 1988. Population Monson, D. H. 1995. Reproductive strategies in Wiams, T. D., A. H. Rebar, R. F. Teclaw, and P.E. model for Alaska Penhula sea 0th~.OCS study sea otters at Amchitka Island, Alaska. M.S. Yoos. 1992. Influence of age, sex, capture MMS 88-0091, Minerals Management Service, thesis, University of California, Santa Cruz, technique, and restraint on hematologic mea- Alaska Region, Anchorage, Alaska. 94 pp. California. 60 pp. surements and serum chemistries of wild Cali- Estes, J. A. 1990a. Growth and equilibrium in Monson, D.H. and A.R. DeGange. 1995. fornia sea otters. Veterinary Clinical Pathology sea otter populations. Journal of Animal Reproduction,preweaningsurvival, andsurvival 21:106-110. Ecology 59:385-401. of adult sea otters at Kodiak Island, Alaska. Udevitz, M.S., J.L. Bodkin, andD.P. Costa. 1995. Estes, J.A. 1990b. Indices used to assess status of Canadian Joumal of Zoology 73: 1161-1169. Sea otter detectability in boat-based surveys of seaotterpopulations:areply. Joumal of Wildlife Ralls, K. and D. B. Siniff. 1988. Population status Prince WilliamSound, Alaska. MarineMammal Management 54(2):270-272. of California sea otter. OCS study MMS 88- Science 11(1):59-71. Estes, J.A. and R.J. Jameson. 1988. A double- 0021, Minerals Management Service, Pacific Udevitz, M. S., B. E. Ballachey, and D. L. Bruden. survey estimate for sighting probability of sea OCS Region, Los Angeles, California. 368 pp. 19%.Apopulationmodel for seaottersinwestern otters in California. Journal of Wildlife Ralls, K and D. B. Siniff. 1990. Tiebudgets and Prince William Sound. Exron Valdez oil spill Management 5270-76. activity patterns in California sea otters. Journal restorationproj~tWreport(restorationpjwt Estes, J. A., R. J. Jameson, and E. B. Rhode. 1982. of Wildlife Management 54(2):251-259. 93043-3), National Biological Service, Activity and prey selection in the sea otter: Rausch, R. 1953. Studieson the helminth fauna of Anchorage, Alaska. 34 pp. influence of population status on community Alaska. Xm. Disease in the sea otter with structure. American Naturalist 120:242-258. specialreferenceto Helminthparasites. Ecology --- Estes, J.A., K.Undemood, andM. Karmann. 1986. 34(3):584-604. James Bodkin and Brenda Ballachey are with the Activity time budgets of sea otters in California. Rebar, A.H., T.P. Lipscomb, R.K. Harris and B.E. National BiologicalService, Alaska ScienceCenter, Joumal of Wildlife Management 50:626-636. Ballachey. 1995. Clinical andclinicallaboratory 1011 E. Tudor Road, Anchorage, AK 99503.

Vol. 13 No. 12 1996 Endangered Species UPDATE 19 Organochlorine Contaminants in Sea Otters: The Sea Otter as a Bio-Indicator Walter M. Jarman, Corinne E. Bacon, James A. Estes, Mary Simon, and Ross J. Norstrom

Seaotters (Enhydra lutris) wereonce 1985). PCBs have also been suggested as involved with reproduction and age when distributed throughout the North Pacific having a role in the decline of river otters analyzing for organic contaminants in Rim from the Kuril Islands to Baja Cali- throughout muchofEurope(Mason 1989). female marine mammals (Addison 1989). fornia, with estimates of the worldwide The purpose of this study was to Seven sea otters died from uncertain population between 150,000-300,000in- determine if organochlorinecontaminants causes, one was shark bitten, and one died dividuals (Marine Mammal Commission could be contributing to the depressed of mating wounds. 1992; see Anderson et al., this issue). Fur rate of increase in the California sea otter Samples from Southeast Alaskan ot- harvesting duringthe eighteenth andnine- population. Unlike most previous con- ters were acquired by Native Alaskan teenth centuries nearly exterminated the taminant studies involving marine mam- hunters at Middle Island, Sitka Sound and species, and by the early 1900s the total mals, sea otters provide good subjects for Ogden Bay, Alaska, during May 1991. world population had been reduced to an ecotoxicological studies because they are Otters were shot, pelts removed, and tis- estimated 1,000-2,000 individuals; the non-migratory. Contaminant burdens sue samples were taken within 8 hours of California population was estimated at in sea otters should reflect their local death. Samples were collected from adult fewer than 50 animals (Kenyon 1969). habitats, in combination with metabolic male sea otters exclusively. Aleutian Since sea otters were legally protected in factors. Island sea otter samples were obtained 191 1 by the International Fur Seal Treaty Our approach was to compare from beach-cast carcasses at Adak and these remnant colonies, and others es- organochlorine contaminant levels in sea Arnchitka islands; one specimen was ob- tablished by relocations, have increased otter tissue among three separate tained in July 1992 from an individual (Estes 1990). populations across the North Pacific Rim who drowned during capture operations. The rates of recovery, however, have to determine if California sea otters have Aleutian samples were collected during differed among areas or populations. The ~i~cantlyhigher tissue organochlorine 1991 - 1992 and include 3 adult males and California sea otter population has in- levels when compared with populations 4 female sea otters of varying ages. creased at a rate of about 5% per year, in Alaska. Liver tissue from sea otters in compared with 17-20%per year for more California,Southeast Alaska, and Aleutian Results and discussion northerly populations (Estes 1990). The Islands (AdakandAmchitka, Alaska) were Polychlorinated biphenyls explanation for the depressed rate of in- analyzed for organochlorine pesticides Average total PCB levels (CPCB; crease in the California sea otter popula- (e.g., DDT and related compounds), sum of individual congeners) in sea otter tion is ambiguous and most likely polychlorinated biphenyls (PCBs) livers were highest in the Aleutian Islands complicated. Potential factors are (1) including non-ortho congeners (310 Wg), intermediate in California emigration; (2) reduced fecundity; and (NOPCBs), polychlorinated dibenzo-p- (170 Wg), and lowest in Southeast (3) increased mortality, possibly caused dioxins (PCDDs), polychlorinated Alaska (8 pgkg) (see Figure 1). CPCB at least partially by environmental con- dibenzofurans (PCDFs), and levels in both California and Aleutian sea taminants (Estes 1990). polychlorinated terphenyls (PCTs). otters were significantly higher than those Although the effects of environrnen- in Southeast Alaska (p4.05; all statisti- tal contaminants on sea otters is unstud- Sample collection cal results presented in this text based on ied, confamilial species, such as minks Biologists affiliated with the Califor- one way ANOVA). Though Aleutian sea (Mustela vison) and ferrets (Mustela nia Department of Fish and Game located otters had the highest WBlevels, this putorius firo), have been shown to be in Monterey, California routinely per- difference is not significant when com- extremely sensitive to several of these form necropsies on sea otters. Mortality pared to EPCB levels in California sea compounds (Platanow and Karstad 1973; categories are assignedandtissue samples otters (p>0.05). CNOPCB levels were Jensen et al. 1977; Wren et al. 1987). For are collected and archived. Liver samples highest in sea otters from California (33 example, experimental exposure of mink for this study were chosen according to pgkg), however, the three populations to PCB levels as low as 0.64 parts per the sea otter's sex, condition, year of death, could not be shown to differ signifi- million (ppm) in their feed caused nearly and mortality category. California sea cantly (p>0.05). complete reproductive failure (in these otter tissues were selected primarily from The California sea otter population is animals liver PCB levels averaged 1.2 adult male sea otters in relatively good located close to industrial activities. High ppm) (Platanow and Karstad 1973). Sea condition collected between the years levels of organic xenobiotics have been otter livers from central California were 1988-1991, with one female sea otter documented in the mid-latitudes of the found to have levels of PCBs which ex- included for comparison. Adult, male sea northern hemisphere and reflect exten- ceed 1.2 ppm (Hofman and Risebrough otters were chosen to reduce variability sive use and production of these chemi-

20 Endangered Species UPDATE Vol. 13 No. 12 1996 cals in these densely populated areas Organochlorinepesticides seaotters fromboth California and Alaska (Tanabe 1988; Bacon et al. 1992; In contrast with PCBs, XDDT (p,pt- (see Figure 1); the levels are highest in Norstrom and Muir 1994). Otter popu- DDT+p,pt-DDE+p,pt-DDD)levels were California sea otters, then Aleutian, and lations at Adak and Amchitka were cho- highest in Californiaseaotters (see Figure 1owestintheSoutheast~seaotters. sen for comparative study because of 1). Levels of DDTin California otters the extreme remoteness and presum- (850 Clglkg) are sigmficantly different Polychlorinated dibenzo-p-dioxins and ably pristine nature of the western Aleu- @

Vol. 13 No. 12 1996 EndsngHlsd Species UPDATE 21 Yet the islands of Adak and Amchitka pared to other marine mammals) rela- otter populations. Joumal of Animal Ecology have a history of military presence and tively sedentary, and tend to reflect local- 59:385-401. PCTs have been associated with a mili- Gallagher, K., R.C. Hale, J. Greaves, E.O. Bush, ized contamination. As high level and D.A. Stilwell. 1993. Accumulation of poly- tary base (Risebrough et al. 1990); there- predators they tend to biomagnify ambi- chlorinated terphenyls in aquatic biota of an fore, exposure at these islands could be ent contamination, making detection estuarine creek. Ecotoxicology and Environ- local. The central California coast has easier. Their role as a "keystone species," mental Safety 26302-312. substantial ship traffic, and since PCTs Hoffman, R.J. and R.W. Risebrough, editors. 1995. and their relationship to mink (a species Accumulationpattern of heavy rnetalsandchlo- have been associated with shipyards (de very sensitive to environmental contami- rinated hydrocarbons by sea otters, Enhydra Lappe et al. 1989), the source of PCTs to nants) make the sea otter a species worthy lutris, in California. Marine Mammal Commis- the central California coast could be re- of study as a bio-indicator. sion, 1625 Eye St., NW.,Washington, D.C. 20006. lated to shipping activities. Jensen, S., J. E. Kihlstrom, Olsson M, C. Lundberg, Acknowledgments and J. Orberg. 1977. Effects of PCB and DDT Conclusion Funding for this project was provided in on mink (Mustela vision) during the reproduc- Though CPCBs are not sigmficantly part by the California Department of Fish tive season. Ambio 6239. Kenyon, K.W. 1%9. The sea otter in the eastern different among otter populations in Adak and Game (Grant #FG0365), U.S.Fish Pacific Ocean. NorthAmericanFauna68:1-352. and Amchitka compared with California, and Wildlife Service, American Cetacean Le Boeuf, B.J. and M.L. Bonnell. 1971. DDT in they are still of concern to both California Society (Robert D.Bethel Fund), Friends California sea lions. Natme 234: 108-109. and Aleutian populations. Firstly, repro- of Long Marine Laboratory, and the Wil- MacGregor, J. S. 1976. DDT andits metabolites in the sediments off southern California Fisheries ductive problems and reduced kit survival liam Bey Hearld Fund. We acknowl- Bulletin 74:27-35. in minks have been correlated with PCB edge Jack Ames, Mike Kenner, Dan Marine Mammal Commission. 1992. Annual exposure at environmental levels. Munson, and Maria Sanches, for pro- Report to Congress., Washington, D.C. (Platanow and Karstad 1973; Aulerich viding sea otter tissue and assistance Mason, C.F. 1989. Watapollution and otterdistri- bution: A review. Lutm 3297-131. and Ringer 1977; Jensen et al. 1977; with dissections. Norstrom, R.J. and D.C.G. Muir. 1994. Chlori- Bleavins et al. 1980). Secondly, compar- nated hydrocarbons contaminants in arctic ma- ing PCB levels in Aleutian otters with Literature Cited rine mammals. The Science of the Total those in California may be misleading Addison, R.F. 1989. Organochlorines and marine Environment 154: 107- 128. Norstrom, R.J., M. Simon, and D.C.G. Muir. 1990. because the possibility exists that the in- mammal reproduction. CanadianJoumal of Fish- eries and Aquatic Sciences 46:360-368. P~ly~hlo~ated-p-dlo~i~~~and dibenwfurans in troduction of these compounds is com- Aulerich, R.J., and R.K. Ringer. 1977. bnt marine mammals in the Canadian north. Envi- paratively recent to the Aleutian status of PCB toxicity to mink, and effects on ronmental Pollution 66: 1-19. environment as opposed to California. their reproduction. Archives of Environmental Platanow, N.S. and L.H. Karstad. 1973. Dietary effects of polychlorinated biphenyls on mink. Their introduction to the Aleutians may Contamination and Toxicology 6279-292. Bacon, C. E., W. M. Jarman, andD. P. Costa. 1992. Canadian Journal of Comparative Medicine be so recent that population effects have Organochlorine and polychlorinated biphenyl 37:391-400. not been fully recognized. Recent eco- levels in pinniped milk from the Arctic, the VML.,J.A.Estes,M.M.Staeder,A.A.Oiles, logical data suggests that high pre-wean- Antarctic, California, and Australia. Chemo- and DR Carlson. 1994. Breeding pattern and I.eprodclctivesuccess of California sea oaers. Jour- ingpupmortality accounts fortheimpaued sphere 24779-791. Bleavins, M. R., R. J. Aulerich, and R. K. Ringer. nal of Wildlife Management 58:391-399. growth rate of the California sea otter 1980. Polychlorinatedbiphenyls (Aroclors 1016 Risebmgh, R., B. De Lappe, and C. Younghans- population (Riedman et al. 1994). Fur- and 1242): effects on survival and reproduction Haug. 1990. PCB and F'CT contamination in thermore, while sea otter populations in in mink and ferrets. Archives of Environmental Winter Quarters Bay, Antarctica. Marine Pollu- Contamination and Toxicology 9:627-635. tion Bulletin 21 No.11:523-529. the Aleutian Islands appear healthy and -. 1984. Effects of chronic dietary Tanabe, S. 1988. PCB problems in the future: thriving, Monson (unpublished data) has hexachlorobenzene exposure on the reproduc- foresight from current knowledge. Environmen- noted a high rate of pup mortality at tion performance and survivability of mink and tal Pollution -5-28. Amchitka. European ferrets. Archives of Environmental U.S. Fish and Wildlife Service. 1993. Draft Adden- dum to the Pacific Coast and Rocky Mountain/ Lastly, in addition to PCBs, seaotters Contamination and Toxicology 13:357-365. Cobb, G., D. Norman, and R. Kendall. 1994. Southwest American Peregrine Falcon Recov- from both California and the Aleutian Organochlorinecontaminantassessment ingreat ery Plans. U.S. Fish and Wildlife Service, Port- Islands had detectable levels of many blue herons using traditionaland nonlethal moni- land, Oregon. other organochlorines which could be toring techniques. Environmental Pollution Wren, C. D., D. B. Hunter, J. F. Latherland, and P. M. Stokes. 1987. The effects of p~lychlo~ated acting synergistically to impair the health 83:299-309. de Lappe, B. W., C. Younghans-Haug, J. Bott, and biphenyls and methyImen:ury, singly and in of these otter populations. Synergistic G. Ichikawa, editors. 1989. A Survey of Poly- combination on mink. 1I:Reproduction and kit effects of PCB exposure with compounds chlorinated Terphenyls (F'CTs) in San Francisco development Archives of Environmental Con- such as HCB and dieldrin, accompanied Bay, Los Angeles and San Diego Bay sediment tamhation and Toxicology 16449-454. by environmental stresses (e.g., severe andmussels. Trace OrganicsFacility, California Department of Fish and Game Long Marine Walter M. Jarman, Corinne E. Bacon, and James cold or food limitations) are documented Laboratory, U.C. Santa CNZ, Santa CNZ,Cali- A. Estes are at the Institute of Marine Sciences, in mink (Bleavins et al. 1984; Wren et al. fornia. Earth and Marine Science Building, University 1987; Cobb et al. 1994). DeLong, R. L., W. G. Gilmartin, and J. G. Simpson. of California, Santa CNZ, CA 95064. Mary We have shown that sea otters are 1973. Premature births in California Sea Lions: Simon and Ross J. Norstrom are at Environment association with high organochlorine pollutant Canada, Canadian Wildlife Service, National valuable in the study of contaminants for levels. Nature 181: 1168-1 170. Wildlife Research Centre, 100 Gamelin Blvd. several reasons. They are (when com- Estes, J.A. 1990. Growth and equilibrium in sea Hull, Quebec KlAOK3.

22 Endangered Speck UPDATE Vol. 13 No. 12 1996 The Risk of Disease and Threats to the Wild Population Nancy J. Thomas and Rebecca A. Cole

The growth of the southern sea ing, fighting and mating activities were examined at the NWHC. Twenty per- otter population has been steady, but documented. Pup abandonment and a cent died from traumatic injuries. An- slow in comparison to Alaskan subspe- variety of miscellaneous conditions and other 10% were emaciated at death and cies, and range expansion in California diseases were recorded. Since 1992, no specific cause for their debility could has faltered. Slower growth is occur- laboratory diagnostic efforts at the Na- be identified. Miscellaneous conditions, ring in California despite birth rates tional Wildlife Health Center (NWHC), such as neoplasia, or gastrointestinal or comparable to those in Alaska, so biolo- Madison, Wisconsin, supplementedthe urinary obstructions, accounted for gists have reasoned that mortality is stranding network's activities in Cali- 13% of the mortality. In 18.5% of the hindering the growth of the California fornia, so that knowledge about the animals no cause of death could be population (Riedman and Estes 1990; causes of mortality has been further ascertained. see Estes et al., this issue). In order to refined. It is these recent perspectives Traumatic causes, emaciation and investigate this issue, research efforts on the causes of mortality in the south- a variety of miscellaneous conditions have been directed toward identifying ern seaotter that are outlined here, along were similar to those described in sea the causes of death in southern sea with consideration of their implications otters in the past. Ames summarized the otters. for sea otters and the Pacific marine causes and distribution of traumatic in- Several major causes of mortality ecosystem. juries in sea otters examined from 1968 in the southern population were recog- to 1989 (as presented in Riedman and nized in the past and are currently being Causes of mortality Estes 1990). The most frequently iden- addressed. These include protections Since 1992 approximately50 south- tified cause of trauma in the past was from overharvesting and accidental en- ern sea otter carcasses per year were shark attack (Ames andMorejohn 1980); tanglements in fishing gear, as well as examined at the NWHC as part of a 5 the shark-bitten sea otters were col- oil spill prevention and contingencies. year intensive necropsy study. Car- lected throughout the range but the larg- Still to date, the problem of slow popu- casses were selected for the NWHC est proportion were found north of Point lation growth and expansion persists. study on the basis of good postmortem Sur. In the recent study shark attack The California Department of Fish condition from the approximately 110 was also the most frequently diagnosed and Game has studied sea otter mortal- to 160 carcasses found per year in Cali- source of trauma (7% of all mortality, ity since 1968. A salvage network, fornia. At the NWHC, microscopic n=14), and more than 70% of the shark- maintained through the cooperation of examination supplemented gross exami- bitten sea otters were found north of State and Federal agencies and scien- nation of the carcasses and a variety of Point Sur. In the past, gunshot injuries tific institutions, verified beach-cast car- laboratory techniques in bacteriology, were documented predominately south casses and examined them to estimate virology, parasitology, and toxicology of Cambria. Ames speculated that the the causes of death. By 1989 nearly were conducted to arrive at a diagnosis. frequency of shark attacks in the north- 1700 dead sea otters had been docu- By this means a greater proportion of ern extent of the range and gunshot mented (see Table 1; Ames et al. 1983, the animals with inapparent causes of mortalities in the south may have an unpublished data; Riedman and Estes death were diagnosed. Only a prelirni- impact on range expansion (as presented 1990). Substantial mortality from net nary analysis of the 1992-95 data has in Riedman and Estes 1990). Gunshot drownings was identified and the preva- been done, but some interesting pat- was diagnosed in 4% (n=8) of the sea lence of trauma from predators, shoot- terns are emerging from the 195 cases otters in the recent study but these cases studied (and additional were equally distributed between the samples have been col- range south of Cambria and north of Trauma 18.'% lected through 1996). Point Sur. shark attack 12.0% gunshot 4.6% The proportionate mating 2.3% causes of mortality iden- Infectious disease Fishing netlline 4.6% tified at the NWHC bore The high frequency of infectious Dependent animals 16.5% similarities to past data diseases (38.5%, n=75) was unexpected. Natural causes 4.0% but also had interesting Many of these diseases were reported Undetermined 56.0% differences (see Figure but uncommon in the past. Peritonitis 1). Various parasitic, induced by acanthocephalan parasites Table 1. Sea otter mottallties from 1968-1989 (n=1,680), fungal, or bacterial dis- taken from Ames 1983 and Riedman and Estes 1990. (see below) was the diagnosis for 14% eases caused the deaths (n=27) of the sea otters examined at the of 38.5% of the sea otters NWHC, comprising the single most fre-

Vol. 13 No. 12 1996 Endangered Species UPDATE 23 Infectious Disease 38.5% ver, is endemic in certain arid regions of the Southwest U.S., notably the Central Valley of California. This fungus grows in soil to form arthrospores that produce disease when inhaled by susceptible individuals. Coccidioidomycosis most Trauma 20.0% often manifests itself in the respiratory tract, but many organs, including the brain, may be affected. A wide variety Emaciation of species, including humans, are sus- ceptible to coccidioidomycosis. The results of exposure vary, depending on both species and individual factors, from no ill effects to death. In all sea otter Undetermi neous 13.0% cases the infection was widely dissemi- Figure 1. Causes of mortality in southern sea otters from 1992-1995 (n=l95). nated to affect multiple organs. quent cause of death, as well as the most brain was associated with intermediate The deaths of 12% (n=23) of the frequent infectious disease. Most (67%, stages of protozoal parasites. The char- otters were attributed to various bacte- n=18) cases of acanthocephalan perito- acterization of this disease syndrome rial infections. The affected sea otters nitis occurred in pups or juvenile sea was confounded by the fact that the were all adult or subadult. Bacterial otters. Peritonitis occurs when larval protozoan (Toxoplasmagondii) was iso- infections were manifested primarily as acanthocephalan parasites that reside in lated from the brains of sea otters with pneumonia, heart valve infection, ab- the intestine aberrantly migrate through and without encephalitis. Immunohis- scess or septicemia. The origins of the intestinal wall allowing bacteria to tochemical tests indicated that a second infection were likely to be inhalation or infect the abdominal cavity. Addition- protozoan was present in some of the traumatic injuries, but were inapparent ally, in many of these cases, thousands cases, suggesting that two agents may in most cases. Bacterial infections oc- of acanthocephalans were embedded in be involved. In each year of the recent curred as individual cases with no ap- the intestinal wall, and there was pro- study, encephalitis cases were restricted parent links among them, so direct trans- fuse bloody enteritis. The parasite caus- to the spring and summer. The means of mission between sea otters was unlikely. ing this condition, Polymorphus spp., transmission of these agents to sea ot- The most frequently isolated bacteria belongs to one of two genera of acan- ters is unknown. The typical infectious were different strains and species of thocephalans found in southern sea ot- stage, the oocyst, of T. gondii is shed in Streptococcus, but the agents varied ters (there is a current taxonomic dis- the feces of a species-specific definitive widely and mixed infections in the same pute on the Polymorphus species iden- host, the cat. Intermediate stages of individual were common. tification). The other, Corynosoma several protozoan agents are found in enhydri, was found frequently but animal tissues and may also be directly Significance of disease caused no detectable deleterious effects. infectious if ingested. The intermediate The implications of the recent Acanthocephalans are transmitted to sea stage of T. gondii is found in a wide necropsy results appear complex. Past otters through invertebrate intermedi- variety of vertebrates including humans mortality surveys suggested that the in- ate hosts. The spectrum of invertebrate world wide, but serious illness from fluences of "natural" (that is, not di- hosts of Polymorphus spp. is unknown. the infection is sporadic. Illness is rectly human-inflicted) mortality might Polymorphus spp. were reported in small more common in the very young, aged, be significant (Ames et al. 1983). The numbers (2-206 per otter) in 10% of the or as a complication of impaired im- preliminary data presented here cor- southern sea otters examined by mune function. roborate that mortality from natural Hennessy and Morejohn (1977). Both Eight cases of coccidioidomycosis causes, specifically infectious diseases, the prevalence and intensity of (4% of all mortality), a systemic infec- is occurring at a high rate. Disease Polymolphus spp. infections appear sub- tion caused by the fungus, Coccidioides mortality is not only frequent but some stantially greater in recent years. immitis, were diagnosed from 1992-95 diseases appear to be on the rise while Protozoal encephalitis was the (Thomas et al. 1996). Only one case others are newly reported. Several of cause of death in 8.5% (n=17) of the sea had been reported previously, in 1976 the diseases are predominately affect- otters examined at the NWHC. This is (Cornell et al. 1979); this may be an ing prime age, breeding adults. Taken the first report of this organism or dis- emerging problem. The affected sea in total, the findings regarding infec- ease in sea otters. Most (88%, n=15) of otters were adult or subadult. All 8 sea tious disease mortality appear to bear the affected otters were adults or sub- otters, and the prior case in 1976, were some disturbing implications for sea adults. Otters with encephalitis had no found at the southern end of the range at otters. The immediate questions are gross evidence of the condition but, San Luis Obispo County. The disease, whether this frequency is truly unusual microscopically, inflammation in the also known as San Joaquin Valley fe- and whether it is remediable.

24 Endangered Species UPDATE Vol. 13 No. 12 1996 In comparison to endangered ter- disease agents and means of exposure certain sea bird populations, or factors restrial top-level predators, these re- differ, as do the reasons why an appar- inducing bird aggregations (for example, sults are unusual, and, at the moment, ent increase or emergence might be beach utilization by humans, distribu- there is no comparable data available taking place. Exposure rates may be tion and management of landfills, ag- for other, more vigorous sea otter popu- linked to population density for certain gregation of crab species or other food lations. The NWHC is carrying out diseases but density-independent for items). similar mortality studies on gray wolves others. Identification of the key factors (2) Factors influencing intermedi- (Canis lupus) in the Great Lakes Re- that affect exposure and the signifi- ate hostpopulations. A larger infected gion and for the red wolf (Canis rufus) cance of each disease in relationship to intermediate host community (as in- reintroduction program. In these terres- population dynamics will be impor- creased prevalence and/or larval acan- trial species the greatest proportion of tant distinctions to make if we are to thocephalan burdens) could be related mortality (55% for gray wolves and arrive at effective mortality-reduction to an increase in infected birds that 42% for red wolves) is accidentally or strategies. contaminate the beaches with feces and intentionally human-inflicted by shoot- acanthocephalan eggs. Add to this the ing, trapping, poisoning, or vehicle Polymorphus spp. complicating fact that some trauma. Infectious diseases cause a Over the last 5 years the prevalence acanthocephala species alter their inter- relatively minor proportion of the mor- and intensity of Polymorphus spp. in- mediate host's behavior, thereby increas- tality in these species, at a rate of 9% in fections in otters and the frequency of ing the risk of predation so that birds gray wolves and 8% in red wolves. extraintestinal migration of prey disproportionately on infected The question of whether the sea acanthocephala has increased. In order crabs. Certain conditions such as a rise otter's disease mortality has a remedy is to understand this increase in deleteri- in water temperature and phytoplank- not readily answered in our current state ous Polymorphus spp. infections in sea ton proliferation can favor the survival of knowledge. Missing details about otters, we need to examine the predator- of crab offspring, thereby providing a the transmission cycles of the more fre- prey dynamics of the definitive host larger intermediate host community for quently encountered diseases may pro- species (sea birds) and probable inter- potential infection. vide the keys to effective control mea- mediate hosts (crabs). It is this preda- (3) Factors affecting the sea otter sures. Before focusing on the transmis- tor-prey relationship that the population. A food habit change by sion cycles of individual diseases, it Polymorphus spp. depend upon for some sea otters could increase their may be useful to consider the underly- completion of the life cycle. Prelimi- predation on infected crustaceans. This ing significance of a high rate of infec- nary data suggest that Emerita analoga prey selection might occur if more opti- tious disease from a broad perspective. and Blepharipoda sp. of crab are two mal prey items were unavailable or they In order to exhibit a high frequency and intermediate hosts for this acanthoceph- may be taken by inexperienced or inca- variety of infectious disease mortality, alan, however there may be more inver- pacitated sea otters that seek easier prey are southern sea otters highly vulner- tebrate species involved. Birds such as such as Emerita and Blepharipoda. able to many diseases or are they under- gulls, scoters and sea ducks prey upon A combination of two or more of going high rates of exposure? infected crabs and harbor the egg-pro- the above factors may be interacting to A state of general susceptibility is ducing adult Polymorphus spp. The cause an increase in the parasitism of suggested by the variety of infections eggs are deposited with feces into the the sea otter. Given the complexity of encountered in sea otters. Unusual vul- environment. Sea otters can become the ecology influencing the predator- nerability is also suggested by the fact infected with the Polymorphus spp., by prey dynamics, several species of in- that otter deaths are repeatedly attrib- eating the infected crabs, however, the vertebrates and vertebrates need to be uted to diseases that are expected to sea otter is a dead-end host and no egg- considered in order to identify the fac- cause only sporadic mortality in other producing acanthocephalans have tors influencing the sea otter's species. Generalized vulnerability to been found. Abiotic or biotic factors Polymorphus spp. infections. infections implies that immune func- that influence the population densi- Eradicating Polymolphus spp. from tion is ineffective. Although assessing ties and predator-prey interactions of the normal bird and invertebrate hosts and understandingthe exact mechanisms the bird, invertebrate hosts, or sea would be impossible. However, a re- of immune function impairment is com- otters could affect the risk of infection versal of the sea otter's current mortality plicated, in general, immunologic de- in sea otters. trend from Polymorphus spp. is feasible fects may be congenital or have a ge- There are three broad facets to ex- if we could reduce the prevalence of this netic basis, or arise from certain viral amine to determine why increases may parasite. Effective management strate- infections, environmental toxins, or mal- be occurring in otters. gies may be to disperse the responsible nutrition. (I)Factors impacting birdpopula- bird species or increase the availability The factors that affect the rates of tions. A larger infected bird population of alternate uninfected prey species to infectious disease exposure in sea otters (as higher prevalence and/or higher sea otters. However, before such man- differ among the different diseases en- acanthocephalan burdens) could be due agement strategies can be developed countered. The potential sources of the to factors that caused an increase in basic questions must be answered, in-

Vo1, 13 No. 12 1996 Endangered Species UPDATE 25 cluding which crab species act as inter- Australian marsupials or arboreal New human-related factors, so occurrence in mediate hosts, which beaches have World monkeys) that evolved isolated sea otters may lend support to that highly infected intermediate or defini- from felids or their feces. Subadult and hypothesis. Prospects for control of this tive host communities, and what factors adult sea otters, not just the young or disease in sea otters are not promising, but correlate with the distribution of in- aged, had protozoal encephalitis, so age knowledge about coccidioidomycosis fected sea otters. does not appear to be an important fac- prevalence has predictive value that may tor. Sea otter immune competence has particularly apply to the population in Toxoplasma gondii not been well studied, so its status to the southern extent of range. The source of Toxoplasma gondii date is unknown. Regarding the species Many of the infectious diseases of exposure to sea otters is most likely experience with T. gondii, there is little concern in southern sea otters are not oocysts from cat feces. Transmission information. Most reports of T. gondii species specific; they may affect other by preying on infected intermediate infection of marine mammals are from marine mammals, sea birds and human hosts is unlikely because only warm- captive animals. However, reports of beings. Some of the epizootiologic fac- blooded animals have been reported as this protozoan causing disease in the tors that potentially play a role in pro- intermediate hosts, and the sea otter is wild northern fur seal (Callorhinus moting disease emergence or frequency reported only rarely to eat birds. Sea ursinus) (Holshuh et al. 1985),the West in otters also may have broad effects in otters could ingest oocysts in water con- Indian manatee (Trichechus manatus) the marine environment. The success- taminated with cat feces through run- (Buergelt and Bonde 1983) and five ful recovery of the southern sea otter off from beach soils, or possibly by species of dolphin (Di Guardo et al. population is of immediate concern, but eating filter feeding invertebrates that 1995) indicate that other wild marine obstacles to their recovery could have are transporting oocysts in their alimen- mammals are also exposed to T. gondii. wider implications for the marine eco- tary tracts. If oocysts are entering the Regardless of whether resistance to toxo- system. The sea otter could be a sensi- water via sewage effluent, the contami- plasmosis is an individual or species tive indicator of the health of the Pacific nation of the marine ecosystem could be phenomenon, we can evaluate the sea near-shore marine ecosystem. much greater than just that from beach otter's degree of susceptibility by evalu- or adjacent shoreline run-off. This ating the frequency of exposure. Such Conclusions and would be an important source to iden- studies would help discern if most ot- recommendations tify and is potentially manageable. To ters are exposed to T. gondii and resist The following series of recommen- investigatethe connection between sew- disease or if the few that are exposed dations are proposed as means to assess age disposal and otter exposure, the break with disease. the impact and implications that have survivability of oocysts through local arisen from investigations into sea otter sewage treatment systems and the vi- Coccidioides immitis mortality. ability of oocysts in sea water should be The occurrence of infections by the (1) Complete the 5 year intensive evaluated. Temporal studies could de- soil-associated fungus, Coccidioides necropsy study. The 5 year database termine whether peaks in contamina- immitis, in the marine environment is under development at the NWHC will tion correlate with seasonal patterns of puzzling. The means of transmission to be completed at the end of 1996. The disease. Laboratory studies could be sea otters presumably is similar to that recent health and mortality data have designed to investigate whether crabs in other species, specifically by undergone only preliminary evaluation. and other crustaceans could act as inhalation of airborne arthrospores. Further analyses for age, gender, and phoretic agents in the transmission of T. Recurrent dry winds from the east may temporal and geographic differencesare gondii to sea otters. Vertical transmis- disperse the spores from the soil in necessary to distinguish significant pat- sion of T. gondii from mother to off- endemic sites around the city of San terns and compare with previous data. spring can cause abortion in sheep, Luis Obispo or in the San Joaquin Valley. (2) Analyze the population data. goats, and humans. Toxoplasmosis in Coccidioidal spores survive and may Further examination of recent necropsy the very young sea otter may be under- even grow in salt water, so the data by integration with other mortality represented in post mortem sampling accumulation of spores in the marine and demographic data may provide valu- because carcasses of fetuses or neo- environment has also been postulated able insight into the significance of dis- nates are less likely to be found (Dzawachiszwili et al. 1964). The ease and the role of mortality in popula- (Riedman and Estes 1990). apparent increase in prevalence of tion recovery. The relationship between Toxoplasmosis, may be more than coccidioidomycosis in sea otters since the various infectious disease condi- the other diseases, raises concern about 1992 may be due to the application of tions and population dynamics needs to the sea otter's general ability to resist more sensitive diagnostic methods, but be explored. Identification of mortality disease. Infection with T. gondii does it coincides with a marked increase in factors with the greatest potential for not always cause disease in the host. human cases in 1991 to 1993. The limiting population growth should guide Disease and death more often occurs in human outbreak was tentatively research priorities. animals that are vulnerable due to age, attributed to unusual weather and (3) Identify key factors in the dis- irnrnuno-compromise,or in species (e.g., environmental conditions rather than ease cycles. The key to reducing mor-

26 Endangered Species UPDATE Vol. 13 No. 12 1996 tality in the southern sea otter may be the patterns in sea otter mortality. The nants in sea otter disease vulnerability, found by identifying critical points at activities of the sea otter stranding net- debility, or neoplasia. which important disease transmission work are critical to that end. cycles can be interrupted by knowl- (6) Evaluate the rates of disease Acknowledgments edge-based management strategies. The exposure. By comparing the rates of We thank Lynn H. Creekmore and Carol greatest gaps involve the transmission disease exposure to the rates of disease U. Meteyer for their contributions to of acanthocephalan peritonitis and pro- mortality we can evaluate the general both the data collection and develop- tozoal encephalitis. Elucidation of dis- vulnerability of the southern sea otter to ment of concepts. ease cycles may also provide a measure infectious disease. of the role of human intervention or (7) Assess immunefunction. Evalu- Literature Cited human responsibility in the emergence ation of the adequacy of the wild south- Ames, J. A. and G. V. Morejohn. 1980. Evidence of sea otter disease. ern sea otter's immune function is a of white shark, Carcharodon carcharias, attacks on seaotters, Enhydra lutris. California (4) Develop comparative data. means to investigate whether general- Fish and Game 66: 196-209. Comparison with similar data from a ized vulnerability to infectious disease Ames, J. A., R. A. Hardy, F. E. Wendell, and J. J. more vigorous sea otter population exists. Geibel. 1983. Seaotter mortality inCalifornia. would provide another means to assess (8) Assess environmental contami- Report of the Marine Resources Division, California Department of Fish and Game, the significance of mortality and vari- nant exposure. Otter tissue analyses for Monterey, California. 49 pp. ous mortality factors to the southern sea organochlorine compounds and heavy Buergelt,C.D. andR.K. Bonk. 1983. Toxoplasmic otter population. The best comparison metals were discontinued in 1980. No meningoencephalitis in a West Indian manatee. would include both the causes and rates serious threats to sea otter health were Journal of American Veterinary Medical Association 183:1294-1296. of mortality. revealed in these early analyses. Evalu- Comell, L. H., K. G. Osborn, and J. E. Antrim, Jr. (5) Continue mortality monitor- ation of recent environmental contami- 1979. Coccidioidomycosisin a California sea ing. Continuation of a mortality moni- nant burdens in sea otters in correlation otter (Enhydra lutris). Journal of Wildlife toring system is the basis for identifying with mortality factors is a means to Diseases 15373-378. Di Guardo, G., U. Agrimi, L. Morelli, G. Cardeti, trends, investigating, and interpreting assess the current role of toxic contami- G. Terracciano, and S. Kennedy. 1995. Post mortem investigations on cetaceans found stranded on the coasts of Italy between 1990 and 1993. Veterinary Record 136:439-442. Dzawachiszwili, N., J.W. Landau, V.D. Newcomer, andO.A.Plunkett. 1964.Theeffect of sea water and sodium chlorideon the growth of fungi pathogenic to man. Journal of Investigative Dermatology 43: 103-109. Hennessy, S. L. and G. V. Morejohn. 1977. Acanthocephalan parasites of the sea otter, Enhydra lutris, off coastal California. California Fish and Game 63:268-272. Holshuh, H. J., A. E. Sherrod, C. R. Taylor, B. P. Andrews, and E.B. Howard. 1985. Toxoplasmosis in a feral northern fur seal. Journal of American Veterinary Medical Association 187:1229-1230. Riedman, M. L. and J. A. Estes. 1990. The sea otter (Enhydra lutris): behavior, ecology, and natural history. U.S. Departmentof theInterior, U. S. Fish and Wiife Service Biological Report 90(14). Washington, D.C. 126 pp. Thomas, N. J., D. Pappagianis, L.H. Creekmore, andR.M.Duncan. 1996. Coccidioidomycosisin Several photographs for this issue of the Endangered southern sea otters. In press in H.E.Einstein, D. Pappagianis, and A. Catanzaro, editors. Pro- Species UPDATE were provided by ceedings of the Fifth International Conference Jeff Foott Productions on Coccidioidomycosis. National Foundation and can be ordered as color prints from the for Infectious Diseases, Bethesda, Maryland. photographer at:

P.O. Box 21 67 545 S. Willow Nancy J. Thomas andRebecca A. Cole work with Jackson, WY 83001 theU.S. Geological Survey, BiologicalResources (307)739-9383 Division and can be reached at National Wildlife Health Center, 6006 Schroeder Road, Madison, Wisconsin 5371 1.

Vol. 13 No. 12 1996 Endangered Species UPDATE 27 Overview of the Legislative Mandates and the Agencies Responsible for Implementation of Southern Sea Otter Protection Under the Endangered Species Act Jamie Rappaport Clark

When Congress passed the Endan- life. NMFS is generally responsible for existing regulatory mechanisms;or other geredspecies Act (ESA; 16U.S.C. 1531 most marine species, except birds, and natural or man-made factors affecting et seq.) in 1973, it set clear public policy the FWS is generally responsible for the species' continued existence. that we were to act to prevent the de- birds and terrestrial and freshwater spe- In order to list a species, the FWS struction of nature's diversity. The ESA cies. The southern seaotter is anexception, must follow a strict legal process known is one of the most comprehensive pieces however, and along with the West Indian as a "rulemaking procedure." Changes or of environmental legislation ever en- manatee and sea turtles (on land), remains additions to the list are accomplished acted by Congress, calling for the under the FWS's jurisdiction. through a rulemaking process involving conservation of threatened and endan- Protecting endangered and threatened publishing a proposal in the Federal Reg- gered species, and, more importantly, species and restoring them to a secure -ister, allowing opportunity for public the ecosystems upon which they de- status in the wild is the primary objective comment (including holding public hear- pend. The ESA also established a strong of the endangered species program. En- ings) and adoptionof a finaldetermination. leadership role for the federal govern- dangered species responsibilities for both To ensure that all potentially interested ment in the conservation of species at NMFS and FWS include listing, reclassi- parties are made aware of the proposal, risk of extinction. To accomplish the fying, and delisting species; providing the FWS issues news releases, conducts objectives of the ESA, Congress envi- biological opinions to federal agencies on special mailings, and directly informs the sioned a network of international, activities that may affect listed species; scientific community and other federal national, federal, state, and private or- enforcing species protection; providing and state agencies. A final rule listing the ganizations working toward common technical assistance to the states and other species as endangered or threatened must goals. Coordination among these agen- non-federal applicants in the develop- be published within one year of the pro- cies and organizations, private ment and implementation of habitat posal, with a possible six-monthextension individuals, and major land users is per- conservation plans; overseeing recov- to gather more data if there is scientific haps the most essential ingredient for the ery activities for listed species; providing conflict, or the proposal must be with- successful implementation of the ESA. for the protection of important habitat; drawn. The ESA provides that listing Fundamentally, the ESA is habitat- and providing grants to states to assist decisions must be based solely on the oriented. It seeks to conserve "the with their endangered species conser- basis of the best scientific and cornrner- ecosystems upon which endangered spe- vation efforts. cial data available. cies and threatened species depend." The southern sea otter was listed as This orientation has been embraced by Listing threatened in 1977 due to its small popu- the federal government in its increased The listing process is one of the basic lation and limited distribution, and to efforts to address listing and recovery functionsperformed by the FWS in carry- threats from oil spills, pollution, and com- on a multi-species, ecosystem-wide ba- ing out its responsibilities under the ESA. petition with humans. A major oil spill sis whereverpossible. It is doubtful that Species are classified as either endan- from a tanker in the vicinity of the south- anyone anticipatedin 1973what alarge, gered or threatened. The ESA defines em seaotteris considered the most serious complex, and sometimes contentious endangered species as any species in threat (see Bonnell et al., this issue). job this would become. However, there danger of extinction throughout all or a Drowning in gill and trammel nets was a has been a continuing underlying significant portion of its range. Threat- significant cause of sea otter mortality in commitment throughout society and its ened species include any species likely the past until the Stateof Californiabanned various institutions that the goal of pro- to become endangered in the foresee- the use of these nets within the otter's tecting species is important forthe Nation. able future throughout all or a significant range (see Wendell, this issue). Under the ESA, the Secretary of portion of its range. A species is added the Interior, acting through the U.S. to the list when its survival is found to be Recovery Fish and Wildlife Service (FWS), over- threatened by one or more of the follow- Recovery, the ultimate purpose of sees the protection and conservation of ing factors: the present or threatened the endangered species program, is the fish, wildlife, and plants found to be in destruction, modification, or curtailment process by which the decline of an endan- seriousjeopardy. The Secretary of Com- of the species' habitat or range; gered or threatened species is arrested or merce, acting through the National overutilization for commercial, recre- reversed, or threats to its survival neutral- Marine Fisheries Service (NMFS), is ational, scientific,oreducationalpurposes; ized so that its long-term survival in nature given similar authority for most marine disease or predation; the inadequacy of can be ensured. This process requires the

28 Endangered Species UPDATE Vol. 13 No. 12 1996 implementation and to providecomments to facilitate coordination between groups. Such coordination allows the special lo- calknowledgeof affectedcommunitiesto be fully considered. This understanding can serve to reduce or eliminate human use conflicts with listed species and their habitats. The FWS recognizes that public support is vital to long-term survival and recovery of threatened and endangered species, and the public is invited to pro- vide comments on draft recovery plans. The revised recovery plan was drafted by the SSORT. Leading the team is Dr. Douglas DeMaster, NMFS; Dr. David Duggins, University of Washington; Dr. James Estes, National Biological Survey; Dr. Michael Martin, California Depart- Photograph by Jeff Foott ment of Fish and Game; Dr. Katherine maintenance of secure, self-sustaining minimize the risk of tanker accidents and Ralls, NationalZoologicalPark;Dr. Calos wild populations of species with the rnini- minimize the possible effects of oil spills. Robles, California State University, Los mum necessary investment of resources. Establishing one or more sea otter colo- Angeles; Dr. Ulysses Seal, Veterans Ad- The primary objectives of the recovery nies outside their present range was ministration Medical Center; and Dr. program, while working in close coopera- identified as the primary task since popu- Donald Siniff, University of Minnesota. tion with our partners, are to: (1) identify lation growth was minimal. In the Carl Benz from the FWS's Ventura Field those ecosystems and speciesthat face the mid-198Os, however, federal and state Office serves as the SSORT's Executive highest degree of threats; (2) determine biologists determined that the accidental Secretary. The SSORT also received tasks necessary to reduce or eliminate the entanglement and drowning of sea otters assistance from technical consultants, threats; (3) apply the limited resources in gill and trammel nets was the likely experts in science, and representatives available to the highest priority recovery factor limiting population growth. Since from other federal and state agencies and tasks; and (4) reclassify and delist species then the state of Californiahas effectively non-government interests, among them, as appropriate. restricted within sea otter habitat the use environmental groups, fishing interests, The first step in the recovery process of nets that accidentally drown sea otters, and the oil industry. In addition, the FWS is to initiate recovery actions needed to and population growth has subsequently held public hearings on the revised plan to stop the species' decline. At the same resumed. In 1989,the FWS reconstituted solicit additional comments. time, species-specific recovery goals are the Southern Sea Otter Recovery Team The tools available for recovery of developed and species information and (SSORT) and requested the team to re- listed species are numerous and may in- management needs are identified and view and recommend changes to the clude reintroduction of species into ranked in terms of their relative impor- existing recovery plan. In 1996, the formerly occupied habitat, land acquisi- tance. This information is typically set FWS released a draft revised recovery tion, captive propagation, habitat forth in a recovery plan. A recovery plan plan for public review (cited in this restoration and protection, population as- delineates, justifies, and schedules the issue as US Fish and Wildlife Service sessments,research, law enforcement, and research and management actions neces- 1996). The main objective of this re- technical assistance for landowners and sary to support recovery of the species, vised plan is to "passively allow" the public education. These efforts must al- including those that are likely to permit currently increasing sea otter popula- low time for an endangered species to the reclassificationor delisting of the spe- tion to continue to grow to a size that respond biologically to the activities and cies. These plans are comprehensive otters will likely persist following any protective efforts implemented on its be- documents that identify all known recov- natural or human-caused disturbance half. Recovery activities conducted by ery actions for a species and associated (see Benz, Recovery Plan, this issue). theFWS and its partners include: defining costs by all cooperating partners. They Coordination among federal, state, threats through research on biological re- serve as blueprints for private, federal, and local agencies, conservation organi- quirements, managing threats through and state cooperation in the implementa- zations, appropriate experts, and major habitat protection and restoration, and tion of recovery actions. land users is a key ingredient for effec- achieving a stable or upward population A recovery plan for the southern sea tively implementing a recovery program. trend for an endangered species. otter was developed and finalized by the The recovery planning process is designed Development and implementation FWS in 1982. This plan identified as the to allow potentially affected segments of of a translocation plan was considered primary management actions the need to the public to participate in planning and one of the FWS's primary recovery tasks

Vol. 13 No. 12 1996 Endangered Species UPDATE 29 in the 1982 southern sea otter recovery wound, kill, trap, capture, or collect, or ments with states that establish and plan. By establishing a second breeding attempt to engage in such conduct." maintain a program for the conserva- colony of sea otters into unoccupied Also prohibited by section 9 is the trans- tion of endangered and threatened habitat within their historic range, the portation and sale of protected wildlife species. Under section 6, the FWS FWS's goal was to reduce the probabil- and the importation or exportation of provides 75 percent of project funds (90 ity that more than a small portion of the any listed endangered species or prod- percent when two or more states coop- otter population could be decimated by ucts derived from them. erate on the same species) that can be a single natural or human-caused disas- There is a significant legal distinc- used for tasks covering all phases of ter. Translocation and subsequent tion between threatened and endangered ESA implementation, from candidate management actions required Congress species with respect to the ESA's prohi- conservation to recovery and delisting. to broaden the FWS's authority. Pub. bitions. This difference provides a Although chiefly a federal undertaking, Law 99-625 was enacted in 1986 allow- measure of administrative flexibility. the sea otter translocation was accom- ing the FWS to develop and implement The ESA's general prohibitions are ap- plishedunder State of Californiapermits a translocation plan. This law required plied by statute for endangered species as well as federal permits and with the the FWS to establish a management but not for threatened species. ESA assistance of biologists and law en- zone surrounding the translocation zone. section 4(d), however, requires the issu- forcement personnel from both the Any sea otters found in this manage- ance of regulations deemed necessary FWS and the California Department ment zone were to be removed using and advisable to provide for the conser- of Fish and Game. non-lethal means and returned either to vation of threatened species. the translocation zone or the range of Regulations may be as restrictive as the Conclusion the parent population. In addition, any section 9 prohibition for endangered As Mollie H. Beattie, former Di- sea otters found in the management species, or may be less restrictive if the rector of the FWS, said, "Our fate and zone would be considered to be a part of full range of protection is not believed that of our economy are linked to natu- an experimental population, and, as to be needed. ral systems. We cannot eliminate species such, would not be afforded the same The ESA provides for broad statu- and expect our own to survive. I would stringent protection as otters found in tory exceptions to the taking have liked to have stopped the ridicule the parent population. A total of 139 prohibitions. Provisions of section 7 about the conservation of snails, lichens, sea otters were translocated from cen- allow for the issuance of an incidental and fungi and instead move the debate tral California to San Nicolas Island in take statement to federal agencies, which to which ecosystems are the most re- the Channel Islands between 1987 and must identify measures to minimize the coverable and how we can save them, 1990 (see Benz, Attempts to Reintro- impact of incidental take on the species. making room for them and ourselves." duce, this issue). Section 10 outlines a permit process to The southern sea otter's struggle allow the FWS to grant the permits for for survival has helped raise public Ban on takings and other taking of listed species. These permits are awareness of the plight of endangered statutory prohibitions granted in accordance with the terms of an species in the United States and world- Once a species is officially listed as approved habitat conservation plan, and wide. The ESA obliges us to maintain endangered or threatened, it is given must meet a number of requirements to our commitment to conserve imperiled full legal protection under the ESA. mitigate effects on listed species. Taken species for the benefit of future genera- The ESA prohibits the import, export, together, these provisions are designed tions as well as our own. The ESA has or interstate or foreign sale of listed to allow economic development that been responsible for improving popula- animals and plants (including their parts will not "appreciably reduce the likeli- tions of declining species throughout and products) without a special permit. hood of the survival and recovery of the United States and has served as a Section 9 of the ESA prohibits specified species in the wild." model for international conservation acts which directly or indirectly harm efforts. Implementation of the ESA, by listed species. Unlike other major ESA Cooperation with the building stronger partnerships with provisions, section 9 restrictions apply statedterritories states, local governments, private in- not only to federal agencies and permit- State agencies often possess scien- dustry, and individuals; by exercising tees, but to all persons subject to United tific data and valuable expertise on the greater administrative flexibility to mini- States' jurisdiction. Also, the protec- status and distribution of endangered, mize socioeconomic effects; and by tion afforded to plants differs from the threatened, and candidate species. State reducing delay anduncertainty for states, protection extended to fish and wildlife, agencies, because of their authorities governments, private industry, and in- and provisions applicable to endangered and their close working relationships dividuals will preserve ecosystem health species differ from those applied to with local governments and landown- and sustainability into the future. threatened species. Section 9 of the Act ers, are in a unique position to assist the prohibits "taking" of endangered ani- FWS in implementing all aspects of the Jamie Rappaport Clark is Assistant Director for mals. Taking is defined to include ESA. Section 6 of the ESA authorizes Ecological Services with the U.S. Fish and "harass, harm, pursue, hunt, shoot, the FWS to enter into cooperative agree- Wildlife Service, Washington, D.C.20240.

30 Endangsred Species UPDATE Vol. 13 No. 12 1996 Evaluating Attempts to Reintroduce Sea Otters Along the California Coastline Carl Benz

The U.S. Fish and Wildlife Service The goals cited in the 1982 recov- Marine Mammal Protection Act (FWS) listed the southern sea otter, ery plan were to: (1) minimize the risk (MMPA) of 1972 (see Baur et al.; Enhydra lutris nereis, as threatened in of oil spills from tanker accidents and DeMaster et al., this issue). 1977 under the Endangered Species Act other sources; (2) establish at least one Translocations of listed species are of 1973 (ESA) after consideration of its additional breeding colony outside the authorized under the terms of section small population size, greatly reduced present range; (3) minimize vandalism, 10Q) of the ESA, which addresses the range, and the increasing risk from oil harassment and incidental take; (4) establishment of experimental popula- spills. The ESA requires the FWS to monitor recovery progress; and (5) inte- tions. However, prior to the amendments develop and implement recovery plans grate the recovery plan into plans of of 1988, there were no provisions under for listed species. The recovery plan for local coastal community governments. the MMPA to translocate sea otters for the southern sea otter was initiated in This paper reviews the events leading conservation purposes. To resolve this 1979 and approved in February 1982. up to the translocation, the process guid- dilemma, in 1986 Congress passed leg- During development of this plan, the ing it and the results. The success of islation (Pub. Law. 99-625) that Marine Mammal Commission recom- these efforts is also evaluated. specifically authorized and set the mended the FWS consider the ultimate ground rules for translocation of Cali- need for zonal management of sea otters Translocation as a recovery goal fornia sea otters. The key points were and fisheries in California (see Wendell, In 1982, the FWS considered oil that by regulation the FWS must de- this issue). Contemporary issues ad- spills as the primary threat to the contin- velop a translocation plan that includes dressed in the plan were the (1) ued existence of the sea otter. Although the following: (1) the number, age and taxonomic status of the Californiapopu- some management efforts were under- sex of sea otters to be translocated; (2) lation, (2) effects of sea otters on way to improve capture techniques and the methods for capture, translocation, shellfish fisheries, and (3) effects of rehabilitation of oiled sea otters, the release, monitoring, and protection; (3) outer continental shelf oil development, FWS believed that these tools alone the specification of a "translocation production, and transportation. would be ineffective in protecting the zone" where otters will be relocated, At the time the plan was being sea otter population in the event of a plus a buffer area, with formal section 7 developed, available information sug- large oil spill. The recovery plan also consultations (see Clark, this issue) re- gested that the sea otter population was recognized that the sea otter population quired in the zone for all Federal not growing, and some biologists be- had not significantly changed in size activities except those that are defense- lieved that the population was declining. since 1973. The California Department related; (4) the specification of a This information greatly influenced the of Fish and Game (CDFG) proposed "managementzone," which would sur- recommendation that translocating that the population was at carrying ca- round the translocation zone but would southern sea otters to a new site within pacity, which accounted for the reduced not include the existing sea otter range their historical range was necessary to growth rate (Miller 1980); the FWS or adjacent areas where expansion is enhance population growth and distri- suggested that the problem was due to needed for the species recovery; (5) bution. At the time the otter was listed, high mortality. Because the ability to measures to isolate and contain the ex- and when the recovery plan was ap- protect sea otters from oil once a spill perimental population, backed up by an proved, the magnitude of the threat to occurs is inadequate and the sea otter adequate funding mechanism; (6) a de- sea otters from incidental entanglement population was not increasing in size, tailed description of the relationship of and drowning in commercial halibut the FWS determined that translocating translocation to the status of the species gill and trammel nets was not recog- sea otters was the most effective and and to future section 7 determinations nized. It was not until later that an reasonable recovery action. The pur- relative to either the parent population analysis of data obtained between 1982 pose of translocation was to enhance or the experimental population; and (7) and 1984indicated that an average of 80 range expansion by establishing a new a provision that the plan should be ad- sea otters per year, or about 6 percent of colony within the historic range which ministered in cooperation with the state. the population per year, had been acci- would ultimately result in a larger con- The management zone is to be kept free dentally drownedin commercialfishing tinuous distribution and population size. of sea otters using non-lethal means, no nets. State and federal biologists con- Translocationwas viewed as paramount formal section 7 consultations will be cluded that these losses were large to achieving recovery and establishing required (only conferences), and inci- enough to have prevented the popula- a data base for identifying the optimal dental take of sea otters resulting from tion from growing from the early 1970s sustainable population level for the otherwise legal activities will not be a to the mid-1980s (Wendell et al. 1985). southern sea otter as required under the violation of the ESA or MMPA.

Vo1. 13 No. 12 1996 Endangered Species UPDATE 31 In June 1984, the FWS published a received during the public review pe- ties. The sea otter containment pro- Notice of Intent to prepare an Environ- riod and the final rule (50 C.F.R. Part gram, law enforcement, sea otter mental Impact Statement (EIS) and 17) that governed the translocation un- protection, review of Federal activities proposed rule for establishing an ex- der the new legislative authority (Pub. that may have affected the colony, and perimental population of southern sea Law 99-625). issuance of all permits related to the otters. All major interest groups, in- translocation was handled by the FWS's cluding environmental organizations, Implementing the translocation Fish and Wildlife Enhancement Pro- the oil industry, and sport and commer- Authority for implementing the gram. Assistance in translocation cial fisheries interests, were represented translocation was given to the FWS activities and subsequent research was at the public scoping meetings. As pursuant to Pub. Law 99-625. The FWS provided by the FWS's Research Group. suggested by the Council of Environ- requested and received assistance and The Research Group designed and mental Quality, the FWS established an cooperation from the CDFG for imple- conducted the translocation of sea ot- interagency project review team made mentation of the translocation plan. ters, including all aspects of capture, up of representatives from the CDFG, Under an existing Cooperative Agree- holding, veterinarian care, transport, re- Marine Mammal Commission,and Min- ment, the FWS and the CDFG signed a lease and baseline ecological studies. erals Management Service. Their Memorandum of Understanding ad- These studies were continued after the assistance was solicited to participate in dressing respective responsibilities, translocation and included an assess- the scoping process and consult with funding, contingency plans to handle ment of the effect(s) of translocation on the FWS in the preparation of the EIS. funding, containment and logistical the parent population. All meetings of the interagency project problems, and other items. The successful implementation of review team provided for the participa- The FWS had lead responsibility the translocation plan depended on an tion and involvement of interested for all management and research activi- adequate commitment of funding and members of the public. The FWS also established an Expert Re- view Team consisting of recognized experts in the fields of benthic ecology, marine mammal biology, marine resource econom- ics, physical oceanography, and the physics and chemistry of pol- lutant transport, to provide impartial comments to the FWS Polnt ~iioNue on major sections of the EIS. The draft EIS considered all data and information available up to the time of its publication and evaluated potential effects of the action on the marine environment, the southern sea otter, and the socioeconomics in the area. The draft EIS was made available for public review, and public hear- San Luis Obispo ings were held in Brookings, Oregon, and Monterey and Ventura, California. After release of the draft EIS, the President . . ... signed into effect on November 7, 1986 Pub. Law 99-625, which broadened the FWS's authoriza- tion for long-term management of 50 80km an experimental population. Therefore, the final EIS was pre- pared to meet the requirements of Pub. Law 99-625, which was the sole authority under which trans- location was proposed. The final Figure 1. The Channel Islands, roughly 70 miles (110 km) west of Los Angeles and significantly EIS also incorporated comments south of the current sea otter habitat, were chosen as the translocation site.

32 Endangered Species UPDATE Vol. 13 No. 12 1996 Category Year 1 Year 2 Year 3 Year 4 Years 5-9 TOTAL The lack of growth of the colony has been attributed primarily to poor

Total Captured 124 104 23 1 0 252 recruitment and, to a lesser extent, emi- gration and adult mortality. Although Released at Capture SO 43 8 0 0 101 reproduction has been observed every Died During Translocation 4 2 1 1 0 8 year, the fate of most pups is not known and few have been observed to be over Released During Translocation 13 0 0 0 4 135 days of age. Food resources are abundant and should be readily acces- Translocated to SNI 69 56 14 0 0 139 sible to young sea otters. Predation is Table 1. Summary of total number of sea otters captured for translocation to San Nicolas Island, August 1987-August 1996. not known as a factor, although great white sharks do occur in the area. Inci- personnel. The FWS requested funding duction, and containment techniques; dental take in the lobster fishery may through its normal congressional ap- (3) gather data on population dynamics, contribute to the lack of population propriations process. Federal funding ecological relationships of sea otters growth. Hundreds of pots are set around was administered through the FWS's and their near-shore community; and San Nicolas Island each season, and the Fish and Wildlife Enhancement Pro- (4) determine the effects on the donor opening into the pots may be large gram. Monies were distributed to population of removing sea otters for enough for a small to medium sized sea management and research. The CDFG translocation. otter to enter. Entrapment of sea otters received operational funds through the Reproduction at San Nicolas Island in lobster pots has not been documented ESA section 6 (grant-in-aid to states) was first observed during the initial trans- at San Nicolas Island. However, a dead program. location year, when two pups were sea otter was found near Santa Cruz, On August 11,1987, the FWS pub- observed. As of September 1996,40pups Santa Cruz County, in an abandoned lished a final rule (50 C.F.R. 17.84) to are known to have been born at San Nicolas crab pot with similar dimensions tothose establish an experimental population of Island, of which 6 died as pups, 11 were of lobster pots. A few records exist of the southern sea otter at San Nicolas weaned, and the fate of 23 remains unde- Alaskan sea otters entrapped in crab Island, located about 70 miles west of termined. Pre-weaning mortality within pots. With only five to six pups born Los Angeles (see Figure 1). The final the mainland population in California is each year and high pre-weaning mortal- ruleestablishedthe boundaries of atrans- about 40 percent. In past years, a higher ity, incidental take andnatural mortality location zone to which otters would be mortality rate (66%)has been documented factors could threaten the long-term per- translocated and given protection simi- at San Nicolas Island. This rate may be sistence of the population. lar to that of the source population, and misleadingly high because the number of a management zone to be maintained identifiable otters at the island has de- Zonal management otter-free by removing sea otters by clined due to tag loss, thus tracking The containment program is in- non-lethal means. The intent of desig- individual otters is almost impossible. tended to prevent sea otters from nating a management zone was to limit Of the 139 sea otters translocated colonizing the management zone sea otter impacts on existing fisheries to San Nicolas Island, the fate of 61 is through a cooperative effort between and other marine resources (see known. Thirty-seven sea otters are the FWS and the CDFG. The contain- Wendell, this issue). The management known to have returned at least once to ment operation, as outlined in the zone encompasses the entire southern the range of the parent population. translocation plan and the FWS's Con- California bight south of Point Concep- Eleven have been captured in the desig- tainment Plan, consists of three tion, except the translocation zone nated management zone and released in interrelated and interdependent activi- surrounding San Nicolas Island (see the range of the mainland population. ties: surveillance of the management Figure 2). Between 1987 and 1990,139 Three were found dead at San Nicolas zone, the capture of sea otters in the sea otters (31 males, 108 females; 63 Island shortly after they were released. management zone, and the relocation of adults, 76 juveniles) were translocated Three have been found dead in the man- captured sea otters to the range of the to San Nicolas Island from the main- agement zone. At least seven are mainland population. land population. No sea otters have believed to have taken up residency at Captured sea otters are released in been translocated to San Nicolas Island the island. The status of the remaining the northern portion of the mainland since 1990 (see Table 1). sea otters is unknown. The cause of the population range to reduce the likeli- continuing attrition of tagged animals hood of returning to the management Results of translocation efforts over the past several years remains un- zone. Early in the containment pro- The purposes of the translocation known. The question of the final fate of gram, sea otters captured in the program were to: (1) implement a pri- the original animals becomes less rel- management zone were released at their mary recovery action for a Federally evant as many of the translocated original capture location along the main- listedthreatenedspecies; (2) obtain data animals are reaching the expected natu- land. Travel time to the more remote for assessing capture, transport, reintro- ral lifespan of a sea otter in the wild. locations was lengthy; therefore, the

Vol. 13 No. 12 1996 Endangered Species UPDATE 33 FWS and CDFG decided to re- duce stress to captured sea otters by releasing them in accessible locations. To avoid releasing a disoriented female sea otter into an area that may contain aggres- sive male sea otters, the decision was made to release female sea otters into female dominated ar- eas. Male sea otters were released into male dominated areas. Since 1987,20independent seaotters (lomales, 10 females) and 4 dependent pups have been captured in the management zone. Eleven of the otters had been translocated to San Nicolas Island, four had apparently swam down from the mainland range, and tions are vulnerable to a variety of per- tively. The high count for the 1996 nine either swam down from the main- turbations. For the sea otter, the impact survey was 430 sea otters indicating land range or were born in the associated with oil spills was the great- that the population is established and management zone or at San Nicolas est threat, and there were increasing should continue to grow. These obser- Island. Two of the sea otters mentioned risks of oil spills from expected in- vations suggest that post-translocation above were captured and removed from creases in offshore oil and gas dispersal of sea otters occurs and can the management zone twice. development and from increases in reduce the population to a very small In February 1993, all sea otter con- coastal tanker traffic. Recovery of the founder population. However, if left tainment activities were halted following sea otter also would most likely conflict undisturbed and protected, the founder the deaths of 2 independent otters shortly with both shellfish fisheries and oil re- population can become established. The after their release at a predetermined lated activities. Consequently, major differences between the Wash- site at the northern end of the range. implementation of the translocation ef- ington population and the San Nicolas Concern was raised whether sea otter fort involved diverse political attention Island population are the active lobster containment activities were being con- and a highly regulated process. trap fishery at the island and the pres- ducted by non-lethal means. An By the end of the first year of trans- ence of the management zone. Although evaluation of containment techniques location, the rate of dispersal of sea sea otters found within the management proved to be inconclusive, and recom- otters from the island was higher than zone were to be removed, as many were, mendations were made to continue sea expected and appeared problematic to there are no data suggesting that sea otter containment activities with minor establishing a colony. However, a re- otter containment activities create a sink modifications that included improved view of another reintroduction effort, effect on the island population. The post-release monitoring activities. How- that to Washington State, provided in- dynamics of the management zone sur- ever, subsequent sea otter containment sight that translocation to San Nicolas rounding San Nicolas Island is not activities were limited due to the un- Island may ultimately be successful. believed to negate a comparison to the availability of funds within both the For the Washington effort, 59 Alaskan Washington State example. FWS and the CDFG. No sea otters have sea otters were released during 1969 At the end of the third year of the been removed from the management and 1970. At least 16 of 29 sea otters post translocation phase of the program zone since early 1993. released in 1969 died within 2 weeks. (August 1993), the FWS evaluated the No data are available on deaths after the status of the translocated San Nicolas Evaluation of the success of the second release of 30 sea otters in 1970. colony, containment efforts and failure translocation effort Very few data on this reintroduction criteria. Population surveys confirmed From 1980 until the initial translo- were recorded until 1977, when FWS that the numbers of sea otters were cation period, the southern sea otter biologists conducted the first intensive continually declining, and therefore, the recovery program was considered a high survey. At that time only 19 sea otters, program as a whole should be evalu- priority FWS program based upon the including 4 pups, were observed. How- ated. The FWS could not identify any combination of species vulnerability and ever, population surveys during the deterministic causes as to why the San political controversy associated with re- 1980s suggested that the Washington Nicolas Island colony was not increas- covery needs. The southern sea otter population was slowly increasing. To- ing as expected, and therefore took a population size was small and growth tal counts in 1981, 1983, 1985, and "wait and see" position while continu- was minimal, at best. Small popula- 1987 were 36, 52, 65, and 94, respec- ing monitoring efforts.

34 Endangered Species UPDATE Vo1. 13 No. 12 1996 and recovery needs grew. The restric- tions on entangle net fishing virtually eliminated the accidental drowning of sea otters, and growth of the mainland population resumed. The ability to es- tablish a colony was proving to be difficult and the translocation effort was expensive. Furthermore, the Exxon Valdez oil spill in 1989 demonstrated that oil spills can affect a large area, the effects of which can persist over a pro- longed period, and the ability to protect sea otters once a spill occurs is insignificant. In combination, these changing conditions affected the FWS's focus and priority on the translocation effort. The purpose of the translocation initially was to establish a sea otter colony and to Sea otter being capturedfor translocation to San Nlcolas Island. Photograph provided by Carl Benz, U.S. Fish and Wildlife Service. obtain information valued for the long- term management of sea otters. As Over subsequent years, bi-monthly Lessons from the translocation evidencegrew indicating that the colony sea otter counts at San Nicolas Island The political and public scrutiny of would not easily become established, ranged between 12-16 independent ot- daily events, often resulted in a "small most consideration seemed to shift away ters. The population has not changed picture" mentality focusing attention on from the success of the entire project. significantly in size. A small colony issues that in the "big picture" were In light of our present understanding of (12-16 individuals) of southern sea ot- insignificant. The deaths of three ani- the recovery needs for the southern sea ters still persists at San Nicolas Island. mals translocated to the island, the ability otter, including an analysis of oil spill Based on the results of the translocation to track animals that disperse from the risk to coastal California and the main- effort in Washington State, additional island, and the fate of missing animals land population growth rate, it appears years of monitoring are necessary to are examples that required extensive that recovery will likely be achieved by determine if the San Nicolas Island attention by the FWS (briefing comrnis- the natural growth of the mainland popu- colony will become established. sions, drafting reports, etc.). This lation and the San Nicolas Island colony From a management perspective, attention tended to discredit the pro- will not contribute significantly. Atten- the translocation as implemented failed gram, compromising the public's tion and efforts therefore have shifted to to achieve the anticipated results for understanding and support. In turn, this other higher priority needs, with only expediting recovery. As discussed in influenced decisions on how the trans- minimal attention remaining at San the EIS, the FWS expected that most of location efforts would proceed. In the Nicolas Island. the sea otters would remain at the island big picture, and over time, these issues and the colony would become estab- were not significant, but the impacts on Literature Cited lished in about 5 years. Carrying the program were. Miller, D.J. 1980. The sea otter in California. capacity was expected to be reached As the translocation program ad- Pages 79-81 in The California cooperative oceanic fish investigation report. Volume XXI. after a minimum of about 10 to 15years. vanced, the political-environmental Wendell, F.E., R.A. Hardy, and J.A. Ames. 1985. Actual implementation of the trans- conditions changed. The FWS faced ever Assessment of the accidental take of sea otters, location plan was significantly increasing budget demands to list and Enhydra lutris, in gill and trammel nets. Marine hampered because any change to trans- recover endangered species, the number ResearchBranch,CaliforniaDepartment of Fish and Game. 30 pp. location procedures required a change of listed species more than doubled be- in the enacting federal regulation and tween 1980 and 1990. The amount of concurrence by the Califomia Fish and recovery dollars available did not keep Game Commission. At times this pro- pace with recovery need. New high- cess exceeded 6 months. The profde controversies of a much broader requirement of Pub. Law 99-625 that scale surfaceddemandingattention by the the fine procedural details be defined in FWS (e.g., spotted owl, delta smelt, Cali- federal regulation prohibited the FWS fornia gnatcatcher). The CDFG was from efficiently, and therefore possibly experiencing similar problems. more effectively, implementing the Carl Benz is the Assistant Field Supervisor- At the same time, our knowledge Endangered Species Listing and Recovev, with the translocation. base regarding the southern sea otter U.S. Fish and Wildlife Senice in Ventura, CA.

Endangered Species UPDATE 35 The Second Southern Sea Otter Recovery Plan Carl Benz

The original recovery plan for the The Recovery Team's approach vided are equivocal. The FWS in deter- southern sea otter (Enhydra lutris nereis) Because the likelihood of sea otters mining a course of action to recover the was developed and approved by the persisting in California is currently de- southern sea otter, therefore, used as its U.S. Fish and Wildlife Service (FWS) termined primarily by whether or not a standard a "preponderanceof evidence" in 1982. This plan identified the need to major oil spill occurs within the otter's rather than the standards normally ap- minimize the risk of tanker accidents, range, two approaches have been iden- plied in publishing scientific literature. but recognizing the inevitable possibil- tified that would lead to delisting the ity of an oil spill, it also recognized the southern sea otter under the ESA: (1) Assumptions need to minimize oil spill effects. The increasing the range of otters in Califor- The southern sea otter population primary recovery method outlined was nia to reduce the risk of a single oil spill was listed as threatened in 1977 because increasing the sea otter range to de- event reducing the otter population be- (1) its population size was small and dis- crease the probability that a oil spill low a level that is viable, and (2) de- tribution limited, and (2) the remaining would impact a large percentage of the creasing the risk to otters that a major oil habitat and population was potentially sea otters' habitat. At that time popula- spill event will occur within their range. jeopardized by oil spills, pollution, and tion growth was minimal and transloca- In developing criteria to delist under the competition with humans (42 Federal tion was considered necessary to ESA, the SSORT used an approach that Register 2965). A major spill of oil from expedite range expansion and popula- incorporates elements of population vi- a tanker in the waters in the vicinity of the tion growth. ability analyses, which, when applied to range of the southern sea otter is still The original recovery plan did not this population of sea otters, required consideredthemost seriouspotential threat quantify criteria for delisting. The stated information on the probability of an oil to the species. Approximately six spills objective was to restore the southern spill occurring within the range of the greater than 1,000 barrels that are likely to sea otter to a non-threatened status and southern sea otter, the likelihood of a impact the southern sea otter have been to maintain this population at its opti- spill of a particular size occurring, and estimated to occur over the next 30 years mum sustainable level. Optimum sus- the expected level of mortality associ- (see Bonnell et al., this issue). The ex- tainable population (OSP) level for the ated with an oil spill event of a particu- pected number of otters that will die as a southern sea otter was considered to be lar size. The FWS responded to the result of contact with oil following a spill a population size and distribution greater SSORT1srequest to contract experts to is likely to be no less than 50 percent. than the listing threshold under the En- provide this information (U.S. Fish and Rehabilitation of oiled sea otters is expen- dangered Species Act (ESA). In the Wildlife Service 1996, Appendix B and sive, may be detrimental to some indi- original recovery plan, the FWS recom- C; see Bonnell et al., this issue). The viduals, and is of questionable benefit to mended that delisting be considered SSORT acknowledges that the datapro- the population (Estes 1991). when the population is stable or in- creasing at sustainable rates in a large enough area of their original habitat that only a small proportion of the popula- tion would be decimated by any single natural or man-caused catastrophe. In 1989, the FWS established a Southern Sea Otter Recovery Team (SSORT) and requested that the they review the 1982 plan, determine if it still satisfactorily addressed the recov- ery needs for the southern sea otter, and decide whether the plan should be up- dated or revised. The SSORT recom- mended revision. In 1993, the FWS established a team of Technical Con- sultants (representatives from State agencies, environmental organizations, commercial and recreational fishing interests, and the oil industry) to pro- vide information and comments to the SSORT. Photograph by Jeff Foott

36 Endangered Species UPDATE Vo1. 13 No. 12 1996 The 1982 recovery plan identified The minimum population size that effects of an oil spill on the otter popu- the need to establish by translocation can be considered viable is one that is lation, in the event that one occurs; (3) one or more colonies to enhance range large enough to accommodate adaptive develop and implement plans to reduce expansion. Three major events have changes and allows the population to be or eliminate the incidental take of sea occurred subsequent to the transloca- resilient to changes in the environment. otters and other sources of take in Cali- tion efforts to establish a colony of A genetically effective population of fornia; and (4) evaluate assumptions southern sea otter at San Nicolas Island 500 (Franklin 1980) is considered ad- used to estimate the population level at which alter the need and rationale for equate such that the loss of genetic which southern sea otters could be con- that translocation plan. First, state re- variation due to small population size is sidered recovered under the ESA. strictions and closures on gill and tram- balanced by the gains of mutation. mel nets throughout the range of the However, the number of individuals in What's next southern sea otter has resulted in a sub- a population required to achieve a ge- The FWS announced the availabil- sequent resurgence in population growth netically effective population size of ity of a draft revised recovery plan for (see Wendell, this issue). Second, the 500 may be several times greater than the southern sea otter on June 26,1996. Alaskan Exxon Valdez oil spill of 1989 500 individual animals (Frankel and The public was invited to provide com- confirmed many of the worst fears about SoulC 1981). Until better information is ments on the draft revised plan. In addi- the consequences of such events. The available, the estimate that 27 percent tion, two public hearings were held in spill was uncontrollable and quickly of the census population reproduces, as Monterey, California on July 18,1996. spread over an area greatly exceeding proposed by Ralls et al. (1983), will The public comment period was the present range of the sea otter in be used. Therefore, an actual minimum opened for 90 days, closing on Sep- central California plus that of the trans- viable population of approximately tember 24, 1996. located colony at San Nicolas Island, 1,850sea otters are required to maintain Public and agency comments will and efforts to save and rehabilitate oiled a genetically effective population of be reviewed by the FWS. The SSORT sea otters were of little or no value to the 500. The SSORT proposed that this andTechnica1Consultants will be asked population (see Williams and Williams, number be used as the threshold popu- to review and address technical ques- this issue). Third, the translocation to lation level for endangered status. tions and comments. The SSORT will San Nicolas Island has been less suc- The population level at which ultimately be responsible for providing cessful than originally hoped in estab- delisting of the sea otter should occur the FWS with their recommendations lishing a viable population (see Benz, was based on the modeling efforts ref- for a final document. Scheduling of Attempts to Reintroduce, this issue). erenced earlier (see Bonnell et al., this meetings with the SSORT and Techni- Therefore, the current strategy for re- issue). As many as 800 southern sea cal Consultants, and completion of covering the southern sea otter popula- otters could contact oil following a the final Southern Sea Otter (Revised) tion is to increase the number of sea 250,000 barrel oil spill event in central Recovery Plan, depend upon FWS otters in California, such that following California. Because data are not avail- budget and priorities established for a major oil spill in the waters off central able to precisely predict the level of fiscal year 1997. California, the remaining otters will otter mortality which will occur, the constitute a surviving population. The FWS took a conservative approach and Literature Cited FWS recommends against additional assumed that all otters contacted by oil Estes, J.A. 1991. Catastrophes and conservation: translocation to accomplish the objec- within 2 1 days of a spill will die. There- lessons from sea otters and the Emon Valdez oil spill. Science 254: 1596. tive of increasing the range and number fore, to meet the standard that in the Frankel, O.H. and M.E.Soul6. 1981. Conserva- of southern sea otters. event of a major oil spill, the population tion and evolution. Cambridge University should not be reduced below the level of Press, Cambridge, United Kingdom. 327 pp. Overview of revised recovery plan 1,850, the southern sea otter population Franklin, I.A. 1980. Evolutionary changein small populations.Pages 135-150inM.E.SoulC and The current draft revised southern should not be delisted under the ESA B.A. Wilcox, editors. Conservation biology: sea otter recovery plan retains the same until the average population level over anevolutionaryecological perspective. Sinauer primary management actions,but it does a three year period exceeds 2,650. Associates, Sunderland, Massachusetts. not recommend translocation. Sea otter Based on the expected rate of popula- Ralls, K., R.L. Brownell, Jr., and J. Ballou. population growth and range expansion 1983. Genetic diversity in California sea tion growth (approximately 5 percent otters: theoretical considerations and man- will be passive, i.e., not augmented by per year), delisting under ESA could agement implications. Biological Conser- translocation. Delisting criteria have occur by 1999. vation 25209-232. also been identified: the southern sea The following are the primary tasks U.S. Fish and Wildlife Service. 1996. Southern sea otter recovery plan, 1996 draft. Ventura, otter population should be delisted un- identified in the draft revised recovery California. 41 pp. der the ESA when, based on standard plan: (1) monitor existing and translo- survey counts, the average population cated populations; (2) develop and level over a three year period exceeds implement a plan to reduce the prob- 2,650 animals (U.S. Fish and Wildlife ability of an oil spill occurring in the sea Carl Benz is the Assistant Field Supemisor- Endangered Species Listing and Recovery,with the Service 1996). otter range and a plan to minimize the U.S. Fish and Wildlife Service in Ventura, CA.

Vol. 13 No. 12 1996 Endangerecl Species UPDATE 37 Assessing the Threat of Oil Spills to Southern Sea Otters Michael L. Bonnell, R. Glenn Ford, and Allan J. Brody The California population of sea and barge accidents. Spills at oil pro- barrels have an occurrence rate of 0.13 per otters was listed as threatened under the duction platforms and pipelines are far billion bbls (Minerals Management Ser- Endangered Species Act in 1977 due to less likely to have a major impact on sea vice 1994; see Anderson and LaBelle its small size, isolated and limited geo- otters because of the location of plat- 1990). A reasonable approximation of graphic range, and vulnerability to oil forms in relation to the sea otter range and the quantity of oil and petroleum product spills (Federal Register 42:2965-2968). the typical pattern of winds and currents transported per year can be obtained from Today the population, although increas- along the coast. commodity flow statistics for waterborne ing slowly, is still small, and its range The magnitude of the threat can only commerce of the United States, devel- has not appreciably increased. Conse- be estimated as the probability of future oped by the U. S. Army Corps of Engi- quently, its vulnerability to oil spills events based on the occurrence of past neers, and import-export statistics com- remains high. events. To extrapolate from historical piled by the Bureau of the Census. Using The threat of oil spills to the Cali- data, the assumption must be made that these numbers, the total quantity of oil and fornia population has been underscored improvements in tanker safety, naviga- petroleum product transported into San in recent years by three vessel accidents tion, and construction are inconsequen- Francisco Bay or past the sea otter range with release of oil or bunker fuel that tial. This assumption is probably suspect; in 1989 was 450 million bbls (U. S. Coast had the potential of contacting sea ot- clearly such improvements should have a Guard 1996). Assuming that the same ters. These were a leaking barge towed beneficial effect andbeencouraged. How- volume is transported each year, the prc- south from San Francisco (the Apex ever, safety improvements may not be jectedquantity over 10 years is 4.5 billion Houston, February 1986), the explo- enough; given the sophisticated tracking/ bbls and, over 30 years, 13.5 billion bbls. sion of a tanker off San Francisco (the warning systems in place, the Emon Based on the history of oil spills in TNPuerto Rican, October 1984), and Valdez spill in Prince William Sound U. S. waters and the volume of oil and a barge taking on water off Cape San should never have occurred. petroleum product transported, we might Martin (the Spartan 120, May 1983). Historical data can be used to cred- expect at least one oil spill of 1,000 bbl or Additionally, there have been two near- ibly estimate the number and size of spills greater in the next 10 year period, and groundings of deep-draft vessels along that might occur over a given time period. three in the next 30 year period. These are the central California coast (the Sealift Although small spills occur much more minimumexpectations-kzause each oil Pacific in April 1984 and the TNAus- often than large ones, most are at marine spill is an independent event, the occur- tin in April 1980);both groundings were terminals during transfer of oil or refined rence of one oil spill does not diminish the narrowly averted after the vessels drifted product. Consequently, small spills are likelihood of subsequent spills. It should to within a few kilometers of the sea less likely to reach sea otters and, when be recognized that these spills could theo- otter range. they do, result in limited mortality. In retically occur anywhere along the tanker The Exxon Valdez oil spill clearly contrast, most spills from vessels at sea route. However, most spills off the Pa- demonstratedthesensitivity of seaotters are large (many thousands of gallons). cific coast in the last 30 years have oc- to oiling. Approximately 11,000,000 While the probability of such acci- curred close to land and particularly as gallons (42,000,000 liters) of crude oil dents is low, large spills along the open tankers make their approach to port (U. S. were released into Prince William Sound coast can have large impacts. Substantial Coast Guard 1996). when the vessel grounded in March threat to sea otters exists from all vessels 1989; subsequent winds carried oil in transit past the central California coast Modeling contact of sea otters by southwestward to contaminate waters due to quantities of bunker fuel. Tankers, oil spills off the Kenai and Alaska peninsulas which account for about 28% of all vessel Although we cannot be sure of when and Kodiak Island. Best estimates of traffic to or from ports in San Francisco or where oil spills will occur, we can use mortality range from 2,650 (Garrott et Bay, pose an exceptional threat; relative statistical models to examine their poten- al. 1993) to 3,905 sea otters (DeGange to other vessels, tanker spills may be five tial impact on the sea otter population. et al. 1994). time as large (U.S. Coast Guard 1996). This can be done by conducting many The California population of sea computer simulationsof oil spill events, otters has, thus far, escaped significant Learning from history with random selection of spill origin, impact by oil spills. However, most From analysis of tanker oil spills in size, and date, followed by examination researchers (including the authors) be- U.S. waters between 1974and 1989,ithas of the results. lieve that a spill is inevitable and there- been estimated that spills of 1,000 to In an analysis of potential impacts of fore planning a response is essential. 100,000barrels (bbls; 42 gallbbl) have an oil spills on the southern sea otter popula- Based on spills that have occurred, the occurrence rate of 0.19 per billion bbls tion for the U. S. Fish and Wildlife Service greatest threat to sea otters is from tanker transported, and spills greaterthan 100,000 (FWS), Ford and Bonnell(1995) simu-

38 Endangered Species UPDATE Vol. 13 No. 12 1996 cause a major and perhaps irrecoverable drifted, the less likely that oiled sea vival of captured oiled sea otters is impact on the sea otter population. otters would die. For nearly 300 sea representative of a population of oiled otters captured in rescue efforts follow- animals observed but not removed from Mortality of sea otters ing the spill, a survival rate was calcu- their contaminated habitat. It seems Given that a substantial number of lated as a function of the distance from likely that many sea otters left to their sea otters are contacted, what might be the spill origin to capture sites along the fate would additionally have become the mortality? This is a difficult ques- trajectory of oil. The survival rate func- oiled over time until they ultimately tion to answer because mortality of each tion provided a good fit with the data, died of toxic effects and hypothennia. individual sea otter is determined by the indicating that no sea otters would sur- Thus, estimates of mortality derived degree of oiling and this, in turn, is vive at the spill origin, about 50% would from the relationship should be viewed affected by the amount of oil in sea otter survive at a distance of 150 km, and as minimum values. It is also important habitat and how long it remains. Sea survival of sea otters at greater dis- to remember that these estimates are of otters may survive initial contact but tances would asymptotically approach mortality from direct contact with oil; succumb in following days due to re- 100%. should oil remain and degrade sea otter peated exposure to oil. Working in fa- This relationship presumed that sur- habitat, additional and long-lasting im- vor of sea otters is weathering of oil as it drifts, and the opportunity provided for clean-up and use of dispersants. Many factors influence direct mor- Worst Case Spill tality of sea otters once they are con- tacted by spilled oil. Oil is toxic to sea Simulation of 250,000 bbl otters in at least three distinct ways: spill beginning on lung damage from inhaled volatile com- March 4, 1991 ponents, gastrointestinal damage and perhaps systemic toxic effects from oil ingested while grooming, and hypoth- ermia following oiling of pelage. Sea otters dying from oiling may evince all three. However, the basic data needed to construct a mechanistic model of individual sea otter mortality during a spill, which would allow modeling of spill impacts "fromthe bottomup," sim- ply do not exist. One of the missed opportunities of the Exxon Valdez spill was that such data were not collected. In iedras Blancas the event of another spill affecting sea otters, such studies should receive high- est priority. The question of mortality has there- fore been addressed in perhaps the only way it can-with a statistical analysis. Using data collected following the Exxon Valdez spill, Brody et al. (1996) exam- ined the validity of the assumption that the overall toxicity of oil to sea otters should decrease as spilled oil ages, weathers, and spreads. As oil weathers, volatiles evaporate, caustics degrade, and the oil itself becomes diluted. In the absence of other data, they tested the assumption that distance from the spill origin to point of contact with indi- vidual sea otters might serve as a rea- Figure 2. Time-course of movement and spread of oil from the 100th ranking sonable surrogate for detailed data on simulation of a 250,000 bbl spill. This simulation resulted in the greatest number the state of oil and the degree of expo- of sea otters contacted out of 200 simulations at randomly selected sites withln 25 sure-the greater the distance that oil nml from land.

40 Endangered Species UPDATE Vo1. 13 No. 12 1996 pacts on the population may result. allowed it to move closer to shore. Con- southward. Oil not yet beached rounded Detailed scenarios were produced tact with sea otter habitat first occurred Point Conception by about day 20, and for the 100th and the 90th percentile six days following the release when oil slicks became increasingly fragmented contacts of a 250,000 bbl spill (about beached near Point Lobos. Oil contin- as oil drifted into the Santa Barbara the size of the Exxon Valdez) on the ued to enter sea otter habitat over the Channel. In this simulation, mortality California population. In each of these next three days under variable west and was about 37% of the spring 1992 simulations, 2,500 LEs were tracked to northwest winds to about 20 knots and population; in heavily contaminated por- determine distance of drift prior to con- resulted in heavy contaminationof near- tions of the coast from Point Lobos to tact with sea otters. The 100th percen- shore waters to about Pfeiffer Point. Point: Sur, the local population suffered tile spill contacted 1,820 sea otters of The main body of the slick resumed its mortality approaching 55%. which 777 ultimately would die using southward drift on day 9 after the spill Using the 90thpercentile worst case the relationship of Brody et al. (1996; under northwest winds of 20-30 knots, resulted in contact of 88 1 sea otters and, see Figure 2 and Table 1). Unfolding of sparing parts of the sea otter range be- using the relationship of Brody et al. the spill episode is illustrated by the tween Point Sur and Point Lopez. On (1996), resulting in mortality of 456 following time-course. The simulated day 12, south, southwest, and west winds animals. This spill originated about 36 spill occurred 36 km (19.5 nmi) west of of 20 knots or more again pushed oil km (19.5 nmi) northwest of Point Aiio Point Aiio Nuevo with oil driven by toward shore, initially resulting in heavy Nuevo. The simulated spill was driven real-time winds recorded from March 4 oiling of sea otter habitat near Point by real-time winds of August 11 through through 25, 1991. Over a three-week Piedras Blancas. Over the subsequent 3 1,1990. Initial contact with sea otters period, northwest winds were inter- four days, variable winds kept oil close in the vicinity of Point Aiio Nuevo oc- rupted repeatedly by the passage of to shore, first spreading northward to curred on the day after release. Over the storms. South and southwest winds as- Lopez Point and then southward to Point next two days, oil moved southward sociated with low-pressure cells slowed Sal. By day 17, northwest winds of 15- along the shore under northwest winds southward movement of the slick and 25 knots resumed and oil was driven of 15-20 knots. Four to five days fol- lowing the simulated spill, oil entered Monterey Bay resulting in heavy con- I Number I Mortality I Cumulative I C;;IJR~ Contacted Contacted tamination of near-shore waters in the 1, southern part of the Bay and then moved southward along the Big Sur coast to about Point Lobos. Five to six days after release, oil drifted south in acornpact 10 km wide slick contacting sea otters along the Monterey Peninsula to beyond Point Sur. Oil then moved 3-5 km offshore still remaining somewhat compact in the light winds and seas, and next con- tacted shore in the vicinity of Lopez Point about 13 days after the spill. Un- der the influence of variable winds from the south and west, oil continued to contact sea otter habitat from Lopez Point to near Point Piedras Blancas un- til about day 17, and thereafter drifted offshore leaving most of the range south of Point Piedras Blancas untouched.

Conclusions and recommendations Oil spills may be an unavoidable consequence of tanker transport of oil. Historical data suggest that it might be prudent to prepare for one or more spills of 1,000 to 100,000 bbls in the near future. Spills in this range can have a significant impact on the sea otter popu- Table 1. Number of see otters contacted and estimated mortali resaina- lation. How can the threat be reduced? from 100th percentile worst case scenario of a 250,000 bbl 41spill. The U. S. Coast Guard (1996) states that

Vol. 13 No. 12 1996 Endangered Species UPDATE 4 1 implementation of the Oil Pollution Act DeGange, A.R., A.M. Doroff, and D.H. Monson. Marine Mammal Science 9:343-359. of 1990 (OPA 90) regulations over the 1994. Experimental recovery of sea otter Minerals Management Service. 1994. Estimated carcasses at Kodiak Island, Alaska, following tanker spill occurrence rates of accidental oil next several years is expected to greatly the Exron Valdez oil spill. Marine Mammal spills, U. S. waters: 1974-1989. Draft Report reduce the probability of vessel casu- Science 10:492-496. by the Technical Analysis Group, Minerals alties and associated oil spills. Some Ecological Consulting, Inc. 1990. Seasonal and Management Service, U. S. Dept. of the lessening of the occurrence rate of oil annual trajectory analysis of simulate oil Interior, Washington, D.C. outflow from vessel routes offshore of the U. S. Coast Guard. 1996. Evaluation of oil tanker spills may indeed result; however, it California sea otter range. Prepared for the routing per Section 4111(b)(7) of the Oil would be unrealistic to hope that OPA U.S. Coast Guard by Ecological Consulting, Pollution Act of 1990. Report to Congress 90 regulations will eliminate all threat Inc., Portland, Oregon. 22 pp. prepared by the Department of Transportation, of large oil spills. Ford, R.G. and M.L. Bonnell. 1995. Potential U. S. Coast Guard, Office of Navigation Safety impacts of oil spills on the southern sea otter and Waterway Services, Washington, D. C. It appears unlikely that the U. S. population. Final Report prepared for the U. S. Coast Guard will achieve, in the near Fish and Wildlife Service, VenturaCalifornia, future and with concurrence of the In- by Ecological Consulting, Inc., Portland, ternational Maritime Organization, a Oregon. 42 pp. Ford, R.G. and J.L. Casey. 1985. Oil slick sizes and Michael L. Bonnell is a Research Associate with new Traffic Separation Scheme in and length of coastline affected: a literature survey the Institute of Marine Sciences at the University out of San Francisco Bay. Nor will a and statistical analysis. Final Report prepared of California, Santa Cruz, and Senior Scientist Shipping Fairway be established along for the Minerals Management Service, U. S. with Ecological Consulting, Inc., Portland, OR. the central California coast. However, Department of the Interior, by Ecological R. Glenn Ford is a Senior Scientist with Ecological Consulting, Inc., Portland, Oregon. 34 pp. Consulting, Inc., 2735 N. E. Weidler St., Portland, this does not mean that tankers must Garrott, R. A., L. L. Eberhardt, and D. M. Bum. OR97232. Allan J. Brody is aphysician affiliated take the most direct route. The Western 1993.Mortality of sea otters in Prince William with Stanford University Hospital and San Jose State Petroleum Association (WSPA; Sound following the Exxon Valdez oil spill. Medical Center. as cited in U. S. Coast Guard 1996) has recommended a stand-off distance of at least 50 nmi in agreement with the State of California. If adhered to by the oil companies and their tankers, this would result in a substantialdecrease in risk of oil spills to sea otters. Based on the results of Ford and Bonnell(1995) it is clear that a change in tanker routing would be the most effective way to reduce potential of impact of oil spills on southern sea otters. The recommended route (see Figure 3) skirts the edge of the one- percent contour for contact with the sea otter range (Ecological Consulting, Inc. 1990; see Saunders, this issue). Small, almost negligible, costs would be in- curred by tankers due to extra time at sea. These additional costs pale in com- parison to those incurred should a spill occur within these bounds. WSPA and oil companies do not have to wait for mandate from the U. S. Coast Guard- take initiative now and choose the route that best reduces the potential for im- pact on sea otters.

Literature Cited Anderson, C.M. andR.P. LaBelle. 1990. Estimated occurrence rates for analysis of accidental oil spills on the U. S. Outer Continental Shelf. Oil and Chemical Pollution 6:21-35. Brody, A.J., K. Ralls, and D.B. Siniff. 1996. Potential impacts of oil spills on Cahfornia sea otters: Implications of the Exxon Valdez in Alaska. Marine Mammal Science 12:38-53. Figure 3. Suggested changes to tanker routes around sea otter habitat.

42 Endangered Species UPDATE Vol. 13 No. 12 1996 Does 'Sanctuary' Mean Secure? - Rachel T. Saunders -

The Monterey Bay National Ma- however, while sanctuaries do recog- It's not what you see, it's what rine Sanctuary off central California is nize the contribution of marine re- you don't the only U.S. marine sanctuary that has sources to the economic vitality of Given the well-documented vul- a naturally occurring population of sea coastal communities, their use must nerability of sea otters to oil, the otters. Indeed, it is in these waters that be compatible with the program's pri- sanctuary's prohibition of offshore oil the California sea otter made its ac- mary goal of resource protection. and gas activities provides California's claimed comeback from near extinc- Human activities that would harm threatened sea otter population with tion. Today, the sanctuary continues to sanctuary resources are regulated. an important measure of protection. serve as the sea otters' life-support sys- Taken together with the adoption of tem, while the well-being of the otter Closing the door to oil drilling the most comprehensive boundaries serves as an important indicator of the The core of the sanctuary designa- for the sanctuary (encompassing more sanctuary's health. tion process is the issuance and review than 5,300 square miles), California The creation of the Monterey Bay of the Draft Environmental Impact State- sea otters are now protected from this National Marine Sanctuary in 1992 was ment and Draft Management Plan. Much threat throughout most of their range. the culmination of more than 15 years of the discussion is focused on sorting Only through an act of Congress would of unwavering public support and tire- out questions regarding the compatibil- the specter of oil rigs again loom on less efforts of government officials and ity of existing and future uses and pro- the horizon of this special area. environmental groups to provide one of tection of sanctuary resources. In some Additional sanctuary-imposedsafe- this nation's most beautiful and bounti- cases this tug-of-war over issues has guards include a prohibition on the es- ful marine areas with a special and long- seriously stalled the designation pro- tablishment of new dump sites for the lasting level of protection. cess. In 1983, the Reagan Administra- disposal of dredged materials within But what does it really mean to give tion published a notice declaring that sanctuary boundaries and a prohibition 'sanctuary' to a part of the ocean? Per- Monterey Bay was to be removed from on the discharge of prirnary-treated sew- haps most importantly it is an act of the list of active sanctuary candidates age. A sanctuary permit is required for foresight, a recognition of the value of (48 Federal Register 56253). This activities such as (1) the discharge or our marine heritage, and an acknowl- prompted an intense campaign to deposit of materials (except those inci- edgment that we have an obligation to counter the sanctuary's abrupt dental to routine fishing and vessel op- maintain these public waters, like pub- delisting, which many viewed as an erations); (2) the moving, removing or lic lands, for future generations. orchestrated attempt to prepare the injuring of a sanctuary historical re- The National Marine Sanctuary area for the oil-drilling auction block. source; (3) alteration of the seabed program is a unique federal program With the backing and activism of en- (except routine anchoring, fishing, created in 1972 to protect entire ma- vironmental organizations and local navigation or other harbor mainte- rine ecosystems, rather than individual governments in 1988, former Con- nance activities); (4) "taking" of ma- components such as fish or marine gressman Leon Panetta pushed rine mammals, sea turtles, or seabirds mammals. The aim is to safeguard through legislation requiring sanctu- (except as permitted under existing healthy marine environments, rather ary designation no later than Decem- federal wildlife laws); (5) the opera- than restore damaged ones. Adminis- ber 3 1,1989 (Pub. Law 100-627, sec- tion of motorized aircraft below 1,000 tered by the Department of tion 205). While this congressional feet in certain areas; and (6) possession Commerce's National Oceanic and At- mandate got the designation process of any historical resource, marine mam- mospheric Administration (NOAA), back on track, it was repeatedly de- mal, sea turtle, or seabird. Permits sanctuaries are managed through an layed due to the continuing contro- granted under local, state or other fed- integrated approach of enhanced re- versy over proposed oil and gas ac- eral authorities prior to sanctuary des- source protection, scientific research, tivities. Ultimately it was the outpour- ignation still stand, although NOAA and public education efforts. While ing of public support for the sanctuary does have the authority to make them the word sanctuary is associated with that sent a message that political lead- more protective of the sanctuary. Any a place of refuge, national marine sanc- ers could not ignore. A comprehen- new permits, granted by local, state, or tuaries are developed with the pur- sive ban on offshore oil and gas ac- other federal authorities after sanctu- pose of achieving conservation while tivities was eventually supported by ary designation must be reviewed by still allowing human uses. "Sanctu- the Bush Administration and included the sanctuary program and comply ary" does not mean that we remove by NOAA in the sanctuary's final regu- with terms and conditions necessary ourselves from the system, but that we lations. to protect sanctuary resources (U.S. honor the life within it. Importantly, Department of Commerce 1992).

Vol. 13 No. 12 1996 Endangered Species UPDATE 43 A court decision in the spring of and other potentially harmful activi- as potent reminders that an ounce of 1995 upheld a sanctuary regulation ties within its boundaries, at this point prevention is worth a pound of cure. limiting the operation of motorized it does little to directly elevate the Yet despite public outcry and con- personal watercraft (e.g., jet skis) protection needed from vessel-related cerns raised by environmental organi- within the Monterey Bay National oil spills, and point and non-point zations and government agencies such Marine Sanctuary (Personal Water- source pollution. as the California Coastal Commis- craft Industrv Association: A. Mason Most troubling is the sanctuary's sion, no immediate measures were put Killebrew. Jr: Derek Coppersmith. v. failure to put forth specific regula- forth as part of the Monterey Bay Department of Commerce. National tions to keep oil tanker and barge National Marine Sanctuary designa- Oceanic and Atmospheric Adminis- traffic further away from sensitive ar- tion or its management plan to control tration, U.S. Court of Appeals, March eas, sea otters, and other living re- the thousands of vessels which pass 3, 1995). This regulation designates sources of the sanctuary. The devas- through and near the sanctuary annu- four zones and access routes for the tating impacts of the Exxon Valdez ally. As a result of citizen and envi- operation of these craft. As noted in the spill-and the array of spills and close ronmental group advocacy, the U.S. court's decision, the intention of the calls along the California coast and Congress did require NOAA and the regulation is to provide enhanced re- elsewhere in the world-should serve U.S. Coast Guard to prepare a report, source protection by prohibiting operation of motorized personal watercraft in areas of high marine mammal and seabird concentra- tions, kelp forest ar- eas, rivermouths, es- tuaries, lagoons and other similar areas where sensitivemarine resources are concen- trated and most vul- nerable to disturbance and other injury from personal watercraft. The court found that NOAA was acting Gulf of the Farallones well within its author- ity in setting down rules for the sanctuary that it determined were necessary and reason- able and that the record amply supported NOAA's judgement on this issue.

The coast is still not clear Although the comprehensive boundaries and man- agement plan adopted National Marine Sanctuaries for the sanctuary pro- vide meaningful protection against ..----..------threats from offshore oil drilling, large-scale Figure 1. Boundary for proposed area to be avoided (ATBA). dumping proposals within its borders,

44 Endangered Species UPDATE Vol. 13 No. 12 1996 within 18 months from the time of the tuary Advisory Council, and from in- Coast). It has also engaged in a tug- site's designation, evaluating measures dividuals within the U.S. Coast Guard of-war with NOAA over the strength needed to regulate vessel traffic (Pub. and maritime shipping industry. How- of recommendations to be contained Law 102-587). Despite the congres- ever, the U. S. Coast Guard continues in the congressionally-mandated re- sional mandate, the report has still not to fail in its responsibility to make a port on vessel traffic within the sanc- been released as of January 1, 1997. determination about oil spill preven- tuary. This struggle and the resulting Meanwhile, the threat of a tanker and tion for the region. It steadfastly re- wall of delay in the report's release barge spill remains (see Bonnell et al., fused to recommend oil tanker buffer cannot bode well for resource protec- this issue). zones in its recent report Evaluation tion. The fact remains, however, that In 1994 the Center for Marine of Oil Tanker Routing (U.S. Coast oil spill prevention and natural re- Conservation released its own inde- Guard 1996), despite information con- source protection should be at the fore- pendent analysis of vessel traffic oil tained in the report that shows that front of vessel traffic management. spill risks and possible solutions. Safe this region has environmental sensi- New efforts to prevent oil spills in or Passage: Preventing Oil Spills in Our tivity equal to or greater than two near sanctuaries must be taken; once Marine Sanctuaries (Townsend and other sanctuaries that now have buffer the oil hits the water, the battle has Glazer 1994) sets forth ten detailed zones (southern California's Channel been lost. Until meaningful measures recommendations which, taken to- Islands and Washington's Olympic are in place, the coast cannot be con- gether, seek to: (1) create a management regime that includes areas to be avoided (ATBA) that keep vessels further off- shore, providing more time for re- sponse vessels to reach a disabled Proposed TSS ship before it drifts ashore and/or giv- ing spill responders time to mobilize vessels and other equipment in the event of a spill (see Figure 1); (2) lessen the risks posed by vessels approaching San Francisco by em- ploying a new traffic separation scheme that has all vessels using a common point outside of the ATBA as a staging area when entering or leaving the San Francisco Bay Area (see Figure 2), in an effort to mini- mize collisions and maximize the dis- National tance from the mainland and island Marine Sanctuaries hazards; (3) establish a means to respond 0 15 30 quickly to aid a disabled vessel and NauCcal Miles control its movements by strategically stationing rescue vessels with emer- gency towing capability; and (4) improve tracking of vessel move- ments by upgrading radar monitoring Existing TSS capabilities, employing state-of-the- art surveillance technology and other information gathering programs and giving vessel traffic managers more authority to track and direct vessel movements within San Francisco Bay and in the approaches to the Bay. The recommendations presented in Safe Passage have generated much discussion and have garnered support from congressional members, the Figure 2. Proposed new traffic separation scheme (TSS) for vessels Monterey Bay National Marine Sanc- approaching and departing the San Francisco Bay Area.

Vol. 13 No. 12 1996 sidered clear for the recovering Cali- Conclusions and mutual concern, as the sanctuary is fornia sea otter population or the other recommendations still in the early stages of constructing living resources of the Monterey Bay It is clear that while drawing a and implementing a more comprehen- National Marine Sanctuary. boundary line on a map and proclaim- sive enforcement plan. ing an area a sanctuary is an essential Sanctuary designation marked the Pollutants don't respect first step, boundaries alone do not beginning-not the end-of a long- sanctuary boundaries guarantee protection. Management term commitment to conserve and ef- Clean water is the sanctuary's life and regulation of potentially detri- fectively manage a world-class re- support system. Aside from oil spills, mental activities are also vital. source. It is a work in progress. Ensur- inadequately treated sewage and in- Today, as throughout the desig- ing a truly protected future will re- dustrial discharges, storm drain over- nation process, the sanctuary has been quire that all of us who use and enjoy flows, and pesticide runoff can also a focal point for important issues and sanctuary waters continue to carry the compromise the sanctuary. Sanctu- healthy debate on the management of sanctuary torch, stay involved, and ary activists advocated an active role our coastal and marine resources. speak out. As Brooks (1985) once for sanctuary management in protect- However, if the sanctuary is to be held said about Rachel Carson, we must be ing water quality. However, at the up as a model for marine conserva- "stonemasons who never lose sight of completion of the designation pro- tion, existing weaknesses in the sanc- the cathedral." cess, the State of California had re- tuary plan will need to be addressed. tained prime authority on most water Crucial to protection of the sanctuary Literature Cited quality issues. and the recovery of California's threat- Brooks, P. 1985. Rachel Carson at work: the Moreover, a 71 square nautical ened sea otters is the creation and house of life. G. K. Hall and Company, Boston, Massachusetts. mile area near San Francisco was also enforcement of tangible oil spill pre- National Oceanic and Atmospheric Administration. excised out of the sanctuary, poten- vention policies. Given that a large 1993.48 Federal Register 56253. tially weakening the sanctuary's con- proportion of the existing sea otter Personal Watercraft Industry Association; A. trol over activities within it (such as population is located within the bound- Mason Killebrew, Jr; Derek Coppersmith. v. Department of Commerce, National high volume discharges from the San aries of the sanctuary and that vessel- Oceanic and Atmospheric Administration. Francisco outfall). related oil spills remain a threat, it is March 3, 1995, U.S. Court of Appeals. Thus far it does appear that the incumbent upon the U.S. Fish and Townsend, R. and M. Glazer. 1994. Safe sanctuary program has forged pro- Wildlife Service (FWS) to immedi- passage: preventing oil spills in our marine sanctuaries. Center for Marine Conservation. ductive working relationships with ately start working with the sanctuary U.S. Department of Commerce. 1992. Final existing state and federal water qual- program, the U.S. Coast Guard, and Environmental Impact Statement and ity agencies and has effectively sanctuary advocates to secure these Management Plan for the Proposed Monterey weighed in on behalf of sanctuary long-overdue protections. Specifi- Bay National Marine Sanctuary. U.S. Coast Guard. 1996. Evaluation of oil resources. The sanctuary has also cally, the FWS should: tanker routing per Section 4 1 11 (b)(7) of the taken a promising, proactive posture (1) provide a rigorous review and Oil Pollution Act of 1990. Report to in initiating a comprehensive water critique of the congressionally-man- Congress, prepared by Department of quality protection program for the dated U.S. Coast Guard report on re- Transportation, U.S. Coast Guard, Office of Navigation Safety and Waterway Services, sanctuary and its watersheds. The ducing the spill threat to sanctuary Washington, D.C. Monterey Bay National Marine resources; Sanctuary's Water Quality Protection (2) request that public hearings be Program is leading a core group of held on the report within each county over two dozen representatives of adjoining the sanctuary so that report public and private agencies and orga- findings may be presented and public nizations at the federal, state, and lo- comments made; cal level in examining water quality (3) request the U.S. Coast Guard to problems and designing and imple- provide a timeline for implementa- menting conservation strategies. tion of tangible oil spill prevention These strategies will address issues measures (such as those identified in Rachel Saunders directs the Center for Marine such as urban runoff, marina and boat- the Center's Safe Passage report); and Conservation's Pacific Ecoystems Protection ing activities, and point-source pollu- (4) support the adoption of a spe- Program. The Center is a national, non-profit cific buffer area large enough to ad- organization, which, since 1972, has focused on tion. The Program has also initiated conserving the diversity and abundance of life in the development of a regionally con- equately protect sea otters and other theoceans. She holds anM.S, inNatural Resource sistent water quality data base and a sanctuary resources. The FWS would Policy and Management from the University of regional monitoring program, and is also do well to coordinate with sanc- Michigan, has worked on west coast marine tuary management on their Water conservation issues for the past 14 years and forging a stewardship approach to re- represents "conservation interests" on the duce pollution associated with the Quality Protection Program and on Monterey Bay National Marine Sanctuary agricultural sector. enforcement and monitoring issues of Advisory Council.

46 Endangered Species UPDATE Yo/. 13 No. 12 1996 The Role of Friends of the Sea Otter in Resource Protection - Ellen Faurot-Daniels and - Donald C. Baur Non-governmental organizations advocacy group in the world exclu- stitution and agency scientists andman- (NGOs) can make significant contribu- sively dedicated to sea otters. agers, and asked to participate in tions to research and management FSO currently has a staff of 5 full- construction of management policy. discussions, planning, plan implemen- time professionals, a 10 member Board Without exception, these instances of tation, negotiations, political lobbying, of Trustees, a 15 member Scientific cooperativework have always benefited funding procurement, education, and Advisory Council, and a membership all parties. Because of this, there seems legal and citizen actions. Because they of 4,000 that represents all 50 states and to be a slow awakening by other man- are not bound by the legal and regula- 20 foreign countries. In addition to agement agencies and institutions to the tory encumbrances that government work in the conservation policy realm, positive role NGOs can play if they are agencies often work under, NGOs are FSO has established an educational out- approached early in the decision-mak- uniquely positioned to catalyze action, reach program, responds to requests for ing process. Many conservation NGOs suggest and promote solutions to prob- information on seaotters, sponsors work have access to excellent scientists, policy lems, and use the political process to with university interns studying sea ot- makers and lawyers, all of them con- achieve goals that often cannot be ters, operates aretaueducation Sea Otter scious of the need to utilize the best achieved by those working within gov- Center, and operates a program for the possible evaluative tools available in ernment agencies. identification and training of oil spill reviewing a contentious issue. This paper will focus on how response volunteers (the COAST pro- Friends of the Sea Otter (FSO), as one gram). FSO's contributions to sea otter example of an NGO, has operated in its Many of the issues that led to the conservation effective and singular role as a conser- formation of FSO have persisted in type Friends of the Sea Otter examines vation advocate. The paper looks briefly and intensity, although varying in spe- issues of fisheries utilization and con- at the history of the organization, how it cifics. While the sea otter population is servation, plans for oil spill prevention operates, and FSO's accomplishments recovering in numbers, their range along and response, follows research on envi- and current focus. the central California coast is still lim- ronmental contaminants,and endeavors ited, and the threats from oil spills, to increase scientific and public under- How and why Friends of the Sea human interactions, and environmental standings of fluctuations in sea otter Otter was started contamination are still very much numbers, distribution, and habitat utili- Friends of the Sea Otter began in present. zation. FSO is involved in a variety of 1968. It was born of the commitment of sea otter science and policy issues two people, Margaret Owings and Jim General operating principles throughout the North Pacific, in nego- Mattison, Jr., to protect the southern sea As a result of all the communica- tiations of national and international otter against the threat of further endan- tions and actions required to put together environmental legislation, and in con- germent or extinction. In the late 1960s cogent policy positions, FSOcommonly sultations for recovery planning for the the southern sea otter population was is in the middle of a communications southern sea otter. Some policy actions small, located only along a 150 mile "node." This access to information and have been almost exclusively the prov- band of central Californiacoastline,and issues allows us to function effectively ince of FSO action, for example the subject to strong competition from the as a citizen-based action group. listing of southern sea otters under the commercial abalone fishery. There was Because FSO's focus is on the ma- federal Endangered Species Act (ESA), a lack of knowledge about the behavior rine environment, for which the state and lobbying for restrictions on Califor- and biology of sea otters, and the range and federal governments are the sole nia coastal gillnets. Without the efforts and seriousness of perceived threats to "landlords," it tends to look toward af- of a focused advocacy group such as their populations. The focus of FSO's fecting government policy. FSO also Friends of the Sea Otter, many of those founders was to alert the public and puts a premium on collaboration with accomplishments could not have been elected officials to the pressures sea other non-profit organizations, govern- achieved. More important, perhaps, otter recovery was facing. The founders ment agencies, and scientific NGOs can choose to identify and imple- thought that the organization would be institutions. FSO can and does enlist ment appropriate solutions,not stopping able to complete the task of sea otter the help of environmental lawyers in with a simple acknowledgment and no- protection within two years. What determining the best possible policy tification of a problem. started as a two-person, grassroots ef- course to take; while lawsuits are used Over the years, the specific tasks fort has grown over the years into a as a last resort, FSO will pursue that and accomplishmentsof FSO have fallen well-established, highly respected con- avenue if necessary. into several different categories. The servation organization and the only FSO is sometimes consulted by in- first is scientific research and

Vol. 13 No. 12 1996 Endangered Species UPDATE 47 monitoring. Examples include: establishing a scientific advisory council (including representatives from U.C. Santa Cruz and Stanford University); initiating studies on sea otter bi- ology and behavior by providing financial support to field scientists; tracking fisheries monitoring and enforcement efforts of California Department of Fish and Game (CDFG) and U.S. Fish and Wildlife Service; participating in sea otter censuses on the mainland and San Nicolas Island; and establishing COAST (a volunteer oil spill response program). A second area of FSO tasks and Photograph by Jeff Foott accomplishments is in the area of ad- vocacy and lobbying, for example: scientists, agency managers, politicians experts spanning months or even years; testifying on California commer- to discuss issues related to sea otter efforts to implement our recommenda- cial fisheries legislation; population or habitat protection. tions take even longer. providing Congressional testi- Extensive effort is often expended mony on marine mammal protective on a particular issue. For instance, the FSO's current focus legislation; 1977 listing of southern sea otters as The recently released draft revised participating in reauthorizations threatened under the ESA and the 1986 southern sea otter recovery plan (U.S. of the Marine Mammal Protection restriction on use of coastal gill nets Fish and Wildlife Service 1996; see Act, Endangered Species Act, Clean both involved extensive petitioning and Benz, Recovery Plan, this issue) pro- Water Act, and Magnuson Fisheries meetings with agencies and politicians, vides a timely example of how FSO Act; in addition to preparation of political identifies and resolves issues. FSO has providing legal challenges to Na- briefing and public education materi- a number of concerns with the second tive Alaskan hunting rights; als. The translocation of sea otters to recovery plan, which fall into the fol- acquiring restrictions on use of San Nicolas Island (see Benz, Attempts lowing two categories. coastal gill and trammel nets; and to Reintroduce, this issue) involved 3 supporting establishment of the years of meetings, report reviews, and Technical concerns Monterey Bay National Marine Sanc- numerous phone and meeting conver- These are primarily based on the tuary. sations in addition to actual participa- narrow focus of the recovery plan. The Establishing funding for sea otter tion in the translocation effort and fol- emphasis on calculating the number of protection is another areaof tasks, which low-up activities, which continue to- sea otters needed to provide a margin of include: day. Work on designation of the safety following a major oil spill procuring ongoing funding for Monterey Bay National Marine Sanctu- downplays or ignores several other im- CDFG marine enforcementprograms; ary (see Saunders, this issue) involved a portant considerations that need to be securing salary and operating funds steady 10 year effort, and continues comprehensively addressed. These in- for Russian sea otter biologists; and today with ongoing participation in con- clude the limited range and remaining securing reallocation of federal servation working groups, and review threats within the range. Also, better oil funds to National Biological Service of Sanctuary regulations and proposed spill prevention policies are needed to biologists. exemptions. The 1994negotiations over protect essential habitat. FSO believes Finally, FSO is involved with pub- the reauthorization of the Marine Mam- that finding at least one tangible and lic education efforts, including: mal Protection Act involved several significant oil spill prevention technique working with film producers, pho- multi-day meetings, drafts and redrafts to formalize and implement will be the tographers and authors to relay the of language, conference calls to nego- only way to effectively protect the coast sea otter story; tiation participants, and action alerts to and its resources. writing and circulating sea otter members. Similarly, work involving A second area of concern is with issue papers; and the second southern sea otter recovery the sea otter population health. Data meeting with resource interest plan requires extensive efforts on the from the past 5 years indicate that nearly groups, industry, environmentalists, part of our science, policy, and legal 40% of the dead sea otters examined

48 Endangered Species UPDATE Vol. 13 No. 12 1996 had an infection at the time of death (see boats; and (4) restricted genetic diver- other responsible research and policy Thomas and Cole, this issue). While the sity due to the severely reduced state of partners must be forged and supported types of diseases have been catalogued, the population. As a matter of law, even by the FWS. Toward that end, FSO will we know little about how sea otters if the second recovery plan established over the next year be working with encounter these diseases, if they are delisting criteria to address all of the institutions and agencies to (I) identify encountering them at greater rates than original threats, the species could not be ESA pre-delisting goals; (2) identify in the past, or whether their resistance to determined recovered unless any new policy development linkages; (3) con- natural or new types of infections has threats also had been fully analyzed, duct strategic planning for future changed. Research is necessary to de- addressed, and resolved. research, keyed to the pre-delisting termine sea otter infection rates, how goals; (4) lobby to have consensus-based and to what degree infections are com- Conclusion and strategic planning and timetables be- municable, and the incidence and impact recommendations come part of the second southern sea of environmental contaminants, toxins, The next five years will be pivotal otter recovery plan; and (5) procure and parasites on sea otters and their for sea otter research and recovery. The additional funding and policy support critical habitat. southern sea otter population has appar- to achieve these goals. The second recovery plan recog- ently done just well enough in terms of Implementing these revisions nizes the need to research the impact of population growth to move it down the would not only set the southern sea otter sea otters on shellfish resources, but priority list in terms of U.S. Fish and on a track for recovery on a reasonable there is no identification of a similar Wildlife Service (FWS) management schedule, but could serve as an example need to study the abundance, distribu- efforts and dollars. Ironically, federal for other recovery plans on how to tion, and quality of food resources management tends to be reduced just as achieve agreement among interested available to the sea otters. If sea otters species are on the brink of full recovery. parties. We encourage FWS to take within their current range become food- With the ESA under attack, federal advantage of this opportunity to dem- limited as aresult of human overharvest mandates for species' recovery at an all onstrate just how effectively arecovery of shellfish, or as a result of contamina- time high, and budgets for recovery planning process under the ESA can tion of the food supply, then recovery efforts being cut, we are concerned that work when a consultative process is levels sufficient for ESA delisting, and FWS involvement with sea otters has used and proper consideration is given ongoing population stability, cannot be been lessened. However, FSO believes to the needs of the affected species. The assured. that we can utilize persistence, creativ- second southern sea otter recovery plan ity and cooperative efforts among state can illustrate the necessity of a well- Legal concerns and federal agencies, academic institu- managed, adequately funded recovery The chief legal concern with the tions, research facilities, industry, and planning process that calls upon the second recovery plan is the failure of conservation groups to successfully expertise of all affected parties. the oil spill risk analysis to adopt the complete the task of southern sea otter It is in just these types of endeavors conservative approach required by the recovery under the ESA. that NGOs such as FSO can be ex- ESA. The efficacy of the second recov- We recommend two broad actions. tremely effective. Partnered with the ery plan relies upon the prediction that First, the ESA needs to survive its next efforts of agencies andinstitutions,FSO a 250,000 barrel oil spill would contact reauthorization with its basic protective can serve to ally disparate entities and sea otters at least 10% of the time and tenets intact. This will involve exten- catalyze positive change. result in no more than 800 otter deaths. sive negotiations over at least the next This estimate does not comport with the year. FSO expects to be intensively Literature Cited legal intent that the ESA be adminis- involved in this effort. U.S. Fish and Wildlife Sewice. 1996. Southern tered in a conservative manner (i.e., to Second, the most recent draft of the sea otter recovery plan, 1996 draft. Ventura, California. 41 pp. give the benefit of the doubt to the second southern sea otter recovery plan species). needs to be updated significantly as it A second area of concern is that the moves toward its final form, and must second recovery plan does not ad- be made to reflect new concerns over equately address the full range of threats sea otter population health, and the need that caused the species to be listed as to provide more definitive habitat pro- threatened in 1977. The risk posed by tection from oil spills. Equally Ellen Faurot-Daniels is Science Director with Friends of the Sea Otter. She previously served oil spills clearly was the greatest threat important, mechanisms for implement- with the California Department of Fish and Game at the time. But all of the following ing the final recommendations of the and the U.S. Fish and Wildlife Service on threats also were identified: (1) increas- second recovery plan must be identi- numerous sea otter research and habitat evaluation ing chemical, bacteriological and metal fied. Given the greatly decreased programs. Don Baur is a partner with the law fm of Perkins Coie. He has sewed as General pollution; (2) inadequate habitat pro- resources and efforts of the FWS di- Counsel of the Marine Mammal Commission and tection under existing law; (3) direct rected toward southern sea otter as an attorney in the Solicitor's Office of the killings by shooting and collision with recovery, cooperative linkages with Department of the Interior.

Vol. 13 No, 12 1996 Endangered Species UPDATE 49 The Role of Rehabilitation in Sea Otter Conservation Efforts _ Thomas D. Williams and - Terrie M. Williams Rehabilitation programs for sea Public perceptionof rehabilltation bilitation. Strong humadanimal bonds otters, as well as other wildlife, are and conservation result in people being negatively im- supported by arguments based on psy- The U.S. Environmental Protec- pacted when confronted by animals in chological impacts on the public, tion Agency (EPA) has recognized the distress. Preventing rescue attempts practicality, knowledge enhancement, dichotomy between public perception would increase the feelings of helpless- and the value of the individual animal as and scientists' understanding of envi- ness among those sensitive to animal well as the species. Conversely, poten- ronmental problems. Action and issues. In contrast, people experience a tial deleterious effects upon the gene priorities are often tempered by the in- psychological boost through the sense pool, stress to individual animals, the fluence of public concerns on national that they are returning something to the potential spread of disease, and inap- legislation and funding. As aresult, the world by caring for distressed animals. propriate use of limited resources argue EPA budget and staff are often directed Rehabilitation programs broaden against rehabilitation efforts. A good at environmental problems perceived community ownership of problems in example of this conflict was the rescue as serious by the general public but not the environment and empower people of sea otters following the Exxon Valdez necessarily justifiable at the population to act and learn about those problems. oil spill. Rehabilitation efforts were conservation level (EnvironmentalPro- Educational programs are crucial for disappointing, with nearly one quarter tection Agency 1990). For example, oil linking the immediate satisfaction of of the rehabilitated and released sea spills were considered a relatively low caring for an individual animal with otters presumed to have died soon after risk problem due to the resiliency of larger conservation issues. Programs at release, based on post-release monitor- ecosystems to such short-term insults. the public aquaria and rehabilitation ing of radio instrumented animals Despite this, considerable resources facilities provide opportunities to view (Monnett et al. 1990). Furthermore, the have been directed towards the mitiga- animals not easily seen in the wild, potential contribution of the rehabilita- tion of the impact of oil spills on wildlife. resulting in a sense of caring and respect tion effort has been questioned in view In the aftermath of the Exxon Valdez oil for the animals. Public education on the of the fact that although a large number spill, for example, 225 sea otters were value of these animals towards conser- of sea otters were impacted (estimated rehabilitated at a cost of $18.3 million, vation of the population is necessary in at 1000 to more than 5000 individuals) or over $8 1,300 per otter. developing cooperative conservation this number does not represent a signifi- Historically, wildlife rehabilitation programs involving the public, research- cant portion of the total Alaskan efforts in the United States have re- ers, rehabilitation facilities, aquaria, population of 150,000 - 200,000 otters flected the public's desire to serve as government officials, and animal inter- (Garrott et al., 1993). This paper will stewards of the environment. The rev- est groups. look at the lessons of the Exxon Valdez erence for life that evolved from our The institution of a cooperative spill and will examine the questions: historic traditions is denigrated if the conservationprogram will require afun- how will these issues influence the role needs of fellow human beings or ani- damental change in thinking by the of rehabilitation programs in future sea mals are ignored. The moral issue general public, which should be based otter conservation? becomes an even more compelling force on a foundation of scientific fact. Rather for rehabilita- than focus on the individual animal as

Dead Oiled sea Otter PUP, resuking from the Exxon Valwoll spill, c o m p e 11 i n g than the needs of the population or the Photograph courtesy of Friends of the Sea Otter. forces for reha- species. This is complicated by media-

50 Endangered Species UPDATE Vol. 13 No. 12 1996 The individual This may serve as the only research sea otter in a rehabili- option for species that do poorly in tation program, how- captivity or whose populations have ever, provides much declined to the point that disturbance more than a human by scientists would be detrimental. interest personality. For example, the sea otter may pro- These animals repre- vide clues about a variety of other sent an invaluable link endangered mustelids including semi- between the scientific aquatic (i.e. Amazonian otters community and wild (Pteronura brasiliensis)) and terres- populations. Combin- trial (i.e. black-footed ferret (Mustela ing the expertise and nigripes)) species. resources of zoologi- cal parks, rehabilita- Individual otters aspart of securepopu- tion personnel, and lations environmental scien- Natural or anthropogenic factors tists is an important di- may create habitats that are temporarily mension to the timely untenable for a species (Foose 1989). conservation of the Captivity offers safe haven for preserv- species. ing biodiversity until the environmental threat is removed. The sea otter and the Individual otters as California condor (Gymnogyps representatives of the califomianus) are good examples of species such environmentally threatened spe- Sea otter being washed as part of the rehabilitation The sheer num- cies. Inadequate food resources, habitat effort after the Exxon Valdez oil spill. Photograph ber of species facing loss and toxins have created an unsuit- courtesy of Friends of the Sea Otter. extinction far out- able environment for supporting the created "personalities:"such asLazarus, weighs our capabilities to either house California condor (Verner 1978). To the sea otter who made a convenient on- or study them (Soul6 et al. 1986). In alleviate environmental pressures, the camera recovery during the Exxon addition, there is a paucity of informa- few remaining wild California condors Valdez spill, and April, therehabilitated tion on the basic physiology, behavior, were captured and placed in a captive sea otter released by the Monterey Bay immunology, genetic diversity, inter- breeding program. Likewise, pre- Aquarium who was the subject of peri- actions andenvironmentalrequirements emptive capture and long-term holding odic cover stories in local papers for of sea otters and their prey. Unfortu- may be the only alternative for the Cali- months. Public empathy for sea otters nately, this basic information is critical fornia sea otter in the event of a and the promotion of rehabilitated ani- for identifying the environmental de- catastrophic oil spill (Degange et al. mals as personalities creates a fertile mands of a population and for 1995; see Brennan and Houck, this is- environment for financial, popular, or developing intelligent management sue). Such critical measures may be political gain. plans (Ralls andBrownel1 1989). Reha- needed until habitats can be matched to Debates concerning rehabilitation bilitation programs offer innumerable the environmental requirements of the programs often reveal a basic misun- research opportunities, and the knowl- animals. derstanding by the general public of edge gained may have significant species conservation and the role of long-term importance for the survival Individual otters as members offuture scientific research and rehabilitation in of the population as a whole. Work on wild populations the preservation of biodiversity. They individual sea otters allows researchers New methods and technologies for also illustrate the problem of trying to to develop effective capture, transpor- captive breeding and reintroductions to reach consensus amid the conflicting tation, treatment and husbandry the wild offer a lifeline for endangered goals associated with individual animal techniques. Rehabilitating animals of- populations. When coordinated with rights and the conservation of an entire ten provides biomedical and habitat preservation, programs involv- species or population. In reviewing the physiological standards regarding ex- ing rehabilitated animals serve as a costly sea otter rehabilitation programs posure to pathogens, parasites and powerful tool for restoring communi- following the Exxon Valdez oil spill, toxins. ties and ecosystems (Stanley Price Estes (1991) questioned the value of Carefully planned and executed 1989). The black-footed ferret (Mustela efforts focussed on individual animals rehabilitationprograms can advance our nigripes) in Wyoming (Seal 1989), the when resources are limited and a popu- understanding of the basic biology of a Arabian oryx (Olyx leucoryn) in Oman lation or species is not threatened with species, and thus improve the scientific (Stanley Price 1989) and the California extinction. foundation for conservation programs. condor in southern California (Verner

Vol. 13 No. 12 1996 Endangered Species UPDATE 51 M.A. Bogan, and S.H. Anderson, editors. Conservation biology and the black-footed ferret. Yale University Press, New Haven, Connecticut. 302 pp. Garrott, R.A., L.L. Eberhardt, and D. M. Burn. Biodiversity 1993. Mortality of sea otters in Prince Will- Conservation\ iams Sound following the Exron Valdez oil /"- spill. Marine Mammal Science 9(4):343-359. Monnett, C., L.M. Rotterman, C. Stack, and C. Monson. 1990. Post-release monitoring of ra- dio-instmmented sea otters in Prince William Sound. Pages 400-420 in K. Bayha and J. Kormendy, editors. Sea otter symposium: ducation Programs proceedings of a symposium to evaluate the response effort on behalf of sea otters after the TNExron Valdezoil spill into Prince William \ Sound, Anchorage, Alaska. U.S. Fish and IrRehabilitation kwarch ~rogramsl / I \ Wildlife Service Biological Report 90(12). 126 pp. LABORATORY Ralls, K. and R.L. Brownell, Jr. 1989. Protected FIELD species-research permits and the value of ba- Basic Research on Assessment of sic research. BioScience 39(6): 394-396. Individual Animals Wild Populations Seal, U.S. 1989. Conservation biology and the - black-footed ferret. In U.S. Seal, E.T. Thorne, M.A. Bogan, and S.H. Anderson, editors. Yale University Press, New Haven, Connecticut. Figure 1. A theoretical Biodiversity Pyramid. Key elementsr in achieving conservation 302 pp. goals from rehabilitation programs are a foundation of research on individuals and Stanley Price, M.R. 1989. Animal reintroduc- populations followed by education of the public and government agencies. tions: the Arabian oryx in Oman. Cambridge University Press, Cambridge, United King- 1978) are recent examples of scientific education programs, research findings dom. 291 pp. programs designed to "seed" the envi- can be used to shape public perception Soul6, M.E., M. Gilpin, W.G. Conway, and J.T. Foose. 1986. The millennium ark: how long ronment with wildlife from captive about conservation issues. Public em- a voyage, how many staterooms, how many populations. Similar considerations pathy for the environment and animals passengers? Zoo Biology 5101-113. should be given to the southern sea otter can then translate into action by state, U.S. Environmental Protection Agency. 1990. population. Hallmarks common to these federal and international agencies. The Reducing risk: setting priorities and strategies for environmental protection. Report of the programs were captive breeding and a cooperative goal should be to develop Science Advisory Board: Relative Risk comprehensive knowledge of the biol- sound conservation measures for ma- Reduction Strategies Committee. SAB-EC- ogy of the species. By guaranteeing the rine biodiversity based on scientific fact. 90-021.26 pp. Admittedly, the challenge will be Verner, J. 1978. Californiacondors: status of the success of the individual, the programs recovery effort. General Technical Report were able to enhance population levels in the development of multi-disciplin- PSW-28. Southwest Forest and Range Experi- in the wild. ary strategic plans for rehabilitation that mental Station., Forest Service, U.S. incorporateresearch, education and con- Department of Agriculture, Berkeley, Cali- Turning rehabilitation into servation. The optimum conservation fornia. 30 pp. conservation-the Biodiversity strategy for any species will incorporate Pyramid captive and wild populations as interac- Conservation of biodiversity can tive components (Foose 1989). Other- be thought of as a pyramid, with knowl- wise, rehabilitation programs will be edge as the base (see Figure 1). This limited to serving the emotional needs foundation requires information about of the public rather than the species the needs of individual animals and the affected. requirements of wild populations. It relies on basic research conducted on Literature Cited animals under human care as well as an Degange, R., B.E. Ballachey, and K. Bayha. assessment ofthe numbers andenviron- 1995. Release strategies for rehabilitated sea otters. Pages 141-154 in T.M. Williams and faced by animals in R.W. Davis. editors. Emergency". care and re- their native habitats. Research supported habilitation of sea otters. University of Alaska by rehabilitation programs- - and aquari- Press, Fairbanks, Alaska. can provide the vital link Estes, J.A. 1991. Catastrophes and conserva- tion: lessons from sea otters and the Exxon these research objectives. With plan- "oldel- oil soill. Science 254: 1596. Thomas D. Williams is at the Monterey Bay ning,- the result will be a direct applica-- - Foose, T.J. 196. Species survival plans: the role Aquarium, Monterey, CA 93940. Teme M. of captive propagation in conservation strate- tion of research data to the conservation Williams is at the Department of Biology, UC gies. Pages 210-222 in U.S. Seal, E.T. Thorne, of wild popu~at~ons~when linked to Santa Cruz, Santa Cruz, CA 95064.

52 Endangered Species UPDATE Vol. 13 No. 12 1996 Oiled Wildlife Care for Sea Otters and Other Marine Animals in California: A Government, University, Private Sector, Non-Prof it Cooperative David A. Jessup, Jonna A. K. Mazet, and Jack Ames

The draft revised southern sea otter agement is somewhat controversial. wildlife agencies actually provide care recovery plan released by the U.S. Fish However, while treatment and recovery for wildlife compromised by oil spills and Wildlife Service (FWS) for public programs for the non-threatened, ex- or other human activities. The estab- review andcomment of June 1996states panding sea otter population in Alaska lishment of a large and complex net- that "...the likelihood of sea otters per- may be controversial, the California situ- work for the care of oiled wildlife be- sisting in California is currently deter- ation is very different indeed. Califor- fore a major oil spill is unprecedented. mined by whether a major oil spill oc- nia sea otters are state and federally But, the spectacle of dead and dying curs within the seaottersrange...." (U.S. listed, the population is only slowly Alaskan sea otters repeatedly shown on Fish and Wildlife Service 1996. p. vii). recovering, and a single large oil tanker national television throughout the spring It further states that "...two approaches spill could contaminate a major portion of 1989 subsequent to the Exxon Valdez have been identified that would lead to of the entire sea otter range. spill, followed shortly by the American delisting the southern sea otter under This paper will discuss the Oiled Trader spill off Huntington Beach near the Endangered Species Act (ESA): (1) Wildlife Veterinary Care and Research Los Angeles, California, galvanized increasing the range of otters in Califor- Center (OWVCRC) in Santa Cruz, Cali- public and political support in Califor- nia to reduce the risk of a single oil spill fornia, that will serve as a focus for oil nia for action. In 1990 the legislature of event reducing the otter population below spill response and sea otter biomedical California enacted the Lempert-Keene- a level that is viable, and (2) decreasing research, and a larger Oiled Wildlife Seastrand Oil Spill Prevention and Re- the risk to otters that a major oil spill event Care Network (OWCN) that serves all sponse Act (SB 2040), which estab- within their range will occur" (U.S. Fish species along the California coast, in- lished the OSPR within the CDFG, and and Wildlife Service 1996. p. vii). cluding its development, current status, placed a $.04 per barrel fee on oil trans- Efforts to increase the range of the and potential contributions to species con- ported or processed in California, the southern sea otter (the first approach) servation. proceeds of which are to be used, among have met with limited success. Reasons Although the plight of the southern many other things, for care of wildlife for this, for the slow rate of expansion of sea otter was not the driving force be- affected by oil spills. SB 2040 requires the sea otter population, and for the hind the development of an Oiled Wild- that oiled wildlife receive "best achiev- apparently high rate of mortalities in life Care Network (described below) in able treatment" and "the establishment adults, are poorly understood. Efforts California (see Figure I), it was cer- of rescue and rehabilitation stations for to decrease the risk of a major oil spill tainly a major consideration. Every sea birds, sea otters, and other marine (the second approach) include moving effort has been made in the develop- mammals." The first of these stations all Trans-AlaskaPipeline System tanker ment of the OWCN, and OSPR's other was to be built within the range of the traffic (but not all non-oil carrying ves- programs, to identify methods by which southern sea otter. sels and barges) beyond 50 miles off the impacts of oil spills in the sea otter OSPR is currently building this sta- coast. These efforts are under the lead- range can be reduced. In addition, the tion (OWVCRC) at the University of ership of the California Department of OWCN will ensure that any sea otters California, Santa Cruz (UCSC). When Fish and Game-Office of Oil Spill Pre- that do become oiled will receive the completed in the summer of 1997 at a vention and Response (CDFG-OSPR) best achievable treatment and that their cost of approximately $5 million dol- and the U.S. Coast Guard. potential for survival and release will be lars, it will be capable of caring for 125 A third approach toward improv- maximized. Thus, the OWCN and as- sea otters, but flexible enough to care ing the likelihood that sea otters would sociated monitoring, research and man- for other species of marine animals and survive a major oil spill, the develop- agement efforts by the CDFG and coop- house ongoing joint and cooperative ment of state-of-the-art centers for sea erating agencies and organizations may research projects. By locating this fa- otter care and research, is not men- hasten the recovery of the southern sea cility adjacent to California's premier tioned in the draft revised southern sea otter and may help document their health marine ecotoxicology laboratory (the otter recovery plan. That may be be- and status in support of federal delisting. Joseph L. Long Marine Laboratory on cause, given the relatively high costs the UCSC campus), and by commit- and mortality rates for oiled sea otters in The Oiled Wildlife Care Network ting to support appropriate research, Alaska following the Exxon Valdez in- Although state wildlife agencies OSPR has assured that its OWVCRC cident, this approach to sea otter man- are trustees for wildlife resources, few will play a prominent role is sea otter

Vol. 13 No. 12 1996 Endangered Species UPDATE 53 and marine mammal research and man- be completed by the end of 1997. Each built to provide additional facilities for agement when not being used for oil of these centers is being developed in the care of oiled sea otters should the spill response. conjunction with an existing marine capacity of the Santa Cruz OWVCRC In 1993, a second piece of park, wildlife rehabilitation program, be exceeded or should it be medically legislation,SB 775, which was amended educational institution, or combination expedient to treat oiled sea otters at by AB 1549 in 1995, allowed OSPR of compatible programs. The programs separate locations. approximately $9 million dollars over a at each center have separate and To assure that oiled wildlife would 4 year period to help build the other additional sources of financial,political, immediately begin receiving "best mandated "rescue and rehabilitation and personnel support. This approach achievable treatment," OSPR developed stations" in the OWCN, and allow the again assures that all OWCN centers working relationships assured by a OWCN to serve all marine species along will provide useful and appreciated Memoranda of Understanding with 15 the entire California coast. These services to the people of California when existing private non-profit wildlife re- additional centers are being developed not in use for oil spill response (see habilitation organizations in 1995 and in San Diego, Orange County, Los current programs section below). Two incorporated them into the OWCN. Angeles, Santa Barbara, the San centers, one at Sea World in San Diego These organizations have agreed to as- Francisco Bay Area and Humboldt and one at The Marine Mammal Center sist OSPR with personnel and small County. Most of these centers should in Sausalito, are being designed and facilities to respond to the needs of oiled wildlife. Essentially all of

the organizationsu that cur- rently provide care for ma- rine mammals as part of the & California Marine Mammal Stranding Network under the I jurisdiction of the National Marine Fisheries Service (NMFS) are part of the OWCN. OSPR and NMFS have negotiated a Memoran- dum of Agreement to con- firm this state and federal agency cooperation during andbetween oil spills. OSPR has, in turn, equipped and supplied these 15 additional existing organizations with whatever they have needed to deliver "best achievable treatment" to oiled wildlife and has conducted, and will continue to conduct, training courses and symposia on state-of-the-art medical care and washing procedures, sample collection, record keeping, etc. In some cases the physical facilities have been improved or expanded at these existing private wild- life rehabilitation centers. These smaller wildlife 4 Marine Mammals rehabilitation organizations can provide a pool of trained Sea Otters volunteers for oiled animal care that may be utilized at Cooperating Organizations more distant locations in the event of a catastrophic spill Figure 1. Location and focus of oiied wildlife care network (OWCN) facilities. requiring large amounts of

54 Endangered Species UPDATE Vd. 13 No. 12 1996 person power. The cooperation and support of appropriate technology de- All of this research is designed to mutual respect that develops when velopment and research allows OSPR improve our ability to provide care for private, community-supported to accomplish these aspects of the pro- oiled marine wildlife, and to improve organizations and government work gram through the Wildlife Health Cen- our ability to determine the immediate together results in community (thus ter at the University of California,Davis. and the sublethal effects of oil pollution political) support for the overall After 1998, U.C. Davis will be the prin- on marine animal populations. It may program. It is also hoped that this type cipal operator of the OWCN. The also enable federal and state trustee of cooperation and assistance will OWCN program clearly provides a ser- agencies to complete comprehensive encourage the continued improvement vice to the State and its wildlife re- wildlife injury assessments as part of and professionalization of wildlife sources and is supported by top univer- the Natural Resource Damage Assess- rehabilitation organizations. sity administration at three campuses. ment or joint injury determination. The program represents a unique col- Settlements with responsible parties will Current program status laboration between scientific, educa- enable trustee agencies to undertake To meet the mandate for immedi- tional, non-profit, and government or- restoration of injured wildlife resources. ate veterinary response capabilities for ganizations, and has attracted some of The OWCN allows the petroleum oiled wildlife, the OWCN has devel- the nation's best veterinary and wildlife industry to meet its legal requirements oped a veterinary team that includes health professionals into the oiled wild- (under SB 2040) to provide for the care individuals from government agencies, life care and response arena. A com- of potentially oiled wildlife in all loca- private practice, universities, research petitive grants program has been estab- tions where they do business in Califor- institutes, wildlife rehabilitation cen- lished that is open to proposals from any nia. The OWCN provides this in a ters, and marine parks. Participants agency, company, university or research cost-effective and highly professional share pertinent information, improve institution. The first request for propos- manner. Because a portion of the and standardizetreatment protocols, and als has been published and $100,000 interest on the State Oil Spill Re- cooperate in research. OSPR has built became available in 1996. The level of sponse Fund mandated by SB 2040 is and outfitted a pair of mobile veterinary funding will increase to $200,000 in being used to build and support the laboratories and animal transport, wash- 1997 and to $325,000 in 1998 and be- OWCN, no company or potential re- ing, and care trailers that can be mobi- yond. Research that may benefit sea sponsible party has to pay additional lized to reach anywhere in California otters is very likely to be supported and fees out-of-pocket unless or until they within 24 hours. A trailer specifically advanced as a result of this initiative. are responsible for an oil spill. How- designed to rapidly transport large num- Currently, other OSPR funded re- ever, responsible parties which cite bers of oiled birds to or between centers search at Californiaunivmities andHubbs the OWCN in their oil spill contin- has been designed and built. Small Sea World ResearchInstituteare address- gency plans (currently this is essen- trailers which contain hazing equipment ing the effects of oil on sea otters, harbor tially all contingency plan holders in and supplies needed during the first few seals, and key marine bird species. Spe- California) will utilize the OWCN un- hours following an oil spill and which cific research programs address: (1) the der OSPR's guidance, and will pay all can transport all-terrain vehicles needed effects of oil on various organ systems in costs of caring for oiled wildlife. Indus- for wildlife surveillance and pickup have sea otters; (2) immediate detection of try has representatives on the OWCN been constructed and deployed. The trace amounts of oil in the fur and feathers Advisory Board and the OWCN Scien- large " 18 wheeler" mobile oily bird care of live animals; (3) characterizing the tific Review Board. As may be imag- and washing trailer (MOBCART), potential effects of oil on the immune ined, this type of cooperative approach which was designed by International response of sea otters; (4) characterizing has received very broad support in the Bird Rescue and Research Center the immune response of harbor seals in- regulated private sector. (IBRRC) and built by Chevron and cluding differentiating the effects of the The OWCN is one of the first gov- Clean Seas, will soon be available for rehabilitation process from exposure to ernment, private industry, non-profit, response in California as well. The oil and other health hazard; (5) estab- professional educationallresearchinsti- development of regional OWCN facili- lishing baseline health information for tution partnerships of its kind. This ties will substantially improve local pinnipeds; (6) updating information on program also represents a State govern- wildlife veterinary care capability as the status of marine mammal popula- ment commitment to integrate wildlife well as reduce the cost of oiled wildlife tions and delineating populations at care with resource management and rehabilitation, which has traditionally greatest risk of exposure to oil; and (7) ongoing research. This paradigm shift, included the development of interim establishing baseline health informa- from concern only about populations facilities (see Williams and Williams, tion on key marine bird species. An to concern for individual animals as this issue). additional effect of this commitment to well as populations, has proven a chal- A third piece of legislation intro- research has been support of at least lenge to resource agency personnel duced in 1995, AB 1549, expanded the four individuals pursuing doctoral de- and their traditional way of thinking OWCN mandate to include operations grees and support for the post-doctoral and operating. The OWCN's devel- and maintenance of the OWCN, and research of three other individuals. opment has been difficult and compli-

Vo1. 13 No. 12 1996 Endangered Species UPDATE 55 cated, but it has the potential to pro- appears that substantial efforts will need understand factor or factors limiting vide optimal care for oiled wildlife, to be made to continue tracking morbid- current growth rate of the California and to also make tremendous contribu- ity and mortality, to better understand population ...." (U. S. Fish and Wildlife tions to sea otter and marine animal the effects of environmental contami- Service 1996. p. x) or for section 6 conservation. nants, diseases and parasites, as well as (ESA) funds. the immune response of southern sea The OWCN is a real change from Conclusions and otters and factors that may compromise past government-led programs that only recommendations it. With joint funding this type of pro- gave obligations to the private sector In California the prevention of and gram would be welcome at the Santa and non-governmental organizations response to oil spills will remain the Cruz OWVCRC andlor other OWCN and provided few opportunities. Funds, focus of OSPR. To the extent these centers. The Santa Cruz OWVCRC supplies and training are flowing from a programs are effective, they will im- could become a world center for sea government program to the private sec- prove the likelihood of recovery for the otter research and management, but tor, and the private sector and universi- southern sea otter. Inspection of petro- FWS and the former National Biologi- ties have input into the program's opera- leum facilities, pipelines, and transpor- cal Service (NBS) will need to facilitate tions. The OWCN is an example of a tation vessels, and enforcement of ma- and contribute. truly cooperative approach to research, rine safety regulations, may become Beyond reducing the potential im- governance, and public service. Re- more intense. Further restrictions on pacts of an oil spill on sea otters and cently cooperative efforts to develop a petroleum shipping could be consid- other marine animals, the OWCN and comprehensive southern sea otter re- ered. Such technological innovations OSPR's Veterinary Services Unit could search program, which includes CDFG, as Vessel Traffic Identification System do much more. Because it brings sub- FWS, NBS, UCSC, The Marine Mam- may help reduce the risk of shipping stantial fiscal and physical resources to mal Center, and the Monterey Bay accidents. bare, the OWCN could facilitate the Aquarium have begun. Large multi- If the OWCN, with all its various real implementation of the Federal Ma- organizational cooperative programs programs and partners, is to succeed in rine Mammal Stranding and Response have been relatively uncommon in the lowering the risk that a major oil spill Act in California. The OWVCRC at past. They represent a recognition that will reduce the southern sea otter popu- Santa Cruz could assist in understand- no single agency, organization or uni- lation (and other sensitive marine birds, ing the effects of human activities on versity has all of the resources or politi- mammals and turtles) below viable sea birds and marine life within the cal will, all of the best personnel or population levels, as well as generally National Marine Sanctuaries of North- ideas to provide optimal conservation improving our understanding of the ern California. If that is to happen, of sensitive or listed species. There is health of sea otters and other marine however, National Marine Fisheries also a recognition that government and species, this cooperative program must Service (NMFS) and National Oce- non-governmental organizations need be sustained and supported by CDFG- anic and Atmospheric Administration to try to be less insular, more flexible OSPR. With current legislation which must seek, facilitate, and support those and more cooperative; that universities allows OSPR the use up to $1.3 million programs. can provide service along with their per year of the interest off the Emer- To date the majority of the funding, research programs; and that in the fu- gency Response Fund to operate and equipment, and some key personnel for ture we will increasingly need to pool maintain the OWCN through the U.C. the OWCN have come from CDFG- our financial and personnel resources. Davis Wildlife Health Center when the OSPR. Non-governmental organiza- It may be difficult for some to embrace building phase is completed in 1998, tions and other agencies such as the these changes and new realities. We support for that program seems assured. FWS, NMFS, and NBS may all have a should remember, however, that the Chi- As noted, there is excellent potential for vested interest in collaboration with and nese symbol for "change" also means cooperatingwith wildlifecare programs, development of compatible programs. "opportunity.I' educational programs, and marine re- Their support may be in the form of search in general, as long as these types joint research projects, facilitating per- Literature Cited of activities, and any additional com- mits, or continuing support for sea otter U.S. Fish and Wildlife Service. 1996. Southern and other marine animal demographic, sea otter recovery plan, 1996 draft. Ventura, patible activities at the various OWCN California. 41 pp. centers unrelated to oil spills, find addi- mortality and health studies. Projects tional and separate sources of funding. related to sea otter recovery and health may be ideal candidates for funds iden- David Jessup works in the Office of Oil Spill OSPR and the OWCN are already Prevention and Response (OSPR) with the contributing to the potential recovery of tified in the draft revised southern sea CalifomiaDepartmentofFish and Game. He can the southern sea otter under the Endan- otter recovery plan to "protect popula- be reached at 1701 Nimbus Road, Suite D, Rancho gered Species Act (ESA), through ac- tion and reduce or eliminate identified Cordova, CA 95670. Jonna Mazet and Jack tivities directly related to oil spill pre- potential limiting factors related to hu- Ames also work for OSPR-CDFG at the University of California-Davis,Wildlife Health vention and response. If the southern man activities including managing pe- Center, Davis, CA95616, and 20LowerRagsdale sea otter is to be delisted, however, it troleum.. .. (and to) conduct research to Drive #100, Monterey, CA 93940, respectively.

56 Endangered Species UPDATE Vol. 13 No. 12 1996 Safeguarding Diversity: Challenges in Developing a Genome Resource Bank for the California Sea Otter Julie A. Long, Shawn E. Larson, and Samuel K. Wasser The U.S. Fish and Wildlife Service ity. For example, in the Monterey area, species. Because cells can endure stor- (FWS) estimates that there are currently a 40% pre-weaning pup mortality rate age at low temperatures (-196OC), 2,400 California sea otters (Enhydra was estimated for 1985-1991(Riedman cryopreservation of gametes and/or lutris nereis) with a range of only 240 et al. 1994). embryos extends the generation inter- miles along the central California coast. The viability of wildlife depends, val of an individual indefinitely. GRBs The relatively low number and small in part, on the level of genetic variation essentially are frozen repositories that range of the California sea otter is cause within species, populations, and indi- provide insurance against loss of ge- for great concern about the fate of this viduals (Wildt et al. 1993). Because the netic diversity by retaining viable germ unique marine species because of the possibility of an oil spill within the plasm from founder animals for future potential for oil spills within the re- California sea otter's habitat is a con- generations (Wildt 1992). In the case of gion (see Bonnell et al., this issue). In stant threat to the continued viability of the California sea otter, a GRB would fact, a major oil spill (>1,000 barrels) this population, conservation efforts safeguard existing genetic diversity within the range of the California sea should include the development of a against not only environmental disas- otter is considered to be the most seri- Genome Resource Bank. ters, but also other unpredictable ous threat to the survival of this species incidents like disease epidemics (see (U.S. Fish andwildlife Service 1996). Genome Resource Banks Thomas and Cole, this issue). A Genome Resource Bank (GRB) For several reasons, a GRB can be The threat of lost genetic diversity is the systematic collection, a powerful conservation tool. Most In the event of a major oil spill, the cryopreservation and use of biological importantly, a GRB offers a high degree California seaotter population may lose materials (gametes, embryos, tissues, of security against loss of genetic diver- not only a large number of animals, but blood products, and DNA) from a given sity by providing an avenue for also a significant proportion of existing genetic diversity. For any species, the potential for inbreeding increases when Disease epidemic Environmental disaster the total number of animals in a popula- tion is reduced. In naturally outbreeding species, such as the sea otter, inbreed- ing depresses reproductive fitness by decreasing genetic variation. In fact, inbreeding depression is a major influ- ence on the cycle of extinction where lowered reproductive fitness results in fewer offspring that, in turn, further increases the chances of inbreeding (see Figure 1). Recent evidence indicates that endangered species actually may give little warning of impending crises due to inbreeding because of a thresh- old relationshipbetween inbreeding and extinction rates (Frankham 1995). Ad- Lowered reproductive efficiency Increased inbreeding ditionally, inbreeding is more likely to and/or immunological competence contribute to population decline for spe- cies with low reproductive rates. The reproductive rate of the sea otter is char- acteristically low, with an estimated annual birth rate of 0.9 pups per female Figure 1. A potential scenario for extinction. Small population size, resulting in California (Riedman et al. 1994). from either one or a combination of factors, increases the opportunity for The reproductive efficiency of the Cali- Incestuous matings. Inbreeding depression isexpressedby reduced reproductive fitness and increased susceptibility to disease. Each subsequent reduction in fornia sea otter is compromised further population size further limits genetic variation, eventually leading to extinction by a relatively high level of pup mortal- (adapted from Wlldt 1994).

Vol. 13 No. 12 1996 Endangered Species UPDATE 57 long-term storage of genetic material. cal application of assisted reproductive bond dissolution, is estimated to be 3- Once established, a GRB can be used as technology and, ultimately, the GRB, 4 days (Riedrnan and Estes 1990). Even a strategic method for managing ex- requires a solid reproductive database. though there appears to be a seasonal change of genetic diversity among wild trend in pupping, births can take place populations. In fact, successful Female reproduction throughout the year (Jameson and cryopreservation of semen from free- Much of the documented informa- Johnson 1993). ranging animals suggests that sperm tion about reproductive biology in the Although a substantial amount of banking also may be a viable approach female California sea otter has been information about female reproductive to promoting genetic diversity in cap- derived from comprehensivefield stud- biology has been accumulated, little is tive populations (Wildt 1989), as well ies (Kenyon 1969; Wendell et al. 1984; known about sea otter endocrinology. as between captive and wild popula- Siniff and Ralls 1991; Jameson and Biologists do not know for certain if tions. Additionally, biomaterials stored Johnson 1993; Riedman et al. 1994), as females are (I) induced ovulators; (2) in a GRB can be used for basic and well as direct examination of reproduc- seasonally polyestrus or monoestrus; or applied research in genetic, disease tive tracts (Sinha et al. 1966; Sinha and (3) how to distinguish between preg- and reproductive studies. For ex- Conaway 1968; Kenyon 1969; nant and nonpregnant states. Such ample, cryopreserved embryos can Schneider 1973; Bodkin et al. 1993). information is critical for the applica- provide precise standards for quanti- Females reach sexual maturity at 4-5 tion of assisted reproductive fying subtle processes like genetic drift years of age and 75% of 14-15 year old technologies. The Seattle Aquarium (Mazur 1984). females have been found to still be and the Center for Wildlife Conserva- The effective use of a GRB re- reproductively active (Bodkin et al. tion, in cooperation with public quires an organized, systematic 1993). Females less than 3 years old aquariums and marine mammal biolo- approach. The Genome Resource Bank- have immature ovaries (Schneider 1973) gists, are conducting along-term project ing Advisory Group, a scientific ranging in size from 7-1 1 mm (Sinha on sea otter endocrinology using a non- advisory group under the auspices of and Conaway 1968.) In mature fe- invasive hormone monitoring technique the American Zoo and Aquarium Asso- males, ovaries are 11-23 mm in length that measures steroid metabolites ex- ciation, serves to guide and facilitate the and enclosed within a bursa. Typically, tracted from fecal samples. Over 350 development of GRBs. Recently, the a single preovulatory 8 mm follicle is samples have been collected from 2 GRB Advisory Group developed a Re- present on the ovary; polyovular fol- female Alaskan sea otters spanning 1 source Guide designed to assist in the licles are rare. Fresh ovulation sites, or year. Preliminary data reveal, for the formulation and implementation of corpora lutea, measure 5-8 mm in diam- first time, annual estrogen and progest- GRBs. Issues to be considered when eter; whereas corpora lutea of the erone profiles in a captive female (see developing a GRB include: (1) current preimplantation period and pregnancy Figure 2). Cyclic estrogen spikes oc- knowledge of life history and reproduc- range in size from 5-1 1 mm and 9-17 curred at 45-60 day intervals, increasing tion; (2) status in the wild; (3) type and mm, respectively (Sinha and Conaway in magnitude until the largest spike, amount of germ plasm to preserve in the 1968). The period of delayed implanta- which was associated with full estrus context of management and genetic tion appears to be variable and may behavior. Ovulation was confmed by goals; (4) technical aspects of germ account for the range of differences in a 10-fold rise in progestins within 10 plasm collection; (5) storage, use and gestation length (Jameson and Johnson days following the estrogen spike and ownership; and (6) available resources 1993). On average, gestation is 6 months continued to rise until 30 days post and funding (AZA Genome Resource and is considered to consist of a 2-3 estrogen spike. Both estrogens and Bank Advisory Group 1996). month pre-implanted and 4 month im- progestins fell off slightly by day 50, planted phase. The peak pupping period and then showed a dramatic and sus- Genome Resource Banking and for the California sea otter in the south- tained rise (3-fold increase for estrogens assisted reproductive technology ern part of the range near Morro Bay and 20-fold increase for progestins) 90 The potential benefits of GRBs for occurs from January to March, with a days post estrogen spike of a presumed maintaining genetic diversity and pre- smaller peak in the late summer to early pregnancy. These data suggest that the serving species depend heavily upon fall (Siniff and Ralls 1991); whereas, in preimplantation period in this female adequate usage of stored genetic mate- the Monterey area, seasonal trends in lasted for 3 months. With the addition rial through assisted reproductive pupping are less pronounced (Riedrnan of more females to the dataset, it may be technologies such as artificial insemi- et al. 1994). Females return to estrus 1 possible to fully characterize the period nation, in vitro fertilization, and embryo day to several weeks after pup weaning. of delayed implantation in sea otters. transfer. Successful assisted reproduc- Interestingly, females that lose their Additionally, fecal cortisol metabolites tive technology, however, relies on pups prematurely soon return to es- also have been monitored successfully knowledge of species-specific repro- trus; thus, spring pupping mortality and show promise as an index of physi- ductive characteristics, including annual and subsequent mating may account ological stress in this species. reproductive cycles, seminal traits, and for the second pupping peak in the timing of ovulation. Therefore, practi- fall. Estrus length, based on pair-

58 Endangered Specks UPDATE Vol. 13 No. 12 1996 Male reproduction tember through November, and copula- of reproduction in the male sea otter In contrast to female sea otters, tion occurs exclusively in the water needs to be conducted. limited information is available about (Riedman and Estes 1990). Only one the reproductive biology of male Cali- report documents ejaculate traits in sea Conclusion and fornia sea otters. Male Alaskan sea otters (Ballachey 1995); this study was recommendations otters reach sexual maturity at 5-6 years conducted to assess damage in male Present realities require focusing of age (Schneider 1978;Garshelis 1983); Alaskan sea otters after the 1989 Exxon on basic research to determine critical however, the onset of sexual maturity in Valdez oil spill in Prince William Sound. reproductiveparameters for both female California males has not been estab- Overall, ejaculates from adult male sea and male seaotters, including the timing lished (Riedman and Estes 1990). otters exhibited low sperm concentra- of ovulation, number of normal sperm Reproductive tracts from "old" (exhib- tions and contained an average of only produced and optimal methods for iting well-worn teeth) Alaskan males 13.8% morphologically normal sperm cryopreserving sperm, before attempting show no signs of diminished sperm pro- cells per ejaculate. The most preva- artificial breeding or long-term storage duction (Kenyon 1969). It also has been lent structural defects included of genetic material. Ideally, protocols suggested that Alaskan males produce mid-piece and tail abnormalities. for ovulationdetection, semen collection sperm throughout the year (Lensink More alarming, however, is the fact and artificialinsemination are developed 1962); however, testicular histology that high numbers of abnormal sperm using a model species before applying indicates that a mild periodicity is asso- were found in both oiled and unoiled the technology to the endangered ciated with spermatogenesis (Kenyon (control) males, indicating that this species. This approach has been 1969). In California, mating activity of may be characteristic of the species. successful for a critically-endangered territorial males increases during Sep- It is clear that a comprehensive study mustelid species, the black-footedferret (Mustela nigripes). Semen cryopreservation and - 30 artificial insemination techniques were developed first for the domestic ferret - 20 (Mustela putorius furo; Howard et al. 1991). i I. il0 Determining optimal 400 8 methodology in the model species enabled the production of black-footed ferret offspring by artificial insemination with frozen- h h 300 thawed sperm (Howard et 0 e' \ al. 1996). For the sea otter, 0 3 C Total E nglg Y the non-threatened Alaskan V - W n subspecies would be an I excellent model for the C, 200 4 threatened Californian cO subspecies. Additionally, the relative abundance of Alaskan sea otters in captivity provides a unique 100 2 opportunity to develop these technologies for use in the field without disturbing wild populations. 0 GRBs, in combination 0 with assisted reproductive -180 -120 -90 0 30 60 90 -150 -60 -30 120 150 technology, have enormous Day from Estrogen Surge potential for conserving en- dangered species. There is a Figure 2. Total estrogen (E = estradiol and estrone) and progestins (P = progesterone metabolites) general consensus that concentrations (per gram of dry fecal weight) across a full year of fecal samples from a single female GRBs will be contributing sea otter at the Seattle Aquarium. Day 0 reflects the time of the estrogen spike which, for this female, occurred in January. Estrus behavior refers to overt and frequent female-initiated matlng behavlor with significmtl~to the cmser- the male. This behavior was observed only during the single event indicated on the graph. vation of rare wildlife

Voi. 13 No. 12 1996 Endangered Species UPDATE 59 species as we enter the 21st century Literature Cited Final Report. 45 pp. (Wildt 1992). For the California sea AZA Genome Resource Banking Advisory SinhaA.A. and C.H. Conaway. 1968. Theovary otter, the availability of stored gamete Group. 1996. Draft genome resource bank- of the sea otter. Anatomical Record 160:795- ing resource guide. 806. andlor embryo samples is particularly Ballachey, B. E. 1995. Biomarkers of damage to Sinha A. A., C. H. Conaway, and K. W. Kenyon. relevant in the event that the current sea otters in Prince William Sound, Alaska, 1966. Reproduction in the female sea otter. population experiences a drastic decline following potential exposure to oil spilled Journal of Wildlife Management 30: 12 1- in number. Storing gamete samples, from the Exron Valdez. Exvon Valdez Oil 130. Spill StateFederal Natural Damage Assess- Siniff D. B. and K. Ralls. 1991. Reproduction, however, should not be viewed as the ment Final Report (Marine Mammal Study survival and tag loss in California sea otters. solution to sea otter conservation, but 6-1). U.S. Fish and Wildlife Service, An- Marine Mammal Science 7:211-299. rather as one of many tools that will chorage, Alaska. U.S. Fish and Wildlife Service. 1996. Southern enable this species to thrive. All rea- Bodkin J. L., D. M. Mulcahy, and C. J. Lensink. seaotterrecovery plan, 1996 draft. Ventura, 1993. Age-specific reproduction in female California. 41 pp. sonable approaches should be explored sea otters (Enhydra lutris) from South Cen- Wendell F. E., J. A. Ames, and R.A. Hardy. and used to help conserve and under- tral Alaska: analysis of reproductive tracts. 1984. Pup dependency period and length of stand the California sea otter while Canadian Journal of Zoology 71: 18 11 - 18 15. reproductive cycle: estimates from observa- maximizing the efficient use of limited Frankham R. 1995. Inbreeding and extinc- tions of tagged sea otters, Enhydra lutris, in tion: a threshold effect. Conservation California. California Fish and Game De- resources. Biology 9:792-799. partment 70:89-100. For wildlife populations that are Garshelis D. L. 1983. Ecology of sea otter in Wildt D. E. 1989. Strategies for the practical susceptible to catastrophe, an organized Prince William Sound, Alaska. Ph.D. the- application of reproductive technologies to endangered species. Zoo Biology Supple- effort to collect, evaluate, cryopreserve, sis, University of Minnesota, Minneapolis, Minnesota. 321 pp. ment 1:17-20. store and use germ plasm should rank Howard J. G., M. Bush, C. Morton, F. Morton, Wildt D. E. 1992. Genetic resource banks for high on the list of conservation priori- K. Wentzel, and D. E. Wildt. 1991. Compara- conserving wildlife species: justification, ties. Because of the likelihood that an tive semen cryopreservation in ferrets examples, and becoming organized on a oil spill could dramatically affect the (Mustelaputorius furo) and pregnancies after global basis. Animal Reproductive Science laparoscopic intrauterine insemination with 28:247-257. California sea otter population, there is frozen-thawed semen. Journal of Reproduc- Wildt D.E., U.S. Seal, and W.F. Rall. 1993. an urgent need to establish a GRB be- tive Fertility 92: 109-118. Genetic resource banks and reproductive tech- fore such a crisis occurs. Development Howard J. G., D. R. Kwakowski, E. S. Will- nology for wildlife conservation. Pages 159-173 in J.G. Cloud and G.H. Thorgaard, of GRB will require a concerted effort iams, R. W. Atherton, R. M. Kitchin, E. T. Throne, M. Bush, and D.E. Wildt. 1996. editors. Genetic conservation of salmonid from aquariums, reproductive biolo- Pregnancies in black-footed ferrets and Si- fishes. Plenum Press, New York, New York. gists, field biologists and policy-makers, berian polecats after laparoscopic artificial as well as funding commitments. In insemination with fresh and frozen-thawed summary, the following reproductive semen. Journal of Andrology 17 (Supp1ement):P-5 1. studies are recommended to facilitate Jameson R. J. and A. M. Johnson. 1993. Repro- the development of a GRB: (1) conduct ductive characteristics of female sea otters. a comprehensive study on male repro- Marine Mammal Science 9: 156-167. duction that characterizes ejaculate traits Kenyon K. W. 1969. The sea otter in the eastern pacific ocean. North American and seasonality; (2) determine unknown Fauna Number 68.352 pp. aspects of female sea otter endocrinol- Lensink C. J. 1962. The history and status of ogy, including estrous cycle length, sea otters in Alaska. Ph.D. thesis, Purdue timing of ovulation and seasonality; and University, West LaFayette, Indianapolis, Indiana. 188 pp. (3) develop semen handling and Mazur, P. 1984. Freezing of cells: mecha- cryopreservationprotocols. Because of nisms and implications. American Journal the precarious status of the California of Physiology 247:C125-C142. sea otter, these reproductive studies Riedman M. L. and J. A. Estes. 1990. The sea otter (Enhydra lutris): behavior, ecology should be initiated as quickly as pos- and natural history. U.S. Department of the sible. A GRB, together with Interior, Fish and Wildlife Service. Bio- conservation activities such as im- logical Report 90(14). 126 pp. proved pollution control, diligent Riedman M. L., J. A. Estes, M. M. Staedler, A. A. Giles, and D. R. Carlson. 1994. Breed- habitat maintenance and protection, ing patterns and reproductive success of captive breedinglreintroduction pro- California sea otters. Journal of Wildlife grams and public awareness Management S8:39 1-399. campaigns, promises to be an effec- Schneider K. B. 1973. Age determination of sea otters. Alaska Department of Fish and tive strategy for conserving the Game, Federal Aid in Wildlife Restoration California sea otter. Projects W-17-4 and W-17-5, Progress Julie Long can be reached at Riverbanks Report. 23 pp. Zoological Park and Botanical Garden Columbia, Schneider K. B. 1978. Sex and age segrega- SC 29210. Shawn Larson works with the Seattle tion of sea otters. Alaska Department of Aquarium, Seattle, WA98101-2059. Sam Wasser Fish and Game. Federal Aid in Wildlife is with the Center for Wildlife Conservation, Restoration Projects W-17-4 and W-17-5, Seattle, WA 98103-5897.

60 Endangered Species UPDATE Vol. 13 No, 12 1996 Sea Otters in Captivity: The Need for Coordinated Management as a Conservation Strategy E. Jean Brennan and John Houck Sea otters in captivity serve an collect sea otters from the wild to fill modify the captive management important role in conservation, their exhibits (Soult 1980; Foose 1980; program in an effort to enhance the specifically in the education of the public Wildt et al. 1991). Realizing this contribution the captive sea otter and the maintenance of biological potential will challenge animal population can make in the conservation diversity. Historically, education has husbandry techniques (see Long et al., of this species. been the primary focus. This is because this issue) but, more importantly, will many aquariums adopt a regional require a change in captive History in captivity and husbandry approach to both their exhibit collection management philosophy (i.e., to requirements and interpretive programs, and use the manage the captive sea otters In the 1930s and 1940s, Russian sea otter to teach the visitor about local cooperatively rather than investigators were the first to identify coastal habitats. In the last decade more independently, which has historically critical physiological requirements and aquariums have tried to educate the been the practice). basic husbandry techniques required to public about broader conservation The management of the captive sea successfully meet those requirements issues; for example, the effects of over- otter population must be directed toward in captivity (Barabash-Nikiforov1947). harvesting by commercial and sport anticipating the need to respond to Their findings were later corroborated fisheries, and the effects of human- environmental or human-caused threats by U.S. investigators in Alaska during caused environmental disasters such as to the wild population. The primary the 1950s (Kenyon 1969). The most oil spills. Aquariums have the potential, objective therefore must be to preserve critical requirements reflect the animal's however, to play a more active role in within the captive population an unique physiological and behavioral sea otter conservation by linking the adequate representation of the genetic adaptations to the cold marine management of the captive population diversity and presumably the adaptive environment (Kirkpatrick et al. 1955; with the conservation needs of the wild traits that are found in the wild Kenyon 1969),specifically, the fact that population. This would require that the population (Foose 1980). Our success the sea otter, unlike other marine captive population be genetically and at achieving that objective can be mammals, lacks a fat or blubber layer to demographically managed to form a measured with the use of computer insulateitfromcoldwatertemperatures. self-sustained population. The creation simulations that model the trends in The animal relies on its fur which must of a genetically healthy and stable the population under various be clean and well-groomed if it is to be captive population would serve, not only management strategies. In this paper effective at trapping a layer of air next to asageneticreservoirtouseinpopulation we present the results of such an its skin, thus preventing the cold ocean recovery or restoration attempts in the analysis and, based on the sensitivity water from penetrating to the skin. To wild, but also to eliminate the need to of the model, we identify ways to prevent the breakdown of the natural oils in the fur, the sea otter must have 20 - access to large quantities of clean sea 18 -- water maintained at a cool 1 16 -- temperature. Without these essential a3 5 14-- elements provided in the captive environment, the fur cannot be 5 12-- -- maintained and the animal quickly It 10 becomes hypothermic and dies. The f -- t: 8 animal also relies on its high metabolic 0 m 6 -- rate to generate heat internally to help 4-- maintain core body temperature. This Y 2-- requirement demands that a sea otter

,I,Il I I I , I I , I,III, receives large quantities of food, 0 - 111111111111111111111111,1111 4 approximately 20% of its body 1955 1958 1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 weight per day, at an annual cost of Year $10-14,000. The first sea otter to be success- Figure 1. Chronological history showing the number and year wild Alaska sea otters joined the North America captive sea otter population. Figure does not include animals that died in a public within the first month after capture. was housed for six years at the Wood-

Vol. 13 No. 12 1996 Endangered Species UPDATE 61 land Park Zoo in Seattle, beginning in collected by commercial animal dealers subpopulation due to the large number 1955 (Vincenzi 1962). Since then, the for aquarium exhibits, and are hunted of same-age animals that enter captivity professional staff and associates work- by native-peoplesunder state and federal at random intervals. This is particularly ing in zoos and aquarium have worked permits. The California sea otter evident as a result of the 1989 oil spill to improve husbandry techniques population has been designated (see Figure 1). The age-structure of the (Johnson et al. 1967; Pollard 1969; threatened under the Endangered Alaska subpopulation follows: females Johnson 1972; Nightingale 1981; Gla- Species Act due to its small numbers, (2 yr. n=l; 6 yr. n=l; 7 yr. n=7; 8 yr. zier 1984; Rarnirez et al. 1996; Powell slow growth rate, and risk of oil spills n=3; 12 yr. n=l; 16 yr. n=2; 17 yr. n=l; 1994) and to learn more about sea otter (U.S. Fish and Wildlife Service 1996). 18 yr. n=l; 25 yr. n=l) and males (6 yr. behavior (Kenyon 1969; Whitt 1971), Currently there are 24 Alaska sea otters n=l; 7yr. n=2; 13 yr. n=l; 17 yr. n=l). nutrition (Crandall 1964; Mattison and maintained in aquariums in North Continued reliance on punctuated Hubbard 1969; Nightingale et al. 1978, America, 113 in Japan, and two in recruitment is unreliable, perpetuates 1979; Hoffer 1973; Fausett 1976; Europe. There are only thirteen the unstable age-structure and thus Antonelis et al. 1981; Williams et al. members of the California subspecies hinders the ability to form a 1991), reproduction (Brosseau et al. in four U.S. aquariums, all of whom demographically stable, self-sustaining 1975; Jameson et al. 1975; Antrim and were rescued as stranded orphaned pups population. This pattern is exacerbated Cornell 1980; Hewlett 1983; Casson et that would otherwise have died. by the low recruitment level due, in al. 1987; Nakajima et al. 1988; Hanson California sea otters are not exhibited part, to the practice of transferring et al. 1993), and health (Kenyon et al. 1965; Stetzer et al. 1981; Giddens et al. Probabilitv of female ~roduciu~1 DUP 33 1984;Williams 1986,1990;Joseph and I 1 1 Spraker 1989; Williams et al. 1990; [ Probability of female produciug 2 pups 1 1.5 I Casson 1990; Brown et al. 1994). Inte- I Sex ratio at birth (males) 1 0.6 I grating these findings into exhibit de- Female mortality (0- 1yr of age) 0.727 sign results in an exhibit that is very Female mortahty (1-2 yr of age) 0 costly to build and to maintain, due to Female mortality (2-3 yr of age) 0.5 the sophisticated sea water systems and Female mortality (adult, 3-25) 0.091 high level of filtration required. As a Male mortality (0- 1 yr of age) 0.5 result, the number of "homes" in captiv- I Male mortalitv (1-2 vr of age) I 0 I ity, defined as the captive carrying ca- Male mortality (2-3 yr of age) 0 pacity, has been very limited. This Male mortality (adult, 3-25) 0.099 has forced captive managers to limit Table 1. Life history rates of sea otters in captivity. captive reproduction (or even prevent breeding entirely), and to transfer cap- outside the U.S. and their export is captive-born Alaska sea otters out of tive-born offspring to Japan or Eu- prohibited due to their threatened the breeding population. Fifty percent rope due to' space limitations. Based status. In this paper we refer to the of the captive-born offspring that survive on a recent meeting among members collective captive members of each their first year have been sent to of the captive zoo and aquarium com- subspecies as a "subpopulation" of aquariums in Japan. The current Alaska munity in May of 1996, it is estimated the entire captive sea otter population subpopulation represents 10 wild- that the North American carrying ca- in North America. caught, 11non-releasable wild seaotters pacity will not exceed 47 over the next Since 1955, a total of 92 Alaska sea rescued during the Exxon Valdez oil five years. otters have been exhibited in North spill (one is a castrated male), and three America zoos and aquariums, of which captive-born. Only two of the five Population status and life history 30 were wild-caught, 22 were non-re- institutions that maintain Alaska sea data of sea otters in captivity leasable wild sea otters placed in cap- otters in North America are attempting Two recognized subspecies, tivity following the Exron Valdez oil to breed their animals (representing commonly referred to as Alaska spill of 1989, and 44 were captive-born. wild-caught females and two captive- (Enhydra lutris kenyoni) and California Five of the wild sea otters died withm born males). (E. 1. nereis) sea otters, are managed by one month of their arrival in captivity An analysis of the historic records wildlife agencies in North America; both (these are not included in the demo- was used to calculate life history data are exhibited in aquariums. There are graphic calculations presented in this for Alaska sea otters in captivity (see more than 150,000 Alaska sea otters in paper). Alaska sea otters have gener- Table 1). Annual survival rates were the wild (Riedman and Estes 1990), in ally come into captivity from the wild as calculated using all available survival contrast to the estimated 2,400 in a result of environmental disasters or data from dead, living, and transferred California (U.S. Fish and Wildlife failed translocation efforts (Hewlett sea otters. Adult mortality are more Service 1996). The Alaska population 1983). The result has been the forma- commonly observed in males between is secure in the wild, its members are tion of an unstable age-structure of this the ages of 10 to 13, and females be-

62 Endangered Species UPDATE Vol. 13 No. 12 1996 litter size, sex determination,death) and assigns the outcome of each step based on observed probabilities. Each simu- lation was repeated 1,000 times. The results of these simulations predict the most probable outcome and demo- graphic trends in both the Alaska and California sea otter subpopulations through the year 2020. It should be noted, however, that the model assumes coordinated, coop- erative management to maximize re- Table 2. Assigned values used in VortexO model. productive output and genetic founder representation and to minimize inbreed- tween the ages of 13 to 18. The longest however, none of these pups survived ing(i.e.,unrestrictedmovementbetween lived animal is still alive at age 25 yr., (see Duffield et al., this issue). The institutions). Currentmanagementprac- which exceeds the previous longevity oldest California female in captivity is tices violate the model's assumptions records of 23 in females and 18 in males. 12 years of age. A complete historic however because many aquariums limit Reproductive rates were calculated us- record for California sea otters has not or prevent reproduction and rarely ex- ing the historic records of 17 reproduc- been assembled, thus it is not possible change animals because they operate tive-aged females: 12 produced a total to compare life history traits of the two independently. Thus, the actual popu- of 40 single pups, one produced twins, subpopulations. There are currently 13 lation numbers will be less than those and four were non-reproductive. The California sea otters maintained in four predicted in the simulations presented. first female sea otter to be successfully U.S. aquariums, representing the The results, therefore, are presented as maintained in captivity was not included following- age-structure:- females (1 yr. a heuristic tool, to help evaluate how in our reproductive rate estimates due to n=2; 2 yr. n= 1; 3 yr. n= 1; 4 yr. n=l ; 12 management strategies may influence abnormal reproductive tract develop- yr. n=2) and males (2 yr. n=1; 3 yr. n=l; population trends, not to predict exact ment (Vincenzi 1962). The youngest 4 yr. n=2; 5 yr. n=l; 10 yr. n=l). numbers in any given year. The results female to reproduce was 3 years old of these simulations are presented when the pup was born, and the oldest Population viability analysis and graphically in Figures 2-4. was 12. The sex ratio of captive-births management options is slightly biased towards males (0.6). We present the results of computer Observed annual female reproduction simulations that model in this study equal 0.34, with a lifetime demographic and re- 35 T average of 2.65 (range 1-8 pupslfemale). productive outcome as These rates should be considered a pro- a measure of the cap- duction measure rather than a measure tive population's long- of female reproductive potential how- term viability under 25 ever, since managers have the option to current management limit captive breeding. In the wild, praps. The Vor- 20 -- Alaska sea otters exhibit higher repro- tex Monte Carlo ductive rates (see Bodkin and Ballachey, computerprogramwas 15 -- this issue). used for this purpose California sea otters have been (see Table 2) (Lacy and 10 -- maintained in captivity since 1969. Kreeger 1992;Lacy, in Complete records are available for a press). The age-struc- 5 -- total of 32 animals, exhibited in four ture of the starting aquariums. Twelve were wild-caught, population matched 0 t;~t;~;;;;;;;;ll;;;;i;l 18 were rescued from the wild as the current profile of 1 3 5 7 9 11 13 15 17 19 21 23 orphaned pups (Harrold et al. 1996), each subpopulation. Year and two were conceived in the wild but The model generates a Figure2. Most probableoutcornebased on computer simulations born in captivity. Eighteen additional Lesliematrixusingthe of the captive Alaska sea otters in North America under three captive-born California sea otters were observed life history different management strategies: [circle] continueto limitfemale born at one institution as the result of data, simulates a se- reproductionandtransferhat of theoffspring out of the breeding breeding between eight females and a ries ofsteps that repre- population; [square] continue to limit female reproduction but keep all captiveborn offspring in the breeding population; single male. Due to chromosomal sent events in the life [triangle] double reproductive rate while retaining all captive abnormalitiesfound in the breeding male cycle (reproduction, born offspring in the breeding population.

Vo1.13 No. 12 1996 Endangered Species UPDATE 63 Modeling the Alaska subpopulation The Alaska subpopulation was modeled under a variety of management scenarios. The first examinedthe effects of adding wild-caught adults (1 male and 6 females, ages 3 years old) every other year for 10 years to the captive subpopulation. A second simulated the possible effects of adding alarge number of same aged animals (3 males and 10 females, ages 3 yr. old) to the population at year two of the simulation (i.e., to simulate the possible effects of another Year major oil spill). In both cases, the simulations failed to produce a stable Figure 3. Most probable outcome of computer slmulations of the population. The only way a stable captive California sea otters in North America under four different population was achieved, relying on management strategies: [diamond] continue to manage as a non- reproductive population; [square] female reproductive rate equal supplementing the population with wild- to that obsenred in the Alaska subpopulation; [triangle] double caught sea otters, required a population female reproductive rate while adding two yearling females every size so large it was meaningless (given year for seven years; [cross]double female reproductive rate while the current and anticipated carrying adding two yearling females every year for 15 years. capacity in North American aquariums). values observed in the captive Alaska optimizing the conservation value of Several other, more realistic, sea otters since specific data for limited carrying capacity. This management strategies were simulated: California sea otters are lacking. Four represents a shift in management (1) continue the current practice of different management strategies were philosophy in recognition of the threat limiting female reproduction and simulated: (1) continue the current to the wild California population, and transferring half of the captive-born practice of non-reproductive the fact that Alaska sea otters are offspring out of the population; (2) management; (2) encourage female adequately represented in aquariums in continue to limit female reproduction reproduction to achieve the same level Japan and in the wild. In this strategy, but allow all captive-born offspring to as observed in the Alaska female; (3) the Alaska sea otters currently in the remain in the breeding population; and double the female reproductive rate and U.S. would be replaced with California (3) encourage female reproduction, add two wild year-old orphan females sea otters as they age and die. It is doubling the rate, and allow offspring to to the captive population each year for 7 important to remember that the Alaska remain in the breeding population. years; and (4) double the female sea otters in captivity serve as the Figure 2 show the results of these reproductive rate and add two wild year- biological model to use in studying and simulations. Despite the feasibility in old orphan females to the captive refining captive reproductive implementation, these management population each year for 15 years. techniques. Thus, reproduction of strategies failed to produce a self- Again, because current management Alaska sea otters need not necessarily sustained population. The results, practices violate many of the model's be eliminated, but rather be controlled however, help to illustrate: (a) that the assumptions, the choices of 7 and 15 to produce surplus animals only if they model is sensitive to an increase in years and supplementing with only are guaranteed to be transferred out of reproductive output (whether it be females is intended to be illustrative, the U.S. breeding population. This through increase reproductive rate or not prescriptive. The simulation results functionally represents a zero increase recruitment); (b) that captive further illustrate the need to increase reproductive rate. The California breeding alone does not produce the reproductive output in captivity and to subpopulationwould be simultaneously level of recruitment to maintain the supplement the captive population with managed to increase its reproductive Alaska subpopulation (presumably due animals from the wild before a self- output while adding orphaned animals to the unstable age-structure); and (c) sustaining population can be achieved. to the captive breeding population until continued reliance on infrequent and a self-sustaining population could be unreliable events to provide additional Shifting the emphasis over time to established. replacement animals will further hinder manage a single subspecies in U.S. the process of becoming self-sustaining. Figure 4 illustrates one possible Conclusions and strategy: to simultaneouslymanage both recommendations Modeling the California subpopulation subpopulations while over time shifting The results of computer modeling Figure 3 presents the simulation to manage a single subpopulation. The indicate that current management results of the captive California overall goal would be to maintain only practices (i.e., limited reproduction, subpopulation. We used the life history California sea otters as a way of limited recruitment, and restricted

64 Endangered Species UPDATE Vol. 13 No. 12 1996 inbreeding. This is an unlikely explanation in the case of captive Alaska sea otters, however, since the majority of the recorded births have been between wild, presumably unrelated pairs. Captive managers should therefore examine husbandry and management practices that may contribute to pup mortality such as: (a) conditions under which the parents were reared (especially in the case of sea otters that were acquired as stranded orphan pups); (b) stressful environmental factors such as those produced by the sight and 1 3 5 7 9 11 13 15 17 19 21 23 sounds of human activities (Brosseau et Year al. 1975; Antrim and Cornell 1980; Figure 4. Graphic illustration of a management strategy to exhibit both Nightingale 1981 ; Graham and Hewlett Alaskaand Californiaseaotters in North America whilegraduallyreplacing 1988); (c) sexual receptivity as a Alaska sea otters with California sea otters. function of social groupings; and (d) exchange of animals between capacity prohibits breeding.) In order how potential mates are introduced to institutions) will fail to produce a self- to realize this latter approach, aquariums one another for mating (Graham and sustaining population. Based on a are encouraged to support studies of Hewlett 1988). popula 'on viability analysis using both male and female reproductive (3) Link the captive population Vortex,8 the carrying capacity in North biology and behavior, to initiate the with the problem of stranded California America is too limited to maintain collection of semen, and to promote pups. As in the case of the Alaska sea members of both the Alaska and studies to optimize cryopreservation otter population, it will be necessary to California subspecies without relying and utilization of this material (see Long supplement the captive California on replacement animals from the wild. et al., this issue). population with additional animals from The following recommendations are (2) Increase reproductive and the wild until a demographically stable offered to help zoos and aquariums make survival rates. Reversing the projected age-structure is established. The a more significant contribution to sea decline in the captive North America difference between the Alaska and otter conservation. sea otter population will require a California sea otter subpopulations is (1) Increase carrying capacity. coordinated management effort to the predictable supply of animals from Efforts to increase the carrying capacity increase the number of females that are the wild, due to the number of orphan through the construction of new sea allowed to breed, increase annual pups that strand each year. In 1986, the otter exhibits will be minimal due to the recruitment and, over the next few Monterey Bay Aquarium in central high exhibit construction and annual decades, supplement the captive California began efforts to raise stranded animal maintenance costs. Certainly population with animals from the wild. sea otter pups for release back into the zoos and aquariums may be more willing Reproductive rates can be increased in wild as a humane endeavor. Not every to dedicate exhibit space to California two ways: by increasing the number of animal could be successfully sea otters if it promotes their females that reproduce, and by rehabilitated, and those that were conservation mission. Institutions that increasing the survival rates of the deemed non-releasable have been added decide to build new sea otters exhibits offspring. Every effort should be made to the captive population. Historically, should be encouraged to maintain to house captive sea otters in the number of pups that are orphaned California seaotters. In addition, several reproductive groups and to manage the each year ranges from two to eight (see steps may be taken to increase captive animals to facilitatebreeding. Currently, Figure 5). As a result, the captive carrying capacity including: (a) only twq of the four institutions that California subpopulation has a more encourage institutions to increase the maintain California sea otters in stable age-structure because of this carrying capacity of their existing reproductive breeding groups annual recruitment. Adopting a strategy facilities; (b) explore the feasibility of (representing five wild females and to incorporate orphaned pups into the exhibiting sea otters with other marine two wild males), and none have captive population, or to preferentially mammals in mixed species exhibits; reproduced. select animals to establish a self- and (c) support cryopreservation and Increasing annual recruitment can sustaining captive sea otter population assisted reproductive efforts. (This be achieved by decreasing pup mortality. would not prohibit rehabilitation efforts would allow the introduction of genetic High infant mortality has been reported since the number in need of rehabilitation materials into the gene pool at a future in other captive species (e.g., Ralls et al. exceeds the number of spaces in time if the current limited carrying 1979,1980) and are often attributed to captivity. It is theU.S. Fish and Wildlife

Vol. 13 No. 12 1996 Endangered Species UPDATE 65 Service recommendation that orphan prompt such a meeting. type of permit must be written jointly if pups remain on the beach. These animals (5)Work on an international scale. the relevant issues and obstacles are to will undoubtedly die. Thus, placing A closer working relationship between be identified and addressed. The permit such animals in captivity has no impact country representatives will greatly would clearly identify the various on the population's natural recovery in facilitate the transfer of surplus captive- management options and would grant the wild. born Alaska sea otters pups, provide captive managers the latitude to work (4) Utilize the existing infrastruc- captive homes to stranded or non- more quickly and effectively. Captive ture to implement management objec- releasable sea otters in the event of managers should therefore consider tives. Many of the key elements and another major oil spill off the Alaska working with the U.S. Fish and organizational structure needed to de- coastline, and would minimize the Wildlife Service in this endeavor to sign and implement a more active sea need to collect Alaska sea otters from be their highest priority because it otter conservation program are already the wild. Improved communication will serve as the legal foundation upon in place. Eight of the nine North Arneri- outside of North America, especially which to build the captive management can institutions currently exhibiting sea between the U.S., Canada, and Japan, is program. otters are fully accredited members of needed. the American Zoo and Aquarium Asso- (6) Work closely with federal Literature Cited ciation (MA), a professional organiza- agencies. Captive managers need to Antonelis, G.A., Jr., S. Leatherwood, L.H. tion that promotes cooperative efforts workmore closely with federal agencies Cornell, and J.G. Antrim. 1981. Activity cycle and foodselectionof captive seaotters. among its member institutions to effec- to identify ways aquariums can best The Murrelet 62:6-9. tively manage species in need of con- serve sea otter conservation. Aquarium Antrim, J.E., and L.H. Cornell. 1980. servation efforts. One of the principle professionals are already working with Reproduction of the sea otter (Enhydra lutris) mechanisms of fostering cooperative the U.S. Department of Agriculture in a in captivity. International Zoo Yearbook 20:76-80. efforts is the Taxon Advisory Group method known as "negotiated Barabash-Nikiforov, 1.1. 1947. Kalan. Pages (TAG), a group composed of experts rulemaking" to update and upgrade 1-174 in Soviet Ministrov RSFSR. Glavnoe that are knowledgeable about the par- standards for the display and care of sea upravlenie po zapovednikam. [The sea otter. ticular group of animals. The AZA otters on public display. A similar Translated from Russian by A. Birron and Z.S. Cole for the National Science Marine Mammal TAG has already been approach should be adopted between Foundation by the Israel Program for formed, and regional studbooks, which the captive community and the U.S. Scientific Translations, Jerusalem, Israel. provide a complete demographicanaly- Fish and Wildlife Service. Their 1962. 227 pp.]. sis of the historic and living population, common goal should be to enhance the Brosseau, C.,M. L. Johnson, andK. W. Kenyon. 1975. Breeding the seaotter (Enhydra lutris) already exist for sea otters in North captive breeding program, and the at the Tacoma Aquarium. International Zoo America and Japan. We recommend transfer and management of California Yearbook 15: 144-147. that the industry professionals meet and sea otters to maximize and retain genetic Brown, S.R., M. Glenn, and S.R. Libra. 1994. identify common goals, define man- diversity. The legal tool that would Case report: perivular uroliths in the Alaska sea otter. Proceedings 25Ih IAAAM agement objectives, and to constantly facilitate this level of coordinated Conference, Vallejo, California. Pages 16-20. measure their success in achieving management is an enhancement permit Casson, C.J. 1990. Administering oral conservation goals. Hopefully, the (U.S. Fish and Wildlife Service,Ventura medications to captive sea otters (Enhydra results presented in this paper will Office, personal communication). This lutris).Proceedings 18" International Marine Animal Trainers Association Conference, Chicago, Illinois. Pages 12- 19. Casson. C.J., B. Anderson, and J.W. Nightingale. 1987. A descriptive analysis of nursing in captive born Alaskan sea otters. Proceedings American Association of Zoological Parks and Aquariums Conference, Portland, Oregon. Pages 490-500. Crandall, L.S. 1964. Sea otters. Pages 345-348 in L. S. Crandall. Management of wild mammals in captivity. University of Chicago Press, Chicago, Illinois. 761 pp. Fausett, L.L. 1976. Assimilation efficiency of captive sea otters. M.S. thesis, University of California, Long Beach, California. 39 pp. Foose, T.J. 1980. Demographic management of endangered species in captivity. International Zoo Yearbook 20:154- 166. 1986 1988 1990 1992 1994 1996 Giddens, W.E., M. Ryland, T.A. Gornall, and C. J. Casson. 1984. Idiopatic scoliosis Year in a newborn sea otter, (Enhydra lutris). Journal of Wildlife Diseases 20(3):248-250. Figure 5. Chronological history of stranded California sea otter pups: [white] number that Glazier, R. J. 1984. Sea otters: delight or stranded; [black] number of non-releasable pups that were added to the captive population. dilemma. Proceedings American

66 Endangered Species UPDATE Vol. 13 No. 12 1996 Association of Zoological Parks and Nightingale, J. W. 1981. Essential elements of an overview, a strategy, a draft policy Aquariums Conference, Miami, Florida. a successful breeding program with captive statement and background documentation. Pages 237-241. sea otters. Proceedings American Zoo Vet (Singapore). IUCNISSC Conservation Graham, M. and K. G. Hewlett. 1988. The Association Conference, Seattle, Breeding Specialist Group Publication. biology of the Northern sea otters at the Washington. Pages 84-86. Apple Valley, Minnesota. Vancouver Aquarium. Proceedings American Nightingale, J. W., H. D. Kemper, and J. P. Williams, T. D. 1986. Mustelidae (sea otter). Association of Zoological Parks and Sty ers. 1978. A computer-ready record Pages 820-822 in M. E. Fowler, editor. Zoo Aquariums Regional Conference, Monterey, system for storage and correlation of and wild animal medicine, 2"* edition. California. Pages 218-222. nutritional and other husbandry data. Philadelphia, Pennsylvania. 1127 pp. Hanson,M. B.,L. J. Bledsoe,B. C. Kirkvold, C. Proceedings American Association of Williams, T. D. 1990. Sea otter biology and J. Casson, and J. W. Nightingale. 1993. Zoological Parks and Aquariums medicine. Pages 625-648 in L. A. Dietrauf, Behavioral budgets of captive sea otter Conference, Denver, Colorado. Pages 197- editor. Handbook of marine mammal mother-pup pairs during pup development. 202. medicine: Health disease and rehabilitation. Zoo Biology 12:459-477. Nightingale, J. W., C. Timmis, and J. Styers. CRC Press, Boca Raton, Florida. 735 pp. Harrold, C., E. J. Brennan, T. Williams, M. 1979. Food preference studies with captive Williams, T.D., D.M. Baylis, S.H. Downey, Staedler, and J. Hymer. 1996. The California sea otters (Enhydra lutris) using a and R.O. Clark. 1990. A physical restraint sea otter: changing needs and challenges. comparison matrix. 3* Biennial Conference device for sea otters. Journal of Zoo and Proceedings 4th International Aquarium of the Biology of Marine Mammals, Seattle, Wildlife Medicine 21(1):105-107. Congress, Tokyo, Japan (in press). Washington. Page 64. Williams, T. D., L. Henderson, P. Harr, J. Hewlett, S. 1983. A decade of sea otters Pollard, R. J. 1969. Notes on the husbandry and Hymer, and G. Issvoran. 1991. Nutritional (Enhydra lutris). Proceedings American behavior of the sea otter in captivity. requirements of the sea otter (Enhydra Association of Zoological Parks and Proceedings 6th Annual Conference on lutris). Proceedings 22"* IAAAM Aquariums Conference, Vancouver, British Biological Sonar and Diving Mammals, Conference, Marine Land, Florida. Page 61. Columbia. Pages 224-228. Stanford Research Institute. Palo Alto, Hoffer, S.A. 1973. Sea otters in captivity. Sea California. Pages 95-98. Frontiers, (May-June). Pages 141-147. Powell, D. 1994. A multispecies exhibit for the Jameson, R.J., A.M. Johnson, andK.W. Kenyon. southern sea otter (Enhydra lutris). 1975. Maternal behavior and pup ontogeny Proceedings of Annual American Zoo and of captive sea otters. Proceedings 1"Biennial Aquarium Association Conference, Atlanta, Conference on Marine Mammals. SantaCruz, Georgia. Pages 229-23 1. California. Page 41. Ralls, K., K. Brugger, and J. Ballou. 1979. Johnson, M.L. 1972. The sea otter in captivity. Inbreeding and juvenile mortality in small Pages 17-24 in A. Seed, editor. Sea otter in populations of ungulates. Science 206: 1101- eastern North Pacific waters. Pacific Search. 1103. 37 PP. Ralls, K., K. Brugger, and A. Glick. 1980. Johnson, M. L., K. W. Kenyon, and C. Brosseau. Deleterious effects of inbreeding in a herd 1967. Notes on a captive sea otter, (Enhydra of captive Dorcas gazelle. International Zoo lutris). Internationalzoo Yearbook7:208-209. Yearbook 20:137-146. Joseph, B.E. and T.R. Spraker. 1989. Acute fatal Ramirez, K., M. Hudson, and L. Takaki. 1996. pharyngitis in a California sea otter (Enhydra Initiation of a sea otter training program. lutris). Proceedings 20mIAAAM Conference, Marine Mammal: Public Display and San Antonio, Texas. Pages 90-92. Research 2(1):43-49. Kenyon, K.W. 1969. The seaotter in the eastern Riedman, M.L., and J.A. Estes. 1990. The sea Pacific Ocean. North American Fauna, otter (Enhydra lutris): behavior, ecology, Number 68. 352 pp. and natural history. U.S. Department of Kenyon, K.W., C.E. Yunker, and I.M. Newell. Interior, Fish and Wildlife Service. 1965. Nasal mites (Halarachnidae) in the Biological Report 90(14). 126 pp. sea otter. Journal of Parasitology 51(6):960. SoulC, M.E. 1980. Thresholds for survival: Kirkpatrick, C.M., D.E. Stulken, and R.D. Jones, maintaining fitness and evolutionary Jr. 1955. Notes on captive sea otters. Journal of potential. Pages 15 1-169 in M.E. Soul6 and Arctic Institute of North America 8(1):46-59. B.A. Wilcox, editors. Conservation biology: Lacy, R.C. Vortex: a computer simulation model an ecological-evolutionary perspective. for population viability analysis. Wildlife Sinaur, Sunderland, Massachusetts. 395 pp. Research. (in press). Stetzer, E., T. D. Williams, and J. W. Lacey, R.C. and T. Kreeger. 1992. Vortex users Nightingale. 1981. Cholangiocellular manual: a stochastic simulation of the adenocarcinoma, leiomyoma, and extinction process. Chicago Zoological pheochromocytoma in a sea otter. Journal of Society, Brookfield, Illinois. 57 pp. the American Veterinary Medical Mattison, J.A., Jr. and R.C. Hubbard. 1969. Association 179: 1283. Autopsy findings on thirteen sea otters U.S. Fish and Wildlife Service. 1996. Southern (Enhydra lutris nereis) with correlations with sea otter recovery plan, 1996 draft. Ventura, captive animal feeding and behavior. California. 41 pp. Proceedings 6th Annual Conference of Vincenzi, F. 1962. The sea otter (Enhydra Biological Sonar and Diving Mammals, lutris) at Woodland Park Zoo. International Stanford Research Institute. Palo Alto, Zoo Yearbook 3:27-29. California. Pages 99-101. Whitt, A.P. 1971. The behavior of the sea otter Nakajima, M., A. Furuta, Y. Fujimaki, and J. in captivity. M.S. thesis, Pacific Lutheran Jean Brennan is Research Scientist with the Yamada. 1988. Breeding of the northern sea University, Tacoma, Washington. 170 pp. Monterey Bay Aquarium, 886 Cannery Row, otter, Enhydra lutris lutris, at Izu Mito Sea Wildt, D.E., U.S. Seal, and W.F. Rall. 1991. Monterey, California 93940. John Houck is Paradise. Japanese Association of Zoological Genetic resource banks and rep~oductive Assistant Director of Point Defiance Zoo and Gardens and Aquariums 39(2). technology for wild species conservation: Aquarium, Tacoma, Washington.

Vol. 13 No. 12 1996 Endangered Species UPDATE 67 A Complex Chromosome Rearrangement in the Karyotype of a Wild-Caught Male Sea Otter Deborah A. Duffield, Jan Chamberlin-Lea, and James E. Antrim California sea otters have been The severity and array of the Materials and methods maintained at Sea World, San Diego, abnormalities were, to us, highly Karyotypes were established from California since 1972. The sea otters suggestive of the types of birth blood and fibroblast cultures in the studied here had been integrated into malformations seen in the segregation male, and from blood cultures in the a sea otter breeding program in 1973 of chromosome anomalies in humans females. At the time of this study, no (Antrim and Cornell 1980). The early (Yunis 1977; Smith and Jones 1982). pups were available for examination. pupping history of this breeding Chromosome studies were, therefore, Blood was drawn by femoral colony, when it consisted of the undertaken on the male and three of venipuncture. Tissue and blood original male and eight females, was the females in the breeding colony to samples were refrigerated and shipped characterized by a pattern of stillbirths, investigate the possibility that there by one-day air to Portland State anomalous offspring and spontaneous was a chromosomal abnormality University for culturing. Blood abortions. The congenital anomalies segregating in this breeding colony. samples were cultured in RPMI- 1640 expressed included a heart defect, the We report here the results of media (Gibco), supplemented with absence of the digestive tract from chromosome studies undertaken on a 25% fetal calf serum, antibiotics and mouth to intestines with other male and 3 female California sea otters phytohemagglutinin (Duffield and instances of parts of the digestive tract in the Sea World sea otter breeding Chamberlin-Lea 1990). These missing (e.g., liver, pancreas), colony. We also discuss possible cultures were grow for 4 days, incomplete diaphragm and the implications of these findings to synchronized for one to two hours presence of facial anomalies, such as conservation efforts. with colcemid, followed by a second severe cleft palate and absence of eyes. 6- 10 minute colcemid synchronization 21 hours later. The cells were harvested, exposed to 0.075M KCL hypotonic, and fixed. Subsequent to the initial blood sample, the male died of septic endotoxemia and corneal fibroblasts were cultured. The fibroblast culture was grown in Hams F- 10 (Gibco), supplemented with 15% fetal calf serum, antibiotics and a fungicide, as per Duffield et al. (199 1). A variety of staining techniques were used to construct karyotypes. These included standard Giemsa staining, G-banding, C-banding (Hack and Lawce 1980), and a fluorescent R-banding technique using chromomycin A3 and distamycin A (Sahar and Latt 1978; Schweizer 1980; Duffield and Chamberlin-Lea 1990; Duffield et al. 1991).

Results Chromosome irregularities were seen in the male California sea otter karyotype when compared with the three females. The chromosomal differences in the male were Figure 1. An R-banded karyotype of a female sea otter (2N = 38). Chromosomes are consistently present in all of his cells, grouped A through D and numbered based on size and centromere position. The X both leucocyte and fibroblast, and chromosomes are indicated. were not seen in any of the cells of the

68 Endangered Species UPDATE Vo1. 13 No. 12 1996 females examined. A representative female R-banded karyotype is shown in Figure 1; the male is presented in Figure 2. The three pairs of chromosomes exhibiting a consistent irregularity in the male (b5, c 10 and c 13) are marked. The differences between the chromosome pairs in the male and in the three females is illustrated in more detail in Figure 3. The rearranged b5 homologue in the male is missing a faint-staining or 'dull' area in the short arm. The c 10 rearrangment represents a possible inversion of the short arm of the chromosome (see Figure 4) and there is an apparent difference in the short arm and centromere region of one of the chromosomes of pair c13, as compared to the other homologue and to the chromosomes of the females.

Discussion The precise nature of the chromosomal changes in the male California sea otter are not easy to Figure 2. An R-banded karyotype of the male sea otter in question in this study (2N = resolve without chromosomal 38). The chromosome pairs exhibitingconsistent irregularityare indicatedby arrows. evaluation of the abnormal offspring. Many species of marine mammals have variable fluorescent R-band regions, the normal vs. abnormal interpretation Several of these exhibited congenital referred to as heteromorphisms of this particular chromosome. The anomalies. The anomalies were not (Duffield and Chamberlin-Lea 1990; types of changes in the other two confined to particular matings, but Duffield et al. 1991). These variable chromosome pairs have not been seen appeared in offspring of several of the regions can differ between individuals as normal chromosome variants in females. Of the live births, five pups within populations and are considered other marine mammal species studied lived only 1-2 days. One was to be normal variants in the with R-banding, and from the congenitally abnormal, the others were chromosomes . The apparent anomalies seen in the pups sired by either under normal birth weight (as inversion in chromosome c10 could, this male, it would seem likely that compared to values of 1.4 - 2.3 kg indeed, be an example of normal R- there was, indeed, a complex reported for successful births in wild band differences in the centromeric chromosomal rearrangement in the sea otters: Kenyon 1969; Estes 1980) and short arm telomeric region of this karyotype of the breeding male. Since and congenitally weak, or appeared chromosome. However, this variant this wild-caught male was malnourished and died of maternal was not seen in any of the females, nor phenotypically normal, it was neglect. There were three pups of in another male karyotyped subsequent presumed that he was a balanced good birth weight, who lived for a to this study (this male was carrier for this rearrangement. longer period of time. One female chromosomally similar to the three Balanced complex de novo pup lived for approximately two weeks females and did not exhibit any chromosome rearrangements have and died of a respiratory infection. karyotypic irregularities). It was been reported in humans (e.g., Another female pup died after 21 days judged to be an inversion because of Magenis et al. 1981). of malnutrition and maternal neglect. the way it visually matched an The pupping history in the sea One male pup lived for four months, "inversion" produced by physically otter colony for the period involved dying of congestive heart failure inverting the short arm of chromosome the breeding of this male and the eight resulting from an apparent congenital c10 in the females (see Figure 4). females. Eighteen pups, all sired by heart defect. Interbirth intervals However, only a small number of the one male present in the breeding ranged from 7 months 25 days to over California sea otters have been colony, were born from 1975 to 1982. 31 months, with a median interbirth examined and future karyotyping of There was one set of twins. Eleven interval of 11 months. Therefore, in more animals would help to resolve pups were stillbirths or abortuses. this breeding colony where there was

Vol. 13 No. 12 1996 Endangered Species UPDATE 69 defects (Vogel and Motulsky 1979; Gadow et al. 1991), certainly characterize the pupping history in this colony.

Implications for conservation efforts Congenital malfor- mations can also be caused by a number of environmental factors. The possibility that the birth anomalies were caused by a teratogenic agent cannot totally be ruled out in the absence Figure 3. The abnormal homologues in the breeding male compared with the homologuesof those same of verification of karvo- chromosome pairs in the three females examined in this study. The areas lndicate regions of typicabnomalitiesin;he irregularity. anomalous offspring.- - However, it can be argued continual access to a male, there is the some rearrangement involving small that given the range of congenital de- possibility of additional undetected chromosome segments. fects, as well as the presence of appar- pregnancies and spontaneous Interpretation of the observed ently phenotypically normal offspring abortions during the apparently longer congenital anomalies as directly in this colony, one would not expect interbirth intervals. resulting from genetic missegration the problem to be related to a single Given the normal chromosome of a complex chromosome teratogenic agent, nor to any single, pairs seen in the karyotypes of the rearrangement in the male is consistent factor in their environment. females examined, the existence of complicated by two factors. At the A study of the water environment of the chromosomal irregularities in the time of this study, the offspring could this sea otter colony was undertaken, male karyotype suggested that he was not be karyotypically examined to subsequently to the chromosome a major contributor to the reproduc- associate specific chromosomal study, to see whether the water qual- tive problems in the breeding colony. duplication or deficiencies with the ity treatment or filtering of water in Numerous examples of chromosomal presence of anomalies. Furthermore, this particular system produced a ter- rearrangements producing multiple there is evidence both from captive atogenic-like effect on in vitro cells congenital anomalies are described in breeding of sea otters (Antrim and (Nicholas and Duffield, unpublished humans (Yunis 1977; Smith and Jones Cornell 1980) and from the wild observation). Cells were grown in 1982). With the increased chromo- (Kenyon 1969), that first-time births water from a variety of sources and somal resolution made possible by have a lower success rate and are often were scored for chromosome damage; chromosome banding techniques, characterized by stillbirths or failure such as, breaks, rearrangements and many cases of fetal and newborn ab- of the pups to thrive. These effects sister chromatid exchanges. The normalities and malformations, and would have also contributed to the highly treated water of the sea otter of increased rate of spontaneous abor- pupping history in this breeding filtration system, compared with other tion and stillbirth, have been associ- colony. To this latter point, however, sources, which included purified wa- ated with families carrying balanced the consistent pattern of congenital ter, local bay water and local drinking chromosome rearrangements, includ- anomalies, stillbirths and spontaneous water, was ranked as having no added ing both simple and complex translo- abortions throughout the breeding effect on chromosomal change in cul- cations and inversions (Budberg et al. history of a number of the females, ture when compared to the purified 1982; Buchinger et al. 198 1; Ander- argues against this being the only water control. It is interesting, as an son et al. 1981; Cohen et al. 1983; explanation for the breeding problems. aside, that the local drinking water Ostovics et al. 1982; Palmer et al. The most common signs of autosomal had a statistically significant effect on 1987; Gadow et al. 1991). The occur- chromosome aberrations, which chromosome breakage and rearrange- rence of late pregnancy abortions, fail- include increased spontaneous and ment in the cultures. ure to thrive, maternal neglect and the stillbirth rates, and in live offspring, Potentially, there is also the range of abnormalities seen in the low birth weight, failure to thrive, possibility that the apparent offspring in this breeding colony mental retardation, head and facial "irregularities" in the chromosome would be consistent with a chromo- anomalies and heart and abdominal pairs of the male resulted from a cross

70 Endangered Species UPDATE Vo1. 13 No. 12 1996 Figure 4. A proposed inversion explaining the rearrangement in c10 in the male ssa otter. The inversion was modeled by inverting the equivalent part of the short arm of one of the clO chromosomes in a female karyotype (A - 6) and comparing it vlsuaily to the "rearranged" chromosome in the male (C).

between parents from stocks of wild Scribner et al., in press). This would Vogt 1983; Bongso andBasrur 1976), sea otters which were chromosomally imply that deleterious effects, such sheep (Bruere 1969), pigs (Akesson differentiated. For example, there has as, increased mortality in young ani- and Henricson 1972; Henricson and been continuing controversy over the mals and reduced fertility expected as Backstrom 1964) and horses (Hughes discreteness of Alaskan and a result of loss of genetic variability, and Trommershausen-Smith 1977). Californian sea otter populations would not be an anticipated conse- These have been associated with (Kenyon 1969; Lidicker and quence of the near extinction of the physical anomalies, fetal death and McCollum 1981; Wilson et al. 1991; California population (Ralls et al. reproductive inefficiency. Balanced Cronin et al. 1996). The male in 1983; Cronin et al. 1996). On the translocations have been reported for question came from Monterey Bay, other hand, from a genetic drift argu- wild-caught cetaceans (Duffield 1977; California. However, with the ment, if one of the subsequentfounders Worthen 1981). The presence of a occasional introduction of Alaskan sea of the current population, i.e. one of camer of a chromosomal rearrange- otters along the Oregon and the survivors, was carrying a chromo- ment in a wild sea otter is, therefore, Washington coasts (see Jameson et al. some rearrangement, the frequency of not in itself, surprising. However, in 1982), there is a possibility, although that rearrangement in the recovered a population which has suffered the thought to be remote, that some of population could be fairly high based degree of genetic bottlenecking and these have been integrated into the on chance contributions of individual reduction in numbers seen with the California population. If these two founders. In time, selection would be California sea otter, it might be useful populations were chromosomally expected to lower the frequency of the to further evaluate the frequency of distinct, a cross between them would chromosome rearrangement, but in the chromosomal rearrangements in the certainly give rise to an individual interim, because of its effect on re- current population. exhibiting irregular pairing of duced fertility (Tupler et al. 1994) as In terms of the impact on captive chromosomes. An R-band karyotype well as on lowered pup production breeding programs, the finding of a has not yet been done for the Alaskan through spontaneous abortion and fail- phenotypically normal, but sea otter to test this possibility. Either ure to thrive, it might have a signifi- karyotypically abnormal wild-caught source, structural rearrangement or cant impact on the observed rate of male in the Sea World breeding population difference, could have recovery of the population. This would colony, emphasizes the importance of resulted in the production of be true, as well, if the source of chro- screening potential breeding animals anomalous offspring by the carrier mosome irregularity were the conse- for chromosomal rearrangements animal. quence of breeding between individu- which could lead to costly risk of Ralls et al. (1983) predicted that als of chromosomally differentiated abnormal births and compromised despite the population bottleneck in subspecies subsequent to sea otter breeding success in captive breeding the California sea otter population translocation efforts. programs. This is especially important caused by fur hunting in the 18th and The frequency with which bal- in breeding colonies built around a 19th centuries, 77% of the original anced chromosome rearrangements single male or a single breeding pair genetic diversity would be expected occur in the wild is not known for of animals. to be retained and that the bottleneck most species. In man, the frequency would, therefore, not have had much of balanced autosomal rearrangements Acknowledgments impact on loss of genetic variation. estimated from prenatal cytogenetic Special thanks to the animal care staff Genetic variation in both allozymes studies ranges from 0.224% (Hook et at Sea World for their collection of and mtDNA has been subsequently al. 1983) to 0.4% (Van Dyke et al. reproductive data from the sea otter demonstrated in various sea otter 1983). Chromosome abnormalities breeding colony, and to Ann Nicolas populations (see Cronin et al. 1996; are reported for cattle (Swartz and who helped to design and conduct the

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The frequency and Zoo Yearbook 20:76-80. Jameson, R., K.W. Kenyon, A.M. Johnson, mutation rate of balanced autosomal Bongso, A. and P.K. Basrur. 1976. and H.M. Wright. 1982. The history and rearrangements in man estimated from Chromosome anomalies in Canadian status of translocated sea otter populations prenatal genetic studies for advanced Guernsey bulls. Cornell Vet. 66:476-489. in North American Wildlife Society Bulletin maternal age. American Journal of Human Bruere, A.N. 1969. Male sterility and an 10: 100-107. Genetics 35 (2):301-307. autosomal translocation in Romney sheep. Kenyon, K.W. 1969. The sea otter in the eastern Vogel, F. and A.G. Motulsky. 1979. Human Cytog. 8:209-218. Pacific ocean. North American Fauna, genetics, problems and approaches. Springer- Buchinger, G., A. Wettstein, and H. Metze. Number 68. 352 pp. Verlag, New York, New York. 700 pp. 1981. Familial chromosome translocation Lidicker, W.Z. and F.C. McCollum. 1981. Wilson, D.E., M.A. Bogan, R.L. Brownell, Jr., t(3: 18)(p21;p11). Journal of Med. Genetics Genetic variation in the sea otter, Enhydra A.M. Burdin, and M.K. Maminov. 1991. 18:119-123. lutris. Fourth Biennial Conference on Geographic variation in sea otters, Enhydra Budberg, A., L. Iselius, L. Lindgren, and K.M. Biology of Marine Mammals, San Francisco, lutris. Journal of Mammology 72 (1):22-36. Lundmark. 1982. Duplication of part of the California. (Abstract). Worthen, G.L. 1981. Preliminary analysis of long arm of chromosome 8 due to a familial Magenis, E., M.G. Brown, J. Chamberlin, T. the potential for stock assessment of Pacific 8: 13 translocation. Hereditas 96: 105-108. Donlon, D. Hepburn, N. Lamvik, E. Lovrien, ocean Delphinids by G and C chromosome Cohen, M.M., J. Charrow, N. Balken, and C. and M. Yoshitomi. 1981. Resolution of banding. National Marine Fisheries Service Harris. 1983. Partial trisomy 14 (q23-qter) breakpoints in a complex rearrangement by Administrative Report LJ-8 1-02C. 99 pp. via segregation of a 14lX translocation. use of multiple staining techniques: Yunis, J.J. 1977. New chromosomal syndromes. American Journal of Human Genetics. confirmation of suspected 12p12.3 intraband Academy Press: New York, New York. 404 pp. 35(4):635-645. by deletion dosage effect of LDH-B. Cronin, M.A., J. Bodkin,B. Ballachey, J. Estes, American Journal of Human Genetics 9:95- and J.C. Patton. 1996. Mitochondrial-DNA 4 n- 1UJ. variation among subspecies and populations Ostovics, M.K., S.P. Toth, and J.A. Wessely. of sea otters (Enhydra lutris). Journal of 1982. Cytogenetic investigations in 419 Mammalogy 77 (2):546-557. couples with recurrent fetal wastage. Ann. Duffield, D.A. 1977. Phylokaryotypuc de Genetique 25 (4):232-236. evaluation of the cetacea. Ph.D. dissertation. Palmer, C.G., J.H. Miles. P.N. Howard-Peebles, University of California, Los Angeles, R.E. Magenis, S. Patil, and J.M. Friedman. California. 154 pp. 1987. Fetal karyotype following Duffield, D.A. and J. Chamberlin-Lea. 1990. ascertainment of fetal anomalies by Use of chromosome heteromorphisms and ultrasound. Prenatal Diagnosis 731-555. hemoglobins in studies of bottlenose dolphin Ralls, K., J. Ballou, and R.L. Brownell, Jr. populations and paternities. Pages 609-622 1983. Genetic diversity in California sea in S. Leatherwood and R.R. Reeves, editors. otters: theoretical considerations and The Bottlenose Dolphin. Academic Press, management implications. Biological San Diego, California. Conservation 25:209-232. Duffield, D.A., J. Chamherlin-Lea, J.C. Sahar, E. and A. A. Latt. 1978. Enhancement Sweeney, D.K. Odell, E.D. Asper, and W.G. of the handing patterns in human metaphase Gilmartin. 1991. Use of corneal cell culture chromosomes by energy transfer. for R-band chromosome studies on stranded Proceedings of National Academy of Science cetaceans. Pages 91-100 in J.E. Reynolds U.S.A. 75 (11):5650-5654. and D.K. Odell, editors. NOAA Technical Schweizer, D. 1980. Simultaneous fluorescent Report NMFS 98. staining of R-bands and specific Estes, J.A. 1980. Enhydra lutris. In: heterochromatic regions (DA-DAPI bands) Mammalian Species. American Society of in human chromosomes. Cytog. and Cell Mammalogy. No. 133:l-8. Genetics 27: 190-193. Gadow, E.C., S. Lippold, L. Otano, E. Serafin, Scribner, K.T., J. Bodkin, B. Ballachey, S.R. R. Scarpati, and T. Matayoshi. 1991. Fain, M.A. Cronin, and M. Sanchez. In press. Deborah Duffleld and Jan Chamberlin-Lea can Chromosome rearrangements among couples Population genetic studies of the sea otter be contacted at the Department of Biology, with pregnancy losses and other adverse (Enhydra lutris): a review and interpretation Portland State University,Portland, Oregon reproductive outcomes. American Journal of available data. U.S. Department of 97201. James Antrim works with Sea World of of Med. Genetics 41:279-28 1. Commerce, National Oceanic and California, San Diego, California 92109.

72 Endangered Species UPDATE Vol. 13 No. 12 1996 The Law Governing Sea Otter Conservation Donald C. Baur, Allison M. Meade, and Lisa M. Rotterman

The sea otter has the distinction of and others, have only rarely benefited mals are, or may be, in danger of extinc- being one of the first animals protected from our interest; they have been shot, tion or depletion as a result of man's under federal law. In 191 1, the United blown up, clubbed to death, run down activities" (16 U.S.C. !$ 1361(1)), Con- States joined Great Britain, Japan, and by boats, poisoned, and exposed to a gress set forth in the MMPA a mandate Russia to execute the Convention for multitude of other indignities, all in the that marine mammals "should be pro- the Preservation and Protection of Fur interest of profit or recreation, with tected and encouraged to develop to the Seals, a treaty prohibiting pelagic seal- little or no consideration of the poten- greatest extent feasible commensurate ing and the taking of sea otters on the tial impact of these activities on the with sound policies of resource man- high seas. The United States imple- animalpopulationsinvolved (H.R. Rep. agement and that the primary objective mented this Convention, and imposed a No. 707, 92d Cong., 1st Sess. 11-12, of their management should be to main- prohibition on high seas sea otter tak- 1971). tain the health and stability of the ma- ing, by the Fur Seal Act of 1912 rine ecosystem"(Id. !$ 136l(6)). Federal (Chap. 373,37 Stat. 499,1912). As a result of the resulting legal agencies thus were directed that "such At the time it was imposed, this protection, the status of the sea otter has species and population stocks should protection was of little value for sea significantly improved. Sea otters now not be permitted to diminish beyond the otters. The once prolific species, which occupy a number of areas within their point at which they cease to be a signifi- had occupied arange from Japan, across historic range: Alaska, British Colum- cant functioning element in the ecosys- the Pacific rim, down the Pacific coast bia, Washington, and California. The tem of which they are a part, and, of North America, and into Mexico was population of animals in California is consistent with this major objective, on the brink of extinction. Its numbers currently designated as a separate sub- they should not be permitted to dirnin- ravaged by the fur trade of the 18th and species (see Anderson et al., this issue). ish below their optimum sustainable 19th centuries, the sea otter survived, Each of these populations is subject to population" (Id. !$ 136l(2)). not because of the 1911 treaty or its varying degrees of legal protection. As Pursuant to the MMPA, jurisdic- implementing U.S. law, but because the a result, separate policy and manage- tion over the sea otter is vested in the animals were simply too scarce to jus- ment issues arise in connection with Secretary of the Interior and adminis- tify the cost of searching them out and each. tered by the U.S. Fish and Wildlife killing them for their skins. In addition, The two major federal laws gov- Service (FWS). Oversight is provided the prohibition on take applied only on erning sea otters are the Endangered by the Marine Mammal Commission the high seas (beyond three miles), a Species Act (ESA) and the Marine Mam- and the Committee of Scientific Advi- delineation that was insufficient to pro- mal Protection Act (MMPA). Marine sors on Marine Mammals (Id. !$ 1402). tect a mostly near-shore species such as mammal populations listed either as The MMPA established four inno- the sea otter. endangered or threatened under ESA vative concepts of wildlife protection This pattern of legal protection- are by default categorized as depleted and management that are relevant to the after-it-was-almost-too-late is not un- under MMPA. Removal from lists de- sea otter: (1) preemption of state con- common for many marine mammals fined by ESA also automatically re- trol over marine mammals; (2) imposi- and other protected species. Until the moves the depleted designation as tion of a moratorium on the taking and early 1970s and the enactment of the defined by MMPA. An approved peti- importation of marine mammals; (3) es- Marine Mammal Protection Act in 1972 tion is required for populations not listed tablishment of the species and popula- and the Endangered SpeciesAct amend- under ESA to be listed as depleted un- tion stock recovery goal of reaching and ments of 1973, sea otters and other der MMPA. The provisions of the ESA maintaining optimum sustainablepopu- wildlife species at risk from human ac- are discussed elsewhere in this issue lation (OSP) levels; and (4) recognition tivities had little or no legal protection. (see Clark, this issue), and this paper of marine mammals as vital compo- As Congress observed in 1971 when it will summarize the Marine Mammal nents of the overall marine ecosystem took up the MMPA for consideration: Protection Act and discuss the resulting and establishment of ecosystem health conservation issues associated with sea and stability as the primary goal of Recent history indicates that man's otters in California. marine mammal management. impact upon marine mammals has ranged from what might be termed ma- The Marine Mammal Protection State control of marine mammals lign neglect to virtual genocide. These Act Having removed states from direct animals, including whales, porpoises, Having found that "certain species control over the taking of marine marn- seals, sea otters, polar bears, manatees and population stocks of marine mam- mals, Congress also set forth in the

Vo1.13 No. 12 1996 Endangered Species UPDATE 73 MMPA mechanisms whereby states to harass, hunt, capture, or kill could regain some or all of that authority. any marine mammal" (Id. In 1974, California invoked this 5 1362(13);5OC.F.R. 8 18.3). procedure and filed a request for a waiver The prohibition on taking, un- of the moratorium and a transfer of less subject to an MMPA ex- management for sea otters. Pursuant to ception, is absolute, and that request, the state sought to establish takings that are incidental to a management regime that would have otherwise lawful activities are restricted sea otters to their then current prohibited to the same degree range along the central California coast. as intentional takes. By mid-1976, however, the California The Act, as amended over Department of Fish and Game (CDFG) the years, sets forth several recognized that many of the goals it exceptions to the moratorium. sought to achieve pursuant to a manage- These exceptions are for: (1) ment transfer, including testing of the scientific research; (2) public effectiveness of translocation as a display; (3) photography for method of regulating sea otter distri- educational or commercialpur- bution, could be accomplished under poses; (4) enhancing species an MMPA scientific research permit. survival or recovery; (5) inci- Consequently, the waiver request was dental take in commercial fish- Photograph by Jeff Foott withdrawn and a research permit ap- ing operations; and (6) plication filed. incidental take of small numbers of ma- to commercial fishing. During the early Describedas "anexperimental man- rine mammals in non-commercial fish- 1980s, it was discovered that southern agement plan," the research permit was ing activities. sea otters were dying in high numbers in requested in order to "provide an ad- In addition to these exceptions, the California set net fisheries. This inci- equate number of sea otters for mainte- moratorium does not apply to dental take was causing the population, nance of a healthy self-sustaining nonwasteful takes by Alaskan Natives which had only recently begun to re- population" and to "restrict the distribu- for subsistence or handicraft purposes cover, to once again decline. Under the tion of the sea otter to protect the State's (Id. 8 1371(b)). This exception is lim- MMPA as it existed at that time, all remaining recreational and commercial ited to any Indian, Aleut, or Eskimo incidental take of depleted marine mam- shellfish fisheries and to enable pos- who resides in Alaska and dwells on the mals (including the southern sea otter) sible development of marine aquacul- coast of the North Pacific Ocean or the was prohibited and could not be autho- ture in coastal waters." The FWS issued Arctic Ocean. In the 1994 Arnend- rized. Because of this prohibition, the a two-year permit on August 26, 1977 ments, Congress gave greater recogni- state of California imposed a series of (42 Federal Register 44,314, Sept. 2, tion to the need to promote acooperative fishery closures throughout the seaotter 1977). As issued, the permit authorized approach with Alaska Natives by au- range (discussed below). These clo- CDFG to capture, tag, weigh, measure, thorizing the federal agencies to enter sures were essential to eliminating this and blood sample up to 100 animals into "co-management agreements"with take and putting the southern sea otter from the northern end of the sea otter Alaska Native organizationsfor the pur- back on the track of recovery. range. It also authorized the transloca- pose of undertaking research, manage- tion of up to 40 sea otters from southern ment and conservation efforts on a joint Optimum sustainable population to the northern end of the range. As basis (Id. 8 1388). Linked to the application of the federal efforts to achieve zonal man- Addressing Native take outside of moratorium are the concepts of OSP agement intensified, the state declined Alaska under the 1994 MMPA amend- and depletion. The MMPA defines OSP to further pursue the research effort, and ments, Congress clarified that nothing to mean: a return of management was not pur- in those amendments was intended to sued again. impinge on pre-existing Indian treaty [Wlith respect to any population rights (Pub. Law No. 103-238,s 14). In stock, the number of animals which will Moratorium on taking those amendments, however, Congress result in the maximwn productivity of In conjunction with the preemption did not extend this nonabrogation clause the population or the species, keeping of state authority, Congress imposed a to the pre-existing provisions of the in mind the carrying capacity of the moratorium on the taking and importa- MMPA. Thus, the take prohibition habitat and the health of the ecosystem tion of all marine mammals (16 U.S.C. would override any pre-existing treaty of which they form a constituent ele- 8 1371 (a)(l)). The expansive scope of rights that might exist to hunt sea otters. ment (Id, 8 1362(8)). this moratorium is established by the An especially important aspect of definition of "take," which means "to the MMPA protections applying to sea Any species or population stock harass, hunt, capture, or kill, or attempt otters is the take prohibition as it applies that has been listed as endangered or

74 Endangered Species UPDATE Vol. 13 No. 12 1996 threatenedunder the ESA or determined otters in Alaska asserts that the popula- new provisions that allowed for inci- to be below its OSP level is defined as tion is believed to be within its OSP dental take of depleted species (16 "depleted" (Id. $ 1362(1)). If a species range, but this conclusion is based on U.S.C. fj 1387(a)(4)). Thus, of all the or stock is below OSP and thus, by the highly questionable assumption that species subject to the MMPA, only the definition depleted, it is effectively pre- there is a single population stock in southern sea otter still has the benefit of cluded from being made subject to a Alaska (U.S. Fish and Wildlife Service the strong legal protections enacted by waiver of the moratorium, cannot be 1995). No OSP finding has been made Congress in 1972prohibiting incidental taken under a state management pro- for the southern sea otter. Although the take of depleted marine mammals. gram, and cannot be taken under permit depleted status of the southern sea otter except for scientific research, species is formally derived from its ESA classi- Marine ecosystem protection enhancement, or photographic purposes. fication (50 C.F.R. $ 17.1l(h)), there is In enacting the MMPA, Congress Limitations also apply to incidental take no question that the southern sea otter made maintenance of the health and of depleted species, although after the also is well below its MNPL. Determi- stability of the marine ecosystem the 1994 MMPA amendments such take nation of the MNPL for the southern sea primaryobjective(l6U.S.C. $ 1361(6)). under most commercial fishing is no otter is likely to be particularly difficult OSP is to be achieved when consistent longer prohibited and exemptions also based upon present knowledge due to with this goal. Because sea otters are exist for some non-fisheries' incidental the uncertainty of the pre-exploitation often recognized as a "keystone spe- take. population size, the fact that the sea cies" which indicates ecosystem health, For purposes of implementing the otter is recovering from harvests that it is clear that promoting population and OSP concept, in 1976 NMFS promul- took place before reliable records were range expansion of this species advances gated the following "interpretative"defi- kept, the lack of a clear understanding this underlying goal of the MMPA. nition: of the relationship between sea otters Without refemng specifically to and the near-shore marine community, habitat protection or other measures, "Optimumsustainable population" and the fact that at least portions of the section 112 authorizes the Secretary to is apopulation size whichfalls within a formerly occupied range are no longer "prescribe such regulations as are nec- range from the population of a given suitable as sea otter habitat. essary and appropriate to carry out the species or stock which is the largest In 1988 and 1994, Congress purposes of the MMPA" (Id, $ 1382(a)). supportable within the ecosystem to the amended the MMPA to provide more This authority can be used to promul- population level that results in maxi- flexibility in authorizing incidental take gate regulations to protect habitat areas. mum net productivity. Maximum net of marine mammals in commercialfish- In the legislative history of the 1994 productivity is the greatest annual in- eries. Congress passed this amendment Amendments, Congress made it clear crement in population numbers or bio- in reaction to the decision in Kokechik that section 112 includes such author- mass resulting from additions to the Fishermen's Association v. Secretary of ity. As stated by the House Merchant population due to reproduction ador Commerce (839 F.2d 795, 802, D.C. Marine and Fisheries Committee in its growth less losses due to natural mor- Cir. 1988), which held that no permit legislative history for amendments to tality (50 C.F.R. $ 216.3). could be issued under the MMPA to section 2(2), by adding the phrase "es- take a depleted species and that if a sential habitats," "[tlhe Committee be- Because the maximum net produc- proposed fishery would take depleted lieves that the Secretary currently has tivity level (MNPL) is the lower end of as well as nondepleted species, the fish- the authority to protect marine mam- the OSP range, it has been the focal ery itself could not be authorized. Fear- mals and their habitats under the gen- point of conservation efforts under the ing that this rule would shut down many eral rulemaking authority of section 112 MMPA. MNPL is defined as "thegreat- fisheries in the United States, Congress of the MMPA" (H.R. Rep. No. 439, est net annual increment in population established a new regime for authoriz- 103d Cong., 2d Sess. 29 (1994)). The numbers or biomass resulting from ad- ing incidental take that allowed depleted Committee expressly noted, as an ex- ditions to the population due to repro- species to be taken. ample, that this authority would apply duction and/or growth less losses due to Congress recognized, however, that "to protect polar bear denning, feeding, naturalmortality"(16U.S.C. $ 1362(9)). the southern sea otter was a special case. and migration routes . . . ."(Id.). Thus, As applied in numerous rulemaking pro- Because the sea otter is especially vul- this authority also could be used to ceedings, MNPL has been generally nerable to incidental take, in recogni- protect sea otter habitat by, for ex- accepted to mean a population size that tion of the link between the MMPA ample, prohibiting or restricting hu- represents 60 percent of the species' or absolute ban on taking depleted species man activities that pose threats to sea stock's carrying capacity (e.g., 42 Fed- and the state's closures, and in an effort otters (Baur 1996). eral Register 64,548 (1977); 45 Federal to maintain the status quo under the sea The second important federal law Register 72,178 (1980)). otter translocation law (discussed be- governing sea otter conservation is the To date, there has been no formal low), which established two stringent ESA. The provisions of the ESA are determination of OSP for sea otters. "no take" zones for sea otters, Congress discussed in detail elsewhere in this The FWS 1995 stock assessment for sea exempted southern sea otters from these issue (see Clark, this issue). By way of

Endangered Species UPDATE 75 summary, several aspects of the ESA existing population and any new colo- however, hampered by the opposition are of special significance to the sea nies; and of commercial interests and questions otter. Section 4 defines the criteria and (5) integrate the recovery plan into about whether the FWS could relocate procedures for listing species under the development and management plans of seaottersin the face of MMPA "no-take" ESA (16 U.S.C. $1373). Distinctpopu- local coastal governments (uat 40). prohibitions. lations are subject to listing (61 Federal The establishment of one or more The matter was settled in 1986 with Register 4722, 1996). Under section 4, colonies has been identified as the most enactment of Pub. Law No. 99-625,100 the southern sea otter is designated as a important task to be accomplished for Stat. 3500 (1986), in which Congress threatened species. The small popula- bringing about recovery of the subspe- adopted the zonal management concept tion in Washington (about 350 animals) cies (Id. at 34). and specifically authorized the FWS to might also qualify for listing. The 1982 southern sea otter recov- carry out one or more relocations out- Once listed, a species is subject to ery plan remains in effect. It is currently side the southern sea otters' mainland the ESA's take prohibition (16 U.S.C. $ being revised through a process which range (see Benz, Attempts to Reintro- 1358 (a)(l); 50 C.F.R. $ 17.21). This has now been underway for several years duce, this issue). Subsequently, the prohibition is broader than that under (see Benz, Recovery Plan, this issue). FWS decided on San Nicolas Island, the MMPA because it also prohibits This revision process began in 1989, in and established a translocation zone "harm" to a species, which includes part as a result of the Exxon Valdez oil around San Nicolas, and, outside of habitat degradation (50 C.F.R. 5 17.3; spill in Alaska. The size of this spill and that, a management zone including all Babbitt v. Sweet Home Chqter of Com- its impact on sea otters demonstrated waters south of Point Conception (see munities for a Great Oreyon, 115 S. Ct. that the entire southern seaotter popula- Wendell, this issue). Sea otters found in 2407, 1995). The ESA also prohibits tion would be at risk from such an event. either zone are presumed by the law to the federal government from taking any This information called into question be members of the translocated popula- action that is likely to jeopardize the some of the key assumptions in the tion. Inside the translocation zone, sea continued existence of the species in the 1982 Recovery Plan. otters are accorded full ESA protec- wild (Id 5 1536 (a)(2)). The goal of the Upon publication of this article, the tions, with one partial exception: sec- ESA is to achieve recovery of listed revised recovery plan was undergoing tion 7 federal agency consultations are species (Icl. $5 1531, 1532 (3)). TO its second public review period. The required only for non-defense related accomplish this goal, section 4(f) of the draft revised recovery plan focuses al- actions occurring inside the transloca- ESA requires that recovery plans be most exclusively on oil spill risk and tion zone, rather than for all federal issued by FWS for most listed species does not address other threats, includ- actions that may affect the population (Id, $ 1533 (f)). ing new threats that did not exist in (Pub. Law No. 99-625, § l(c)). In the The FWS issued its original recov- 1977. It also does not address OSP management zone, on the other hand, ery plan for the southern sea otter on under the MMPA (U.S. Fish and Wild- sea otters are accorded only the status February 2, 1982. The Recovery Plan life Service 1996). These and other of species proposed to be listed under addresses necessary actions to achieve aspects of the draft revised recovery the Act (requiring only the informal both delisting under the ESA and attain- plan have been the subject of debate and conference procedure). Incidental tak- ment of OSP under the MMPA. With controversy (see Faurot-Daniels and ing of sea otters in the management regard to prospects for species recovery Baur, this issue). zone may not be treated as violations under the ESA, the Recovery Plan states of the ESA or the MMPA (Pub. Law that "delisting should be considered The translocation law 99-625, 5 l(c)). when the southern sea otter population The 1982 recovery plan identified The FWS released 139 sea otters is stable or increasing at sustainable the establishment of anew colony of sea between 1987 and 1990. Counts be- rates in a large enough area of their otters, apart from the mainland popula- tween 1993 and 1995 have shown a original habitat that only a small pro- tion, as the most important step in en- stable population of 12 to 15 adults and portion would be decimated by any suring that a single oil spill or similar continued pupping (six pups were single natural or man-caused catastro- catastrophe could not endanger the en- known to have been born on the island phe" (U.S. Fish and Wildlife Service tire population (Uat 34). The recovery in 1995; Marine Mammal Commission 1982). For purposes of achieving this plan adopted the idea of zonal manage- 1996). According to the plan, the popu- objective, the Recovery Plan indicates ment earlier put forward by the Marine lation can be considered "established" that it is necessary to accomplish all of Mammal Commission to deal with con- when the population (1) numbers 150 the following: flicts between range expansion of the sea otters, with little or no migration to (1) minimize the risk of oil spills; sea otter and human activities, espe- management zone and (2) recruits (i.e., (2) minimize the possible effects of cially commercial and recreational fish- successfully pups) 20 sea otters a year oil spills; eries (U.S. Fish and Wildlife Service for a three to five year period or main- (3) minimize vandalism,harassment, 1982; Marine Mammal Commission tains a population close to the island's and incidental take of sea otters; 1996; see Wendell, this issue). Early carrying capacity. At present, the San (4) monitor recovery progress of the planning for a relocation effort was, Nicolas population has no legal signifi-

76 Endangered Species UPDATE Vol. 13 No. 12 1996 coastal areas inhabited by sea otters $5 8610.1-15,8618.0-8618.2,8664). California has also listed the south- ern sea otter as a "fully protected rnam- rnal" under state law, meaning that it "may not be taken or possessed at any time" except pursuant to permits issued for sci- entific research IId. at 5 4700). (Consis- tent with the translocation law, however, incidental take of sea otters south of Point Conception but outside of the San Nicolas translocation zone is not to be considered a violation of the California law (U. at 8664.2; see Wendell, this issue)). Finally, in 1990, California enacted Photograph by Jeff Foott legislation requiring that a network of cance with regard to the status of south- (Personal Watercraft Industry Associa- rescue and rehabilitationcenters be estab- ern sea otters as a whole under the ESA tion v. Devartment of Commerce, 48 lished to deal with sea birds, sea otters, and MMPA. However, if the popula- F.3d 540, 545, D.C. Cir. 1995; see and other marine mammals in the event of tion becomes established it will be taken Saunders, this issue). oil spills (California Government Code into account for future consideration of 5 8670.37.5; see Jessup et al., this issue). delisting the sea otter under the ESA or State Laws removing its designation as "depleted" In addition to the federal statutes Conservation issues under the MMPA (50 C.F.R. described above, various state laws are In California, the principal conserva- 17.84(d)). The FWS regulations also significant to the recovery and manage- tion issues arise from the effort to direct define criteria for determining the trans- ment of seaotters. Although laws directly the sea otter recovery program in a rnan- location a failure, which would require governing sea otters are preempted by the ner that will truly result in recovery of the the sea otters at San Nicolas to be cap- MMPA, a number of state laws intended species. There are several complex issues tured and returned to the range of the to protect a variety of species provide presented by this question. parent population and termination of benefits to sea otters. (1) Can sea otter recovery be de- the management zone (Id. Most significant are California re- fined simply in terms of attaining a 5 17.84(d)(8)). Even if any one of these strictionsthat have been imposed on tram- given population level, without refer- criteria are met, the FWS has discretion mel and gdl net fisheries since the early- ence to other standards, such as range to continue the translocation if reason- and mid-1980s, when the State Legisla- expansion, distribution, measures to able measures can be implemented to ture recogruzed that these net fisheries avoid oil spill, analysis of infectious address the identified problems (a were causing sigmficant incidental take disease and other threats, etc.? 5 17.84(d)(8)(v)). of sea otters as well as other marine mam- (2) Is the proposed number for mals and sea birds (California Fish & delisting (2,650 maintained over three Protected areas Game Code 8 8609). In 1982, legislation years) sufficientconsidering unresolved Sea otters and sea otter habitat also was passed prohibiting use of these nets in threats to the species and when the his- benefit as a result of protective federal certain shallow (10 to 15 fathoms deep or toric population size for this species is land and water area designation. Na- less) coastal waters @at 8664.5). Sub- 14,000 or greater? tional parks, such as the Channel Is- sequently, these fishing prohibitions were (3) Can delisting be predicated upon lands in California and Olympic in extended to cover deeper and deeper wa- merely a current assessment of the Washington, national wildlife refuges, ters, and the Director of the California threats posed in 1977, or must new such as Alaska Maritime, and marine Department of Fish and Game was autho- threats also be considered? sanctuaries, such as Monterey Bay and rized to close any area to all net-setting (4) Should zonal management be Olympic Coast, provide such protec- upon a finding that such fishing is causing abandoned? If so, how will the require- tion by prohibiting habitat modifica- an "adverse impact on any population of ments for maintenance of the transloca- tions and activities that could harm sea any species of sea bird, marine mammal, tion and management zones of the otters (Baur 1991). In the Monterey or fish" (U at $5 8664.5, 8664.8). In translocation law be addressed? Bay Sanctuary,regulations promulgated 1990, a popular referendum, the Califor- (5) Should the translocation be de- by the National Marine Fisheries Ser- nia "MarineResources Protection Act of clared a failure? If so, will this result in vice to restrict jet skis, which were plac- 1990," further extended the gill and tram- new resource management conflicts for ing sea otters and other protected species mel net prohibitions a§§ 8610.1-15). the species? If not, does the maintenance at risk, were upheld against a legal chal- Trammel and gill nets are now prohibited of a management zone conflict with cur- lenge by an industry trade association for at least 30 to 40 fathoms off of most rent species recovery goals?

Vo1. 13 No. 12 1996 Endangeredspecies UPDATE 77 (6) What degree of public involve- several different locations. The MMPA populations, with resulting manage- ment and consensus should be achieved defines a "population stock" as "a group ment consequences. in developing the prescription for sea of marine mammals of the same species otter recovery? or smaller taxa in a common spatial ar- Conclusion (7) What is the OSP level for this rangement, that interbreed when mature" The effort to recover sea otters from population? What is the geographic (16 U.S.C. 5 1362(11)). The FWS has the brink of extinction has made notable boundary of the population for deter- suggested that sea otters in Alaska are a progress. Nevertheless, important con- mining canying capacity and OSP? If single population stock (U.S. Fish and servation issues are yet to be resolved. If this population is delisted under the Wildlife Service 1995). the FWS and other involved parties make ESA, should it be formally designated Data collected on the movements of this necessary commitment of resources as depleted under the MMPA, and if so radio-instnunented sea otters in several to carry fornard past conservation initia- what is the significance of this classifi- parts of the range in Alaska provide no tives, the sea otter recovery program can cation for future conservation efforts? support for the idea that sea otters cap- stand as one of the crowning achieve- (8) If the population continues to tured at locations distant fromone another ments of the ESA and MMPA. The grow in numbers and expand in size, tend to inhabit a common space at any challenge that lies ahead is to ensure that what should be done to reduce conflicts time during their lives. For example, of the conservation ethic underlying the with shellfish fisheries and other re- hundreds of wild-caught radio-instru- MMPA and ESA, not political ex@- source users? mented sea otters monitored in Prince ency or the desire to avoid controversy, is (9) Do sea otters promote a healthy William Sound between 1984 and 1992, the guiding principle for sea otter man- marine ecosystem? If so, should sea none moved to adjacent habitat in the agement. otters be reestablished to promote this Kenai Peninsula (e.g., Monnett and MMPA goal regardless of whatever Rotterman 1992). Since such data do not Literature Cited population level may be required to demonstrate movements of sea otters be- Baur, D. 1991. Federally protected areas. In achieve ESA delisting or OSP? tween very distant localities throughout Natural Resources Law Handbook. Govern- In the opinion of these authors, the the Alaska range, they also provide no ment Institutes, Inc. Rockville, Maryland. 363 pp. southern sea otter remains at consider- indication that sea otters from such dis- Baur, D. 1996. Reconciling polar bear protec- able risk of endangerment,if not extinc- tant localities are interbreeding. tion under United States laws and the Interna- tion. Not enough has been done to Data from genetic studies also pro- tional Agreement for the Conservation of Polar reduce the oil spill risk, and other threats vide no support for the idea that sea Bears. Northwestern School of Law of Lewis and Clark College, Animal Law 2. underlying the original listing remain. otters from at least certain distant parts Cronin, M.A., J. Bodkin, B. Ballachey, J. Estes, The new threat of a high rate of infec- of Alaska intermingle spatially (Cronin and J.C. Patton. 19%. Mitochondrial-DNA tious disease (40% of retieved dead sea et al. 1996; Rotterman 1992). Further, variation among subspecies and populations genetic data indicate that sea otters cap- of sea otters (Enhydra lutris). Journal of otters) has emerged (see Thomas and Mammalogy 77546-557. Cole, this issue). The current popula- tured from at least three localities in Marine Mammal Commission. 1996. 1995 An- tion size is just a fraction of historic Alaska do not interbreed when mature nual Report to Congress. 235 pp. size, and it is far from a level that would (Rotterman 1992). Monnett, C. andL. Rotterman. 1992. Movements In previous MMPA proceedings of weaning and adult female sea otters in support recovery. The species range Prince William Sound, Alaska, after the TN has expanded very little in recent years, for the issuance of incidental take per- Enxon Valdez oil spill. Report. 33 pp. and it is clear that oil spill threats remain mits where the population stock defi- Rotterman, L. 1992. Patterns of genetic variabil- significant and require much greater nition has been applied, it has been ity in sea otters after severe population subdi- found that populations of other ma- vision and reduction. Ph.D dissertation. distribution of the species, as well as a University of Minnesota, Minneapolis, Min- larger population size. rine mammals in which there is inter- nesota. 228 pp. Under both the MMPA and the ESA, spersing of animals and even some U.S. Fish and Wildlife Service. 1982. Southern legal protection is given to population interbreeding do not constitute a com- sea otter recovery plan, approved. Washing- mon stock because there is an insuffi- ton, D.C. 66 pp. stocks. Because the southern sea otter has U.S. Fish and Wildlife Service. 1995. Stock been determined to be a distinct subspe- cient "common spatial arrangement" assessment sea otter, Alaska Stock. cies, the meaning of the discrete popula- (e.g., 52 Federal Register 7912, 1987, U.S. Fish and Wildlife Service. 1996. Southern tion standard as applied to this species has Dall's porpoise permit). Under this sea otter recovery plan, 1996 draft. Ventura, not yet been tested. The discrete popula- test, there appears to be no valid basis California. 41 pp. tion standard issue will become increas- upon which to support the legal find- Don Baur is a partner with the law fim of Perkins ingly important, however, as the sea otter ing of a single Alaska sea otter stock. Coie. He has served as General Counsel of the populations in California, Washington, This then raises the question of how Marine Mammal Commission and an attorney in and Alaska continue to grow. many separate stocks exist, whether any the Solicitor's Office of the Department of the The question of what constitutes a of them are depleted and, if so, what Interior. Allison Meade is a third-year student at regulatory measures are necessary. Yale Law School. She has clerked for Perkins separate seaotter population is most likely Coie and the Sierra Club Legal Defense Fund. to be confronted first in Alaska, where The answers to these questions will Lisa Rottennan is an ecologist and geneticist groups of sea otters are currently found in have application to other sea otter who has studied sea otters since 1984.

78 Endangered Species UPDATE Vo1, 13 No. 12 1996 Estimating the Historical Abundance of Sea Otters in California Douglas P. DeMaster, Catherine Marzin, and Ron J. Jameson

Prior to commercial exploitation, the Marine Mammal Protection Act, a females, and dependent pups has re- the estimated abundance of sea otters population is considered depleted if its mained relatively constant in the center (Enhydra lutris) in the North Pacific current abundancelevel is below arange of the range. Therefore, it should be Ocean was between 150,000 (Kenyon of population sizes referred to as the possible to estimate K by having an 1969) and 300,000 (Johnson 1982). Sea optimum sustainable population (OSP) estimate of the equilibrium density of otters historically ranged from Baja Cali- level (Gerrodette and DeMaster 1990; sea otters per linear mile of coastline or fornia along the Pacific coast northward see Baur et al., this issue). As Congress square mile of available habitat from the to Prince William Sound, Alaska; south- intentionally left the definition of OSP central portion of their current range westward along the Alaska Peninsula, vague, an operational definition has and knowing the amount of available throughout the Aleutian Islands, Pribilof evolved where the lower end of the OSP habitat in the state (Gerrodette and Islands, and Commander Islands to range is assumed to occur at approxi- DeMaster 1990). Kamchatka; and then southward through mately 60% of the maximum popula- the Kuril Islands to Sakhalin and tion size the environment will support Methods Hokkaido (Kenyon 1969; see Ander- (i.e., K). Therefore, from a manage- The maximum number of sea otters son, this issue). Prior to commercial ment perspective, it is important to have that the marine environment in Califor- exploitation in California, sea otters oc- a reliable estimate of K. nia will support (K) was estimated by cupied the waters off the entire coast of Unfortunately,estimating K is very first determining the equilibrium den- California. The population was esti- difficult. As noted by Gerrodette and sity of sea otters in each of three habitat mated to have included between 16,000 DeMaster (1990), there are only ahand- types, and then determining the amount to 18,000 animals (California Depart- ful of methods that can be applied to this of each habitat type that exists in Cali- ment of Fish andGame (CDFG) 1976a). problem: (1) back-calculating histori- fornia. Due to a lack of suitable alternatives, cal abundance levels, based on a current The following values for equilib- this estimate has become the best avail- estimate of abundance, a history of hu- rium density were made using survey able estimate of the current carrying man-related annual removals, and in- data as of 1992 (Marzin and DeMaster capacity (K) of sea otters in California. formation regarding the relationship be- 1992):(1) 13.21 otters per square nauti- Further, because the range of sea otters tween abundance and net productivity; cal mile (nm2; nm=1,852 m) for rocky is currently discontinuous between Cali- (2) using historical estimates of abun- habitat; (2) 6.95 otters per nm2 for mixed fornia and Washington, evidence that dance that were made prior to the onset habitat; and (3) 1.19 otters per nm2 for sea otters in California should be af- of commercial exploitation; or (3) di- sandy habitat. The equilibrium density forded sub-specific status (U.S. Fish rectly estimating the current carrying of otters for sandy habitats was based on and Wildlife Service 1996; see Ander- capacity, based on information about the density of sea otters in Monterey and son et al., this issue), and a lack of factors which limit population growth. Morro Bays. The equilibrium density alternative historical estimates of abun- All of these require information that is of sea otters in mixed habitat was based dance for sea otters along the west coast typically not available. For sea otters in on the density between Aiio Nuevo and of the United States,the 16,000to 18,000 California, techniques Numbers 1 and 2 the Santa Maria River, while for rocky abundance estimate has also been used are easily dismissed as there are no habitat the estimate was based on the as the best available estimate of K for reliable abundance estimates from the number of sea otters between Cayucos the population of sea otters referred to 1700s, and there is no reliable informa- Point and Monterey Bay. as southern (or California) sea otters. tion on the catch history of sea otters The amount of area available to The objective of this paper is to from the late 1700suntil the early 1900s. sea otters in California by habitat type refine the 1976 estimate of K for sea At first blush, one might also aban- was estimated based on the assump- otters in California. To some, estimat- don the approach of estimating current tion that sea otters cannot effectively ing K for a population that currently K based on knowledge regarding fac- forage in water depths greater than occupies less than 250 miles of coast- tors that limit or regulate population 130 ft (40 m). This threshold was line in central California and includes growth. Fortunately, the recovery of selected based on Ralls et al. 1995, approximately 2,400 animals (U.S. Fish sea otters has occurred primarily as a where they reported that juveniles, and Wildlife Service 1996) may seem result of range expansions initiated by which usually forage in water deeper pointless; however, having a reliable peripheral groups of males (Riedman than adults, typically do not feed in estimate of K is important for the fol- and Estes 1990), where the core density water deeper than 160 ft (49 m). In a lowing reason. Under the provisions of of adult males and females, juvenile preliminary exercise to estimate K, it

Vol. 13 No. 12 1996 Endangered Species UPDATE 79 information provided in nautical charts and personal experience. Following the procedure de- scribed above, the total area avail- able to sea otters was estimated to equal 2,275 nm2. By habitat type, the following areas were calculated: rocky (669 nm2), mixed (480 nm2), and sandy (1,126 nm2). Based on these results, almost 50% of the available habitat for sea otters in California is low quality, while less than 30% of the available habitat is high quality.

Results and discussion The estimated number of sea otters that could be supported by the marine environment in California was 13,513 (see Table 2). The weighted average density of sea ot- ters in California was approximately 5.9 sea otters per nm2, based on an estimate of a total area of 2,275 nm2. The estimate of K was based on the assumption that the habitat quality of SFB is the lowest density of the three habitat types (i.e., sandy habitat). If it were assumed that the habitat quality was intermediate be- tween the sandy and rocky habitat types (i.e., mixed), the resulting es- timate of sea otters that could be supported within SFB is 2,23 1 sea otters (321 nm2 multiplied by 6.95 otters per nm2). Incorporating this assumption into the estimate of K would increase the estimate to 15,362 sea otters. For a variety of reasons, it is difficult to predict the Table 1. Summary of geographical areas in California sultable for sea otters, where each area equilibrium density of sea otters in has been assigned a habitat type (and associated equillbrlum density- D,). The surface area SFB, including uncertainty regard- (nml) for a particular geographical area was calculated, aSSuming a maxlmum feeding depth ing the number of sea otters corn- of 130 R (40 m). The number of otters per area was calculated as the product of 4 and area. mercially harvested in SFB, the un- was determined that the estimate was of 130 ft and along the entire Califor- known impact of pollutants on the envi- relatively insensitive to the choice of nia coastline, including the Channel ronment, and the unknown influence of the depth contour between 30 ft (9 m) Islands and San Francisco Bay (SFB), fisheries on the benthos in SFB. and 160 ft. For example, if the 160 ft was estimated using the FORTRAN If we had assumed the equilibrium contour had been selected as the off- subroutine SPHAREA (Forney 1988). density of sea otters in California was shore boundary, the resulting density Thirty-nine discrete areas were equal to the existing density between would be lower than if the 130 ft identified off the coast of California, Cayucos Point and Monterey Bay (i.e., contour had been selected, but the ran ing in size from 2 nm2 to 321 13.21 otters per nm2), the resulting es- available habitat for the former would nm 4 , and a habitat type was assigned timate of K would have been over 30,000 be increased relative to the latter, and to each area (see Table 1). The spe- otters. This estimate is likely to be the resulting estimate of available cific characterization of an area as positively biased because the average habitat would have been similar. The being sandy, mixed or rocky was done quality of the habitat used to estimate estimate of surface area out to a depth by one of the authors (RJJ) based on the equilibrium density in "typical"

80 Endangered Species UPDATE Vo1. 13 No. 12 1996 animals (see Table I), respectively. An Habitat Type Density (lnm2) Area (nm2) Number of otters extensive application of this technique @i) (Ai) (Ai * Di) is reported in Marzin (1996). 1. Rocky 13.21 669 8837 2. Mixed 6.95 480 3336 Literature Cited 3. Sandy 1.19 1126 1340 California Department of Fish and Game. 1976a. Total 2275 13,513 A proposalfor sea otter protection and research, and request for the return of management to Table 2. Estimated number of sea otters that could be supported by the State of California. Unpublished 2 volume habitat type. report. California Department of Fish and Game. 1976b. Comments on the Friends of the Sea Otter's rocky habitat is considerably better than Conclusions and critique of the State of California's Sea Otter Proposal. 1976.44 pp. the average quality of habitat through- recommendations Forney, K. 1988. Contour mapping and the out the state (Marzin 1996). In fact, Under the existing Marine Mam- calculation of areas between 10m depth based on our analysis, the average qual- mal Protection Act, the southern sea contours along the coast of California, Oregon, ity of habitat in waters off the coast of otter population should be considered and Washington. National Marine Fisheries Service, NMFS SWFSC Administrative California is marginally less than the depleted as long as its abundance is less Report LJ-88-23. LaJolla, California. classification that we referred to as than 60% of K. At present, therefore, Gerrodette, T. and D.P. DeMaster. 1990. "mixed." It should also be noted that in the best estimate of the lower bound for Quantitative determination of optimum the original estimate of K for sea otters being depleted is 60% of 13,513, or sustainable population level. Marine Mammal Science 6(1):1-16. in California by CDFG (1976a), it was approximately 8,100 animals. Johnson, A.M. 1982. The sea otter, Enhydra assumed that: (1) the equilibrium den- We believe our preliminary esti- lutris. Pages 521-525 in Mammals of the Sea. sity of sea otters was approximately 12 mate of between 13,500 and 15,400 Food and Agricultural Organization Fisheries sea otters per nm2, and (2) the amount animals is the best available estimate of Service. 5, Vol. IV. Kenyon, K.W. 1969. The sea otter in the eastern of available habitat was approximately K for sea otters in California at this time Pacific Ocean. North American Fauna, Number 1,300 to 1,500 nm2. The 12 sea otters for the following reasons: (1) the cur- 68.352 pp. per nm2 figure was derived by dividing rent information on the existing density Marzin, C.G. 1996. Alternative management the number of sea otters known to occur of sea otters was used; (2) equilibrium options for the California sea otter population: An interdisciplinary approach. M.S. thesis, between Seaside and Morro Bay by the density estimates were stratified by habi- University of Washington, Seattle, area between Seaside and Morro Bay tat types and based on recent informa- Washington. 85 pp. out to a depth of 120 ft (California tion regarding the distribution of sea Marzin, C.G. and D.P. DeMaster. 1992. Department of Fish and Game 1976b). otters in California; (3) estimates of Estimating the carrying capacity of sea otters (Enhydra lutris) along the California coast. It was assumed in using the 12 sea otters maximum foraging depth were based AppendixD inU.S. Fish and Wildlife Service. per nm2 that it accounted for all habitat on current information on foraging be- Southern sea otter recovery plan, 1996 draft. types, including rocky, sandy, and mud havior, as determined from radio-te- 41 PP. bottoms (California Department of Fish lemetry; and (4) estimates of total habi- Palmisano, J.F. and J.A. Estes. 1977. Ecological interactions involving the sea otter. Pages and Game 1976b). Given that the aver- tat available were based on all of the 527-567 in M.L. Merritt and R.G. Fuller, age quality of habitat reported in this available habitat types in California. editors. The Environment of Amchitka study was 5.9 sea otters per nm2, the Additional studies are needed to test the Island, Alaska. U.S. ERDA, TID-26712. estimate of 12 sea otters per nm2 should statistical validity of the assumed equi- Springfield, Virginia. Ralls, K., B.B. Hatfield, and D.B. Siniff. 1995. also be considered positively biased. librium density for each of the three Foraging patterns of California sea otters as Finally, while estimates of equilibrium habitat types and the reliability of the indicated by telemetry. Canadian Journal of densities of 10 to 15 sea otters per nm2 characterization of the coastal marine Zoology 73:523-531. (based on a maximum feeding depth of habitat. For example, it would be useful Riedman, M.L. and J.A. Estes. 1990. The sea otter (Enhydra lutris): behavior, ecology, and 180 ft (55 m)) have been reported in to have more recent estimates of the naturalhistory. U.S. Department of the Interior, Alaska (Kenyon 1969), with short-term density for each habitat type, as well as Fish and Wildlife Service. Biological Report (i.e., non-equilibrium) density estimates estimates of the associated variance. 90(14). Washington, D.C. 126 pp. reaching in excess of 50 animals per Finally, the technique described in U.S. Fish and Wildlife Service. 1996. Southern sea otter recovery plan, 1996 draft. Ventura, nm2 (Palmisano and Estes 1977), it this paper could be used to provide California. 41 pp. seems unreasonable in the face of the guidance as to the number of sea otters available information on the distribu- that might be expected to exist within a Douglas P. DeMaster works with the National Marine Mammal Laboratory, 7600 Sand Point tion and density of sea otters in Califor- specified area. For example, the equi- Way, NE,Seattle, Washington981 15. Catherine nia to use information on Alaska otters librium number of sea otters that could Marzin is with the Office of the Oceanographer in estimating K for sea otters in Califor- occupy the area surrounding the Chan- of the Navy, Naval Observatory, 3450 nia (California Department of Fish and nel Islands or areas 11 through 25 (Pt. Massachusetts Ave, NW, Washington, D.C. 20390. Ron J. Jameson works with the National Game 1976a, b). Conception to Pt. San Pedro) was esti- Biological Survey, 200 SW 35th St, Corvdlis, mated to equal 2,774 animals and 3,300 Oregon 97333.

Voi. 13 No. 12 1996 Endangered Species UPDATE 81 The State of California's Role in the Conservation of Sea Otters and Other Aquatic Resources Fred Wendell

The State of California plays an they have been prioritized. sistent rate. The State augmented its important role in the protection and (1) Maintain sufficientpopulations protection by establishing the Sea Otter management of California's sea otter of all species of aquatic organisms to Game Refuge in 1941 (see Figure 1). population. However, that role has insure their continued existence. The refuge boundaries were expanded changed substantially over the years, (2) Recognize the importance of to include virtually the entire sea otter from primary responsibility for protec- the aesthetic, educational,scientific, and range in 1959. However, with continued tion and management of sea otters to a nonextractive recreational uses of growth came controversy and eventually role secondary to the federal govern- aquatic resources. the recognition that achieving all of the ment. Within California State govern- (3) Maintain sufficient resources objectives for the conservation of aquatic ment, responsibility for wildlife to support a reasonable sport use. resources might require a modification of resources, including seaotters, rests with (4) Encourage the growth of local the CDFG's protective posture. the California Department of Fish and commercial fisheries, consistent with Game (CDFG). The CDFG is part of aesthetic, educational, scientific, and Otter-fisheries conflict the Resources Agency which oversees recreational uses of such living re- In the early 1960s, views differed the management of California's natural sources, and to foster the use of unused within the CDFG about the relative in- resources. Overseeing and regulating resources. fluence of sea otter predation and hu- policies that guide the CDFG in fulfiig (5) Manage fisheriesunder the state's man consumptive uses on the loss of red its public trust responsibility are provided jurisdiction on a basis of adequate scien- abalone (Haliotis rufescens) fisheries. by the State Legislatureand the California tific information promptly promulgated The prevailing view was that human over- Fish and Game Commission. Thus, the for public scrutiny with the objective of exploitation was responsible for the loss state's public trust responsibilities are maximizing a sustained harvest. of abalone fisheries within areas reoccu- expressed through the CDFG. (6) Encourage the development of pied by sea otters. However, the ongoing commercial aquaculture. controversy and legislative action (de- CDFG management policies Broadly translated, these objectives scribed below) prompted a reevaluation The CDFG's mission is to serve the espouse a conservation-oriented per- of that subjective appraisal and the status public by conserving the state's living spective. How that perspective has been of the sea otter population. natural resources for their ecological expressed in action has changed appre- In 1967, the State Senate passed a values and for their use and enjoyment ciably through the course of the sea resolution directing the CDFG to deter- by the public today and in the future. otter's recovery in California. mine the feasibility of containing the The foundation for this mission is con- sea otter population in an effort to pro- tained in policies established by the History of California's role in sea tect the existing recreational and com- State Legislature over the last several otter protection mercial abalone fisheries while decades. When considering the conser- Early in the population's recovery maintaining the sea otter population vation of aquatic resources, the Legisla- from over-exploitation (see Anderson (Bissel and Hubbard 1968). In compli- ture declared it to be state policy to et al., this issue),just after the turn of the ance, the CDFG initiated studies to encourage the conservation, mainte- century, the sea otter population was evaluate the status of the population and nance, and utilization of the living re- provided complete protection under state to obtain the background biological in- sources of the ocean for the benefit of all law (California Fish and Game Code, formation necessary for safe manage- the citizens of the state, and to promote Section 4700). Complete protection ment of the seaotter population. Studies the development of local fisheries in was deemed to be commensurate with were also conducted to assess the ef- harmony with the conservation of the the population's precarious status. The fects of sea otter foraging on shellfish ocean's living resources (CaliforniaFish emphasis was placed on achieving the resources, with an emphasis on abalone and Game Code, Section 1700). first objective mentioned above, in this fisheries (Ebert 1968; Wild and Ames Six objectives were delineated to case to establish and maintain a suffi- 1974; Wendell et al. 1986). give guidance in carrying out the policy cient number of sea otters to insure the Sea otter range expansion, between for conserving aquatic resources. These population's continued existence in state 1967 and 1972, into the state's most objectives provide the foundation for waters. That emphasis remains un- productive red abalone fishing grounds the CDFG's ongoing evaluations of al- changed. With protection provided at near Point Estero afforded an opportu- ternative sea otter management strate- the turn of the century by state law and nity to assess the status of the red aba- gies. The objectives are abbreviated internationaltreaty, the population grew lone resource before, during, and after below and appear in the order in which and expanded its range at a fairly con- reoccupation of the area by sea otters.

82 Endangered Species UPDATE Vol. 13 No. 12 1996 This research yielded compelling evi- parently incompatible uses of the state's the objectives of protecting the sea otter dence that sea otters were responsible shellfish resources. This concept, sug- population and providing for human for the loss of recreational and commer- gested in the 1967 State Senate resolu- uses of shellfish resources. As a conse- cial abalone fisheries within the sea tion, has come to be known as zonal quence, the CDFG's role shifted to one otter's range (Wendell 1994). The pro- management. that emphasized advocacy of zonal man- gression in the precipitous decline in In 1968, the CDFG began conduct- agement as well as sea otter protection. abalone densities closely corresponded ing research to evaluate capture, tag- to the southward progression of sea ging, and transport techniques for sea Southern sea otters and the otter foraging activity in the area. otters (Odemar and Wilson 1969). The Endangered Species Act effort was designed to assess the utility This historical perspective is rel- Zonal management of translocating otters from the area of evant because it gives the background Clarifying the factual basis for the conflict at the range periphery back into for the CDFG's recommendations con- resource-use conflict underscored the the well-established range. The effort cerning the population's possible listing problem in achieving the state's policy established basic translocation proto- under the Endangered Species Act objectives if sea otter range expansion cols but did little to test the technical (ESA). While the CDFG did not estab- continued. The only management strat- feasibility of zonal management before lish what measures would be necessary egy that appeared to have potential for the concern over the loss of commercial to protect the sea otter population from insuring the continued existence of a and recreational shellfish fisheries be- the threat of a large-scale oil spill within sea otter population in state waters (ob- came a secondary issue. a zonal management context, it con- jective Number 1) and sufficient shell- cluded that a sufficient number of sea fish resource for human use (objectives Shifr to federal control otters existed to insure the population's Numbers 3 and 4) was to establish geo- The passage of the federal Marine continued existence (CaliforniaDepart- graphically separate zones for these ap- Mammal Protection Act (MMPA) in ment of Fish and Game 1976). As a 1972 placed re- consequence, the CDFG recommended sponsibility for against the listing of this population sea otters under under the ESA. The U.S. Fish and federal control Wildlife Service nevertheless listed the and imposed a population in California as threatened. legislative man- While the CDFG questioned the date that fo- assessment that the population's status cused on in- was precarious, the response to the creasing the listing proposal did not signal a change numbers of sea in the CDFG's policy on protection of otters within sea otters. When protection was state waters (see warranted, action was taken. A case in Baur et al., this point is the legislation to limit the issue). This dra- accidental drowning of sea otters in matically large-mesh set nets (California Fish and changed the Game Code, Section 8664.5). The CDFG's role. accidental drowning of sea otters in gill Addressing the and trammel nets, used to catch state's other California halibut (Paralichthys policy objec- californicus), was identified as a source tives is not eas- of mortality that had probably increased ily achieved un- as the sea otter population expanded der the MMPA into areas of intense fishing. The mandate. The estimated number of otters drowned single-species annually during a two year study period emphasis effec- in the early 1980s (80 otters) was of a tively delayed magnitude sufficient to contribute the irnplementa- significantly to the lack of sea otter tion of any form population growth during that time of zonal man- period. Legislative action created a agement de- spatial separation between the fishing signed to achieve activity and sea otters by closing waters Figure 1. Locationof California's seaotter game refuge as originally established in 1941 (cross hatch) and expanded in 1959 (diagonal a that less than 30 fathom depth to that fishery. hatch). recognized both The level of accidental drowning

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Vol. 13 No. 12 1996 Endangered Species UPDATE 83 declined to virtually zero; however, the otter distribution because of the conflict for sea otters within California waters. fishery was not sustainable with the with human uses of shellfish. It created However, our conservation efforts will depth restriction and essentially a workable compromise that generated not end with achieving that goal. Rec- collapsed within a few years. The the legal authority necessary to attempt ognizing that, we should ensure that a balance between competing objectives to maintain the beneficial uses of both long-term perspective is built into our cannot favor human uses of the state's the state's sea otter population and shell- conservation planning process. It is resources if those uses conflict with fish resources. from that perspective that I offer the insuring the existence of a viable sea following specific recommendations. otter population. Rather, the CDFG's Conclusion and (1) Initiate adialogue on long-term opposition to the listing reflected recommendations management of aquatic resources that concern over the institution of yet The implementation of Pub. Law provides opportunity for involvement another single-species mandate that had 99-625's containment management pro- by all interested parties to fully discuss significant ramifications on the state's visions afforded the first opportunity to the merits of zonal management. ability to manage its wildlife resources. evaluate the technical feasibility of zonal (2) Develop funding mechanisms Safeguarding the population of sea management. The effort achieved limited to support the testing and, if subse- otters in California is a common goal for success while demonstrating that ongo- quently found to be appropriate, the all of the regulating agencies involved. ing efforts would likely prove to be costly implementation of zonal management. However, the CDFG also recognizes that and labor intensive. However, the effort (3) Initiate studies that focus on determining what constitutes a safe popu- raised more questions about the technical the efficacy and safety of limiting sea lation level has been and will likely con- feasibility, efficacy and safety of zonal otter population growth potential through tinue to be a contentious process. The management than it answered. contraception. CDFG is also concerned that the manage- Subsequent CDFG actions related ment strategy proposed in the second re- to sea otter management will continue Literature Cited Bissell,H.andF. Hubbard. 1968.Reports on the sea covery plan moves away from a recovery to emphasize protection for sea otters strategy that considered impacts to hu- otter, abalone and kelp resources in San Luis and advocacy for conservation ap- Obispo andMonterey counties and proposals for man uses of shellfish resources. In that proaches that consider human uses of reducing the conflict between the commercial regard, the second recovery plan rejects a aquatic resources. The CDFG's protec- abalone industry and the sea otter. California Fish and Game Report requested by Senate broadly supported compromise developed tive efforts will likely focus on oil spill to implement the original recovery plan Concurrent Resolution 74 of 1967 Legislative contingency planning and reducing the Session. that addressed the CDFG's desire for bal- risk associated with oil spills. Whether California Department of Fish and Game. 1976. ance between competing and conflicting a balance is possible between sea otter A proposal for sea otter protection and re- search, and request for return of management uses of the state's shellfish resources. In protection and providing a continuing fact, the second recovery plan questions to the State of California. Unpublished 2 vol- resource that will support existing shell- ume report. the validity of the view that sea otter fish fisheries will now likely depend on Ebert, E. 1968. California sea otter - census and predation has directly caused the loss of how the MMPA is administered with habitat survey. Underwater Naturalist. Win- shellfish fisheries. Thus, where consider- ter. Pages 20-23. regard to socioeconomic issues. The Odemar, M.W. and K.C. Wilson. 1969. Results ation of human uses of affected resources MMPA seems to have the flexibility, of sea otter capture, tagging and transporting will balance against additional sea otter however its expression will require broad operations by the California Department of population growth remains to be seen. public support. Fish and Game. Pages 73-79 in Proceedings This raises the question of whether the Sixth Annual Conference on Biological Sonar In the CDFG's view, a balance that and Diving mammals, Stanford Research In- recreational andcommercialshellfish fish- considers all of the state's policy objec- stitute. Menlo Park, California. 113 pp. eries that are an important part of tives would provide for more diverse and, Wendell, F. 1994. Relationshipbetween sea otter California'scolorful heritage will survive. potentially, better uses of resources by range expansion and red abalone abundance The ESA's inability to consider the and size distribution in central California. considering both human and other spe- California Fish and Game 80:45-56. socioeconomic impacts of recovery ac- cies' needs. The CDFG realizes that suc- Wendell, F., R. Hardy, J. Ames, and R. Burge. tions has contributed significantly to cessful implementation will require 1986. Temporal and spatial patterns in sea the polarized positions taken by groups partnerships among a variety of interests. otter, Enhydra lutris, range expansion and in concerned with the sea otter-shellfish the loss of Pismo clam fisheries. California One crucial component in creating those Fish and Game 72:197-212. fishery conflict. Pub. Law 99-625 and partnerships is to achieve acommon view, Wild, P. and J. Ames. 1974. A report on the sea the translocation plan (see Baur et al., or at least a workable compromise, on otter, Enhydra lutris , in California. Califor- this issue) were supported by the CDFG reasonable human uses (aesthetic, edu- nia Fish and Game Marine Resources Techni- cal Report 20.93 pp. because they recognized socioeconomic cational, scientific, nonextractive, and impacts. In effect, Pub. Law 99-625 consumptive) of natural resources in acted as an interim long-term manage- the marine environment. ment plan by providing the sea otter Fred Wendell is a Marine Biologist with the Sea It is likely that sea otter conserva- Otter Research Project at the California population with an additional safeguard tion efforts under state and federal law Department of Fish andGame, 213 Beach Street, while recognizing the need to limit sea will be successful in securing a future Morro Bay, California 93442.

84 Endangered Species UPDATE Vol. 13 No. 12 1996 Saving the Sea Otter Population in California: Contemporary Problems and Future Pitfalls Glenn R. VanBlaricom

California sea otters first entered Problems emerging from other at al., this issue). An obvious advantage of the biopolitical arena in the 1960s when articles this process is that reduced spill risks are the conflict developed between the red Reducing the risk of oil spills in of benefit to everyone involved in coastal abalone (Haliotis rufescens) fishery and California waters zone management: oil companies and the growing sea otter population. Since Preceding papers include accounts related industries, tourism interests, ma- that time the central issues of concern of considerable effort devoted to mitigat- rine sanctuary programs, commercial and for sea otter conservation have been ing the consequences of a drastic reduc- recreational fisheries, local governments, conflicts with shellfisheries and, later, tion in sea otter numbers. Such efforts transportation regulatory agencies, con- the perception of risk associated with follow largely from the perception that servation-oriented NGOs, university re- marine oil development and transport. a major oil spill is possible in California searchers, and resource agencies. There Concern about possible oil spills even- sea otter habitat and could affect a sig- are few negatives other than increases in tually placed California sea otters on nificant portion of the population operational costs for large vessels, and the list of threatened species pursuant to (VanBlaricom and Jameson 1982; possibly increasedenforcementcosts. The the Endangered Species Act (ESA) of Bonnell et al., this issue), and the recog- megaliabilities of damage assessment, 1973 as amended. The listing provided nition that oil spills cause significant restoration, and litigation falling to parties an early example of the conundrum that mortality in sea otter populations responsible for oil spills (witness the case has bedeviled conservationefforts since (Garrott et al. 1993; DeGange et al. of the &on Valdez)argue that increased passage of the ESA: Here was a popu- 1994;Loughlin 1994;Brody et al. 1996). operational and enforcement costs should lation viewed simultaneously as des- Three specific types of mitigation be the preferred alternative. perately in need of protection by some, effort are discussed: techniques and fa- At least one objection to the risk and as a socioeconomicmenace by oth- cilities for rescue, treatment, and reha- reduction approach can be imagined. The ers. Although other issues have since bilitation of sea otters (see Jessup et al.; oil industry and the related large-vessel emerged, discussions of the conserva- Williams and Williams, this issue); strat- transportation industry are expansive and tion of California sea otters have to date egies for captive breeding (see Brennan multi-faceted, thus, "negotiating with the invariably focused primarily on shell- and Houck; Duffield et al., this issue); industry" will in fact be a daunting logis- fisheries or oil spills. Now we approach and development of a genome resource tical challenge. However, the transloca- a transition, from which the range of bank (see Long et al., this issue). Each tion of sea otters to San Nicolas Island issues broadens and their complexity approach promises a significant contri- faced comparably intimidating obstacles. deepens. bution toward enhancement of a popu- Despite substantial administrative and I have two purposes here. The first lation that has been precipitously technical challenges, political complexi- is to provide a synopsis of key issues reduced by an oil spill. ties, and the vocal disapproval by some identified in the other papers of this The efficacy and efficiency of post- interest groups, managementauthority was publication and briefly discuss their sig- spill mitigation measures for sea otter able to build a plan that led to project nificance. The second purpose is to conservation havebeen hotly debated (e.g., approval (see Benz, Attempts to Reintro- look beyond current controversies and VanBlaricom and Gornall 1989; Arnes duce, this issue). anticipate issues emerging in the con- 1990; VanBlaricom 1990, Estes 1991). servation politics of sea otters as we Even among antagonists there is broad What should the optimum sustainable enter the new millennium. The central agreement, however, that measures pre- population level be? assumptionthroughout this paper is that venting oil spills from occurring likely are The ESA and MMPA provide key sea otters will be taken off the endan- much more effective tools than any mea- legislative guidelines for conservation of gered species list and will be declared at sures designed to restore sea otter popula- marine mammal populations such as Cali- an optimum sustainable population tions from spill-related reductions. There fornia sea otters. The presence of listed (OSP) level, pursuant to the Marine is a clear need for involved agencies, populations can result in far-reachinghabi- Mammal Protection Act (MMPA) of researchers, and non-governmental orga- tat protection policies and can limit many 1972 as amended, within the next few nizations (NO)to develop a joint plan kinds of economic activity within pre- decades. As a consequence new prob- for reduction of oil spill risk, and to enter ferred habitat (e.g., Clark, this issue). Thus lems will move to the forefront. In my negotiations with the large vessel industry it is desirable to "recover"listed popula- opinion these problems will be vexing, to implement new standards from which tions in order to facilitate conservation possibly even intractable. Thus, it is not sea otter conservation will benefit. The and perhaps to reduce impediments to too soon to begin considering ap- new standards must focus on moving various options for management and eco- proaches to their resolution. vessel traffic farther offshore (e.g.,Bonnell nomic enterprise.

Vol. 13 No. 12 1996 Endangered Species UPDATE 85 For the ESA, definition of listing with sea otter conservation goals. Given state-federal relationship is that it has criteria typically has fallen to Recovery the gap between these estimates I see an created a template for polarization of pub- Teams appointed on a case-by-case ba- obvious potential for discord. lic interest in sea otter conservation and sis. For California sea otters the ap- The MMPA is ambiguous in defin- management. Given the stronglydichoto- pointed Recovery Team has proposed ing minimum OSP levels, implying sub- mous, apparently irreconcilable positions that endangered status is appropriate for stantial flexibility in approaching the of CDFG and FWSAJSGS on many sea a population size less than 1,850 ani- problem. Thus the opportunity is avail- otter conservation issues, non-govern- mals, and threatened status for a popu- able for setting OSPlevels that accommo- mental interest groups and stakeholders lation size between 1,850 and 2,650 date diverse interests and concerns. I urge have gravitated to one side or the other. animals. The MMPA mandates that management authority and affected par- Rather than developing a unified front populations of marine mammals smaller ties to begin, now, the process of negoti- necessary to influence decision-makers than the OSP level are to be listed as ating toward a consensus OSP range. and move forward on the implementation depleted, subject to a petition process of consensus conservation policy, each (see below). Again, specific listing Jurisdictional strife: template for side instead has invested substantial en- criteria are not a part of the legislation, polarization ergy in attempts to discredit the views and but the customary management prac- Since 1972 there has been a consis- goals of the other side, with the result that tice has been to set a minimum OSP size tent pattern of dissension between Cali- decision-makers have done nothing on at 60% of carrying capacity (K; see fornia Department of Fish and Game many sigmlicant issues. DeMaster et al., this issue). (CDFG) and U. S. Fish and Wildlife Ser- It is disturbing to find new evi- Marine mammal populations listed vice (FWS; note that the research division dence of the destructive polarization either as endangered or threatened un- of FWS, formerly known as the National process. For example, Jessup et al. (this der ESA are by default categorized as Biological Service, became part of the issue) summarize the recent progress in depleted under MMPA. Removal from U.S. Geological Survey (USGS) in 1996) the development of facilities and proce- lists defined by ESA also automatically with regard to the conservation of sea dures for care of oiled marine wildlife in removes the depleted designation as otters. The preemption of state manage- California. The Oiled Wildlife Care defined by MMPA, even if the popula- ment of sea otters by MMPA in 1972 Network (OWCN), managed by CDFG, tion size is less than 60% of K. An greatly complicated the efforts of CDFG is a good model of cooperative effort approved petition is required for popu- to find a solution for sea otter-shellfishery among potentially disparate agencies, lations delisted under ESA to be listed conflicts. The listing of California sea NGOs, and other interests, and reflects as depleted under MMPA (see Baur et otters as threatened in 1977 was, in the the lesson of the Exxon Valdez disaster: al., this issue). view of CDFG, an unjustifiable exag- rescue and rehabilitation facilities and For my purposes here I assume that geration of oil spill risk relative to the procedures cannot possibly succeed if such a petition will follow immediately population size and distribution of sea they are assembled post-spill. Unfortu- after the delisting of the sea otter popu- otters (see Wendell, this issue). These nately, the 1996 draft revised Southern lation. This circumstance would make events fostered an understandable resent- Sea Otter Recovery Plan (Recovery the delisting meaningless in a manage- ment of federal management authority, Plan), prepared at the behest of FWS, ment context, because depleted status injecting distrust and bitterness to interac- makes a strongly negative editorial cat- under the MMPA carries many of the tions of state and federal managers and egorization of the type of approach rep- same restrictions as the ESA, and could researchers. Efforts by federal agencies resented by OWCN. The draft Recovery limit management options designed to to introduce new research hypotheses and Plan offers no analytical justification balance conservation goals and socio- management concepts only engendered for the stated position. Thus the Recov- economic needs. Thus, in my view, the further skepticism and division, with the ery Team, and by extension FWS, ap- central recovery issue relates to MMPA, result that federal staff also became suspi- pear to be arbitrarily categorizing as not ESA, and specifically is: What is cious and distrustful of state positions on worthless the most prominent element OSP level for California sea otters? key issues. Because there has been rela- of the CDFG strategy for dealing with There is a range of views regarding tively little turnover in staffing of federal oil spills in California sea otter habitat. the appropriate criteria for determina- and state sea otter management and re- Aconsensus agreement on OSPlevel tion of the OSP size. DeMaster et al. search since the late 1970s, there have probably is not attainable if the dysfunc- (this issue) present a largely ecologi- been few stimuli for embittered individu- tional relationship of CDFG and FWSI cally-based argument for a minimum als on either side to seek a more positive USGS persists. Public polarization and value of 8,100 animals. Wendell (this approach to resolution of mutually sig- decision-making stagnation will follow issue) argues for considerationof socio- nificant issues. Thus, federal-state inter- inevitably from continued failure of state economic as well as ecological issues in actions regarding California sea otter and federal authorities to place high value setting a minimum OSP level, implying conservation 0fte.n have shown all the on effectivecooperation. Third-party me- that a value closer to ESA thresholds sophistication of a rugby match on the diation may be a desirable approach in would be preferred in order to accom- mudflats of Elkhorn Slough. moving CDFG-FWSIUSGS interactions modate diverse human concerns along The real tragedy of the dysfunctional to a more constructive realm.

86 Endangetmi Species UPDATE Vol. 13 No. 12 1996 biologically and structurally,and provide more benefits in terms of secondary avail- ability of fixed carbon (e.g., Estes and Duggins 1995). This model has become dogma for much of the coastal Pacific Rim, especially in Alaska, but it remains in dispute in California (McLean 1962; VanBlaricom 1984; Foster and Schiel 1988; Estes and Duggins 1995). The alternative view, articulated by Foster and Schiel(1988), is that sea otters are only one of a number of factors that influence kelp forest structure at any particular location. Foster and Schiel argue that our capability for predicting the otter-urchin-kelp relationship is weak and that the model is overgeneralized, and possibly not ap- Photograph by Jeff Foott plicable, for California coastal habitats. Omissions of note management goals. As the population Resolution of the dispute is impor- There are two important problems continues to grow, it may be necessary to tant for two reasons. First, both ESA and receiving only minimal discussion in this modify survey methods for at least two MMPA mandate an understanding of the issue. The first is the method currently reasons. First, an expanding range will ecological connections between sea ot- used for assessing the size and dispersion increase the d*culty in completing a ters and their ecosystems. Because kelp of the California sea otter population (see count in a short period, which is important have profound effects on habitat for other Bodkin and Ballachey, this issue). This to ensure that survey results are not biased coastal organisms (e.g., Duggins 1988; method was developed by FWS and by significant movements of animals dur- Duggins et al. 1989), appropriate man- CDFG in the early 1980s, primarily ing the survey period (R. Jameson, per- agement of sea otters demands that the through the initiative of R. J. Jameson, sonalcommunication). Second, increases dispute be resolved. Second, kelp is har- and includes two components. Most of in range likely will change the proportion vested and supports a simcant eco- the current seaotterrangecanbe censused of the population that can be surveyed by nomic enterprise in California (e.g., by ground observers because of the avail- each of the two component methods. Such Tarpley and Glantz 1992). Wendell (this ability of State Highway 1 andtheprecipi- changes will alter the correlation between issue) argues that human recreational and tous nature of the coastline. Less accessible total number counted and actual popula- commercial enterprises in coastal marine portions of the range, such as those off tion size in an unknown manner. In turn, waters should be significant factors in the Santa Cruz County and south of Pismo these changes affect the accuracy of cal- determination of OSP level for California Beach, are surveyed by aircraft. Detec- culated trends in population size and alter sea otters. For such determinations kelp tion probabilities for ground counts are the error in numbers used to measure harvesting interests should be considered known (Estes and Jameson 1988), but to attainment of management goals (see (VanBlaricom 1984). my knowledge detection probabilities for Bodkin and Ballachey, this issue). I rec- The best opportunity for additional the aerial surveys have not been estimated ommend that research staffs of FWSI study of the sea otter-kelp relationship in for California sea otters. Thus, the total USGS and CDFG undertake the tasks California is at San Nicolas Island (SNI). number of sea otters counted underesti- necessary to resolve these problems, keep- Coastal habitats at SM include a diverse mates the total number present, but the ing in mind the need to determine the array of ecological patch types on shallow magnitude of error is unknown. The relationship of new methods with those rocky substrata, with patches of well- unknown error has not been regarded as a currently in use, such that a long-term developed kelp forests and areas that have si@cant problem because the range of measure of population trend can be rnain- been largely deforested by grazing sea the sea otter population has changed rela- tained without artificial discontinuities. urchins (e.g., Harrold and Reed 1985). tively little since the early 1980s, and The second problem not receiving The FWSAJSGS ecosystem database for surveys have been consistent with regard extensive coverage in this issue involves SNI dates to 1980 and represents system- to technique, timing, weather and sea the relationship of sea otters with the atic monitoring since that time. The fu- conditions, and personnel. biological structure of kelp forest com- ture of the sea otter population at SM is Monitoring of population size and munities in California. Sea otter foraging uncertain given the small number of ani- distribution of sea otters in Californiawill is known to limit numbers of benthic mals present (Benz, Attempts to Reintro- continue to be a crucially important activ- herbivorous invertebrates,particularly sea duce, this issue), but should the population ity, forming the basis for decisions re- urchins, with the result that kelp forests grow and the FWSIUSGS monitoringpro- garding attainment of conservation and are larger, more productive, more diverse gram be continued, many aspects of the

Vol. 13 No, 12 1996 Endangeted Species UPDATE 87 current dispute may be resolved. Because of the potential management significance of data from SNI, continued monitoring of the translocation is imperative.

Problems for the new millennium In this section I offer predictions of three problem areas that may develop over the next few decades as California sea otters emerge from the protection of ESA and reach a consensus OSP level: (1) sustainability of shellfisheries as zonal management of seaotters becomes broadly implemented and accepted, (2) changes in marine oil activity, and the associated consequences for oil spill risk; and (3) the emergence of interest in harvest of sea Photograph by Jefl Foott otters and shellfish by Native Americans. These issues will be direct and logical The chronology of harvest data for lone species only red abalones have sig- consequences of the removal of Califor- California's commercial abalone fisher- nificant populations north of the present nia sea otters from the list of threatened ies suggests that, for a given species, high- sea otter range. Commercial fishing for species, and the attainment of OSP levels. yield areas are fished at arate that typically red abalones has been closed north of San They will be as challenging as any issues exceeds the actual local rate of biomass Francisco since 1945, and recreational currently under consideration. production. Once a given location is fishers are not allowed to use scuba gear, depleted, fishing effort is moved else- as they are in southern California. Stock Sustainability of shelljisheries where. Ultimately the fishery must refo- sizes of red abalones are much larger in CDFG andFWS have for some years cus effort to a less desirable species northern California than elsewhere, prob- endorsed the concept of zonal manage- (because high-yield areas are not able to ably as a direct consequence of reduced ment of California sea otters. Zonal man- recover from depletion before all high- total fishing mortality and the prolonged agement involves restriction of the range yield areas for a given species are de- absence of sea otters (e.g., Pollard 1992). of the seaotter population to certain agreed pleted). This pattern is apparent in harvest However, northern California stocks also areas, with the premise that areas without data records that indicate chronologically face problems. Good recruitments are sea otters will be better suited for produc- progressive depletion of abalone stocks rare and growth rates of post-metamor- tive shellfisheries (see Wendell, this is- (Haliotis spp.) over a period of several phic individuals are low (Tegner 1989; sue). Zonal management likely will decades (Estes and VanBlaricom 1985). Tegner et al. 1992). Large-scale illegal become firmly implementedat some point The problem has been exacerbated by sea harvest is aburgeoning problem, and there after the population is delisted and attains otter predation in central California is interest in opening northern California the OSP level. (Wendell 1994) and disease outbreaks in to commercial harvest. The concept of zonal management southern California (Haaker et al. 1992; Shellfishery management will be includes three assumptions: (1) sea otter Davis 1993; Lafferty and Kuris 1993; further complicated should the Native range can be effectively constrained by an Richards and Davis 1993; VanBlaricom American communitiesof California suc- economically reasonable and politically et al. 1993; Gardner et al. 1995), but the cessfully reassert access to traditional palatable management program; (2) shell- general model of over-utilization seems shellfishing grounds and resources. The fisheries cannot be sustained in the pres- clear for areas and species that have not coastal Native tribes of California relied ence of an unmanaged sea otter population; been affected by sea otters or disease heavily on shellfish gathered from ocean and (3) shellfisheries are sustainable and (Estes and VanBlaricom 1985). shore habitats for subsistence in pre- productive in the absence of sea otters. As a consequence of excessive har- Columbiantimes(e.g., VedderandNonis All three assumptions are controversial vest the present status of southern 1963; Bryan 1970; Douros 1993) and (Estes and VanBlaricom 1985; Wendell California's abalone stocks is dismal. there can be little doubt that any legally et al. 1986; Wendell 1994; see Benz, White abalone are nearly extinct (Davis et binding affirmation of fishing rights for Attempts to Reintroduce; Wendell, this al. 1996) and should be a candidate for coastal California's Native Americans issue). Here I limit my comments to the immediate listing under the ESA. Fisher- would extend to shellfish. Two federal third assumption. I focus primarily on ies for pmk, green, and black abalones court cases, the Boldt Decision and the California's abalone fisheries to illustrate presently are closed because of depleted Rafeedie Decision, both involving issues my arguments, although with some cau- stocks or, in the case of blacks, disease (P. in Washington State, appear to provide tion my views can be generalized to other Haaker, personal communication). legal precedents that could stimulate en- shellfisheries. Among California's harvested aba- try of Native tribes as significant users in

88 Endangered Species UPDATE Vol. 13 No. 12 1996 California shellfisheries. These decisions nomic, cultural, and demographic factors certainly represent a potential pitfall in also stated that it is within the right of that drive global consumer demand for sea otter conservation, and mnal manage- tribal fishers to use modern techniques petroleum products have not changed ap- ment may have a regressive long-term such as scuba diving, to seek newly avail- preciably in recent decades and likely will impact on sea otter conservation if sea able species such as those introduced fiom not change in the foreseeable future, ne- otter population size and range are con- other regions (Katzen 1996), and to pur- cessitating additional development and strained to constant values while oil spill sue commercial as well as subsistence transportation of new oil reserves. risks increase. harvests of shellfish. Removal of California sea otters from The imposition of zonal manage- the list of threatened species, and subse- Harvest by Native Americans ment as the long-term foundation of sea quent attainment of OSP levels, likely The MMPA includes provisions al- otter management carries an assignment will lead to new plans for increased devel- lowing Alaskan Native peoples to harvest of responsibility to fishery management opment of California's marine oil reserves, marine mammals. The provisions are in authority and the shellfishing industry. If and new consequent transportation sce- recognition that harvest of marine marn- sustainable shellfisheries are to be a part narios. Having lost the status of alisted or rnals is a matter of enormous cultural of coastal California's future, shellfishery depleted population, California sea otters sigtllficance to Alaskan Native communi- management may need to assert more also will lose some of their "poster-child ties, and that many marine mammal popu- conservative harvest guidelines, and the clout as the oppressed victims of Big Oil. lations in Alaska are large enough to appearance of Native fishers as signifi- Any pre-OSP negotiated changes in oil sustain Native hunting activity. The origi- cant participants in California shellfish- shipment patterns off California could nal MMPA was ambiguous about meth- eries would require a further reduction in become obsolete as the demand for inex- ods for regulation of Native harvest. the harvest share taken by non-tribal fish- pensive oil supersedes public concern for Subsequent amendments and decisions ers. Ludwig et al. (1993) review the a "recovered"sea otter population. have formalized co-management of ma- discouraging status of the world's marine As development plans are imple- rinemammal stocksbetween federal agen- fisheries, describe several insidious mented, risks of oil spills in sea otter cies and tribal governments. mechanisms that can lead to unforeseen habitat will increase, perhaps precipi- The MMPA provisions for Native and damaging overharvest, and argue for tously. The magnitude of the change is harvest laid groundwork for significant "distrust" of claims of sustainability in difficult to predict for several reasons. take of sea otters by Natives in Alaskan fisheries management. Such patterns cer- First, tanker traffic carrying crude oil south- coastal waters. For most of the 1970s and tainly are of concern for species with the ward from the trans-Alaska pipeline sys- 1980sfew sea otters were taken as various life history characteristics typical of aba- tem (TAPS) has been declining for several legal issues were sorted out. Between lones and many other shemsh species years, and recent changes in TAPS-asso- 1988 and 1996 Native hunters took about harvested in California. The failure to ciated tanker traffic patterns off Califor- 500 sea otters per year from Alaskan sustain shellfisheries will mean a failure nia will reduce spill risks by an unknown coastal waters (C. Gorbics, personalcom- of zonal management, destabilizing a cru- degree (see Jessup et al.; Saunders, this munication). cial element in long-term conservation issue). Second, the choice of offshore The MMPA makes no provision for planning for sea otters. tracts targeted for development will de- harvests of marine mammals by Native pend largely on economic and political peoples outside of Alaska. In 1995, after Changes in marine oil activity factors well beyond the scope of this gray whales were taken off the endan- The California sea otter population discourse. Third, a sigtllficantportion of gered specieslist, theMakahNativepeople has been viewed as vulnerable to the petroleum transport through or near the of coastal Washington State announced effects of spilled oil for at least two de- California sea otter range is done by tank- an interest in a limited harvest of gray cades, on the basis of laboratory studies ers moving refined products between San whales off tribal lands of the Olympic (e.g., Costa and Kooyman 1982; Will- Francisco Bay and Los Angeles County, Peninsula. The tribe cited rights specified iams et al. 1988), examination of surro- and these transport rates are affected by a in 19th century treaties with the U.S. gates for oil spills (VanBlaricom and complex of economic and demographic government including provisions for con- Jameson 1982), oil spill risk modelling factors. Thus, although rates and associ- tinued pursuit of hunting practices in a (e.g., Bonnell et al., this issue), and actual ated spill risks likely will increase over the manner consistent with tribal tradition. oil spills in sea otter habitats. As a conse- long term, the magnitudes of trends in the The Makah people are also known to quence, marine oil development plans rates are dacult to predict. have hunted sea otters in previous gen- routinely have been modiiiedor cancelled Most available risk analyses con- erations, and may be considering an since the listing of the sea otter population sider current scenarios for transportation assertion of treaty-based rights to renew as threatened in 1977. Since the Emon and development. The possibility of a the take of sea otters, whose population Valdez oil spill of 1989, sea otters have significant change of risk levels associ- has been growing rapidly in the vicinity been the very symbol of resistance to ated with removal of sea otters from pro- of tribal lands (R. Jameson, personal marine oil activity for purposes of envi- tected status has not been evaluated communication). ronmental protection (e.g., Batten 1990). quantitatively to my knowledge. Chang- Many Native tribes in the western Nevertheless, the fundamental socioeco- ing oil spill risks after the year 2000 United States signed treaties with the U.S.

Vol. 13 No. 12 1996 Endangered Species UPDATE 89 government in the 19th century. Often Conclusion and settlement of scientificquestions by popu- these agreements involved retention of recommendations lar consensus rather than rigorous elimi- hunting and fishing rights and other tradi- Sea otters are attractive to scientists nation of incomt explanations and the tions in return for land exchanges and because they are accessible, easy to ob- development of accurate syntheses. other concessions. Such agreements of- serve and count, have easily quantifiable If sea otters are to be saved in Califor- ten seem ambiguously worded by con- diets with readily recognized prey, and nia, scientists must do good science and temporary standards. To date, portions of are part of ecological interactions that are avoid advocacy. Advocates must defend the language of five treaties involving interesting, sometimes astonishing, and their interests but not meddle in the dialec- Native tribes in western Washington have always relevant to anumber of significant tic of research. Managers must determine been tested in the U.S. Supreme Court on management issues. It is no coincidence whose data are objectively represented, seven different occasions. Two important that we have a better technical under- and whose models represent good sci- conclusions emerge from Court rulings, standing of many aspects of sea otter ence. The interested public must demand as summarized by Katzen (1996). First, biology than for most other carnivorous the highest standards of all. The reward the right of tribes to fish and hunt in usual marine and terrestrial mammals. It should for commitment to the scientific process and accustomedplacesis an inherent right follow, then, that the available repository and assumption of appropriate roles is the pre-dating the appearance of European of data and models is a powerful resource survival of the California sea otter popu- colonists, and this right remained with for resolution of questions bearing on lation for another millennium. tribes unless explicitly relinquished. Sec- conservation of sea otters in California. In ond, the burden of proof for ambiguity in short, if science can't save the California Acknowledgments treaty language lies with challengers of sea otter population, scienceprobably can't S. K. Carter, G. B. Pauley, and K. K. treaty rights and obligations, not with the save anythmg. VanBlaricom provided helpful comments tribes. The courts interpret treaty lan- Science cannot function as a tool for on the draft manuscript. guage as it is thought to have been under- conservation planning without broad pub- stood by tribes at the time the treaties were lic support. Diminishing support for the Lirature Cited signed (Katzen 1996). scientific method as a pathway for an- Ames, J.A. 1990. Impetus for capturing,cleaning, I suggest the possibility that attain- swers is a widespread and growing prob- and rehabilitating oiled or potentially oiled sea otters after the TNExxon VaMez oil spill. Pages ment of OSP levels by the California sea lem in our culture (e.g., Sagan 1995; 137-141 in K. Bayha and J. Kormendy, editors. otter population may open the door to Ehrlich and Ehrlich 1996). The loss of Sea otter symposium: proceedings of a sympo- proposals for Native harvest in Califor- faith in science results from the consistent sium to evaluate the response effort on behalf of nia. California Native peoples are known failure of society to understand the pro- sea otters after the TNExxon Valdez oil spill into Prince William Sound, Anchorage, Alaska. U.S. to have taken marine mammals, including cess of science, and from the progressive Fish and Wildlife Service, Biological Report sea otters, either for food or to generate replacement of secular logic with tradi- 90(12). 126 pp. pelts for trade (e.g., Kroeber 1925; tional values and mythologies as the basis Batten, B.T. 1990. Press interest in sea otters Bennyhoff 1950; Kroeber and Barrett for making decisions. Here emerges a affectedby theTN Exxon Valdez oil spill: a star is born. Pages 31-40 in K. Bayha and J. 1962; Bleitz 1993). Coastal tribes with- dilemma, wherein public support for sci- Kormendy, editors. Sea otter symposium: Pro- out legally binding forfeitures of hunting ence may be tied to lay participation, but ceedings of a symposium to evaluate the re- rights likely will have a case for the legal lay participation may be at best inappro- sponse effort on behalf of sea otters after the TI development of sea otter harvests. priate, and at worst a detriment to objec- V Exron VaMez oil spill into Prince William Sound, Anchorage, Alaska April 17-19, 1990. It is both difficult and highly pre- tive knowledge. U.S. Fish and Wildlife Service, Biological Re- sumptuous to predict the actions of Native The making of public policy in the port 90(12). 126 pp. tribes with regard to the harvest of sea 1990s is a pluralistic process in which Bennyhoff, J.A. 1950. California fish spears and otters. Given the potential establishment user groups and interest groups sit at a harpoons. University of California Anthropo- logical Record 9:295-337. of a precedent by a non-Alaskan tribe round table with scientists and managers. Bleitz, D.E. 1993. The prehistoric exploitation of such as the Makah, and the stimulus pro- For complex issues involving social, eco- marine mammals and birds at San Nicolas Is- vided by removal of California sea otters nomic, and technical components, plural- land, California. Pages 519-536 in F.G. from protected status, a move toward ism and egalitarianism are appropriate. Hochberg, editor. ThirdCalifornia Islands sym- posium: recent advances in research on the Native hunting of sea otters in California Determination of the OSP level is perhaps California Islands. Santa Barbara Museum of is a reasonable expectation. Such a move a good example. For scientific questions Natural History, Santa Barbara, California. likely would provide politically conten- that underlie many management issues, Bmdy, A.J., K Ralls, and D.B. Siniff. 19%. tious pitfalls and technical challenges for the involvement of interests outside the Potential impacts of oil spills on California sea otters: implicationsoftheEaon VaMezinAlaska. those charged with shepherding the con- realm of science may interfere with the Marine Mammal Science 12:38-53. servation of sea otters after the year 2000. search for truth. In evaluating hypoth- Bryan, B. 1970. Archaeological explorations on Should Native harvest plans materialize eses, scientists cannot be swayed by asso- San Nicolas Island. Southwest Museum Papers, in California, I predict a difficult, high- ciation with advocacy, nor can they mix Number 22. Southwest Museum, Los Angeles, California. 160 pages. profile public debate with no obvious the roles of scientist and advocate, with- Costa, D.P. and G.L. Kooyman. 1982. Oxygen pathway for resolution. out compromising the process. The in- consumption, thennoregulation, and the effect volvement of advocacy may lead to of fur oiling and washing on the seaotter,Enhydra

90 Endangered Species UPDATE Vo1. 13 No. 12 1996 lurris. Canadian Journal of Zoology 60:2761-2767. lone, Halwtis cracherodii, in California. Pages otters to living marine resources in California: a Davis, G.E. 1993. Mysterious demise of southern 214-224 in S. Shepard MJ. Tegner, and S. new mtive. Pages 361-381 in V. Lyle, California black abalone, Halwtis cracherodii Guzmandel Roo,editors. Abalone of the world. editor. Collection of papers prewnted at the Leach, 1814. Journal of Shellfish Research Biology, FisMes, and Culture. Fishing News Ocean Studies Symposium, November 7-11 12:183-184. Books, Blackwell Scientific Publications, Ox- 1982, hilomar, California. California Coastal Davis,G.E.,P.L. Haaker,andD.V. Richards. 1996. ford, United Kingdom. Commission and California Depattment of Fish Status and trends of white abalone at the Califor- Hamold, C. and D.C. Reed. 1985. Food availabil- and Game, Sacramento,California. nia Channel Islands. Transactionsof the Ameri- ity, sea urchin grazing, and kelp forest commu- VanBlariwm, G.R. 1990. Capture of lightly oiled can Ftsheries Society 125:42-48. nity structun. Ecology 66:116@1169. sea otters for nhabilitation: a review of &xi- DeGange, A.R., A.M. Doroff, and D.H. Monson. mn,P. 1996. Panel discussion. Page 2 in S. sions andissues. Pages 130-136 in K. Bayha and 1994. Experimental recovery of sea otter car- Fangman, R. Strickland, and S. Wyllie- J. Konnendy, editors. Sea otter symposium: casses at Kodiak Island, Alaska, following the Echevenia, editors. Rights to shellfish in west- proceedings of a symposium to evaluate the Ewon VaMez oil spill. Marine Mammal Science ern Washington: foots of the tribal claims. New response effort on behaif of sea otters after the TI 10:492-4%. Directions in Marine Affairs 3:l-4. School of V Ezrton Valdez oil spill into Rince William Douros, W.J. 1993. Rehistoric eonon black Marine Affairs, University of Washington, Se- Sound, Anchorage, Alaska April 17-19,1990. abalone by Chumash Indians md sea otters. attle, Washington. U.S. Fish adWildlife Service, Biological Re- Pages 557-566in F.G. Hochberg, editor. Third Kroeber, A.L. 1925. Handbook of the Indians of @ 90(12). 126 PP. California Islands symposium: recent advances California.Bureau of American Ethnology, Bul- VanBlaricom, G.R. andR.J. Jameson. 1982. Lum- in research on the California Islands. Sam letin 78. Washington, D.C. 995 pages. berspillinCaliforniawaters: implicationsforoil Barbara Museum of Natural History, Santa Bar- Kroeber, A.L., and S.A. Barrett. 1962. Fishing spills and sea otters. Science 215:1503-1505. bara, California. among the Indians of northwestern California. VanBlariwm, G.R. andT.A. Gomall. 1989. Miti- Duggins, D.O. 1988. The effects of kelp forests on University of California Anthropological Record gation of risks of oil spills for marine wildlife: near-shoreenvironments: biomass, detritus, and 21: 1-210. avoiding another hnV&z disaster. Plenary altemlflow. Pages 192-201inGRVanBlaricom Lafferty, K. and A. Kwis. 1993. Mass modality of presentation, Eighth Biennial Conference on the and J.A. Ektes, editors. The community ecology abalone Haliotis cracherodii on the California Biology of Marine Mammals, Society for Ma- of sea otters. Ecological Studies, Vol. 65. Channel Islands: tests of epidemiological hy- rine Mammalogy, Pacitic Grove, California Springer-Verlag, Heidelberg, Germany. potheses. Marine Ecology Progress Series VanBlaricom, G.R., J.L. Ruediger, C. Friedman, Duggins, D.O., S.A. Simenstad, and J.A. Estes. %:239-248. D.D. Woodard, and R.P. Hedrick. 1993. Dis- 1989. Mamcation of secondary production by Loughb, T.R., editor. 1994. Marine mammals covery of withering syndrome amongblackaba- kelp detritus in coastal marine ecosystems. Sci- and the Exxon Valdez. Academic Ress, Or- lone Haliotis cracherodii Leach, 1814 ence 245170-173. lando, Florida. populations at San Nicolas Island, California. Ehrlich, P.R. and A.H. Ehrlich. 1996. Betrayal of Ludwig, D., R. Hilborn, and C. Walters. 1993. Journal of Shellfish Research 12185-188. science and reason. Island Press, Washington, Uncertainty, resource exploitation, and conser- Vedder, J.G. and R.M. Norris. 1%3. Geology of D.C. 352 pages. vation: lessons fromhistory. Science 260: 17,36. San Nicolas Island California. Geological Sur- Estes, J.A. 1991. Catastrophes and conservation: McLean, J.H. 1%2. Sublittoral ecology of kelp vey Professional Paper 369. U.S. Geological lessons from sea otters and the Exron Valdez. beds of the opencoast area near Carmel, Califor- Survey, Washington, D.C. 65 pp. Science 254:15%. nia. Biological Bulletin 12295-114. Wendell, F.E. 1994. Relationship between sea Estes, J.A. and D.O. Duggins. 1995. Sea otters and Pollard, S. 1992. Red abalone, Halwtis ncfescens; otter range expansion and red abalone abun- kelp forests in Alaska generality and variation Relative impacts of dondfisheries and sea dance and size distribution in central California. in a community ecological paradigm. Ecologi- otterpredationontheabundance,size frequency, Califomia Fish and Game W45-56. cal Monographs 6575-100. and microhabitat distribution of red abalone Wendell, F.E., R.A. Hardy, J.A. Ames, and R.T. Estes, J.A. and R.J. Jameson. 1988. A double- populations in central and northern California. Burge. 1986. Temporal and spatial patterns in survey estimate for sighting @ability of sea M.S. thesis, University of California, SantaCruz, sea otter (Enhydra lutris)range expansion and in otters in Califomia. Journal of WildlifeManage- California. the loss of the Pismo clam fisheries. California ment 52:70-76. Richads, D.V. and G.E. Davis. 1993. Early Fish and Game 72197-212. Estes, J.A. and G.R. VanBlaricom. 1985. Sea- warnings of modern population collapse in black Williams, T.M., R.A. Kastelein, R.W. Davis, and otters and shellfisheries. Pages 187-235in J.R. abalone, Haliotis cracherodiiLeach, 1814 at the J.A. Thomas. 1988. The effects of oil contami- Beddington,RJ.H.Beverton,andD.M. Lavigne, California Channel Islands. Joumal of Shellfish nation andcleaningon seaotters (Enhydralutris). editors. Marinemammalsand fisheries. George, Research 12:189-194. I. Themmegulatory implications based on pelt Allen, and Unwin, London, United Kingdom. Sagan, C. 1995. The demon-haunted world: sci- studies. Canadian Journal of Zoology 662776- Foster, M.S. and D.R. Schiel. 1988. Kelp cornmu- ence as a candle in the dark. Random House, 2781. nities and sea otters: keystone species or just New York, New York. 457 pp. another brick in the wall? Pages 92-115 in G.R. Tarpley, J.D. and D. Glantz. 1992. Giant kelp. VanBlaricom and J.A. Estes, editors. The com- Pages 2-5 in W.S. Leet, C.M. Dewees, and C.W. munity ecology of sea otters. Ecological Stud- Haugen, editors. California's living marine re- ies, Vol. 65. Springer-Verlag, Heidelberg, sources and their utilization. California Sea .Germany. Grant, Davis, California Gardner, G.R., J.C. Hmhbarger, J.L. Lake, T.K. Tegner, M.J. 1989. The Californiaabalonefishe~y: Sawyer, K.L. Price, M.D. Stephenson, P.L. production, ecological interactions, and pros- Haaker, mdH.A. Togstad. 1995.Association of pects for the future. Pages 401-420in J. Caddy, prokaryotes with symptomatic appearance of editor. Marine invertebrate fisheries; their as- withering syndrome in black abalone Haliotis sessment and management. John Wiey and cracherodii. Journal of Invertebrate Pathology Sons, New York, New York. 66:lll-120. Tegner, M.J., J. DeMartini, and K. Karpov. 1992. Garrott, R.A., L.L. Ebehadt, and D.M. Bum. The California red abalone fishery: a case study 1993. Mortality of sea otters in Prince William in complexity. Pages 370-383 in S. Shepard, Glenn R. VanBlaricom is with the Washington Sound following the Ewon VaMez oil spill. M.J. Tegner, and S. Guzman del Roo, editors. Cooperative Fish and Wildlife Research Unit of Marine Mammal Science 9:343-359. Abalone of the world: biology, fisheries, and the Biological Resources Division, U.S. Haaker, P.L., D.V. Richards, C. Friedman, G.E. culture. Fishing News Books, Blackwell Scien- Geological Swey. He can be reached at School Davis,D. Parker, andH.A. Togstad. 1992. Mass tific Publications, Oxford, United Kingdom. of Fisheries, Box 357980, University of mortality and withering syndrome in black aba- VanBlaricom, G.R. 1984. Relationships of sea Washington, Seattle, Washington 98195.

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