DOCSLIB.ORG

CALIFORNIA SEA LIONS: an INDICATOR for INTEGRATED ECOSYSTEM ASSESSMENT Calcofi Rep., Vol

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
CALIFORNIA SEA LIONS: an INDICATOR for INTEGRATED ECOSYSTEM ASSESSMENT Calcofi Rep., Vol MELIN ET AL.: CALIFORNIA SEA LIONS: AN INDICATOR FOR INTEGRATED ECOSYSTEM ASSESSMENT CalCOFI Rep., Vol. 53, 2012 CALIFORNIA SEA LIONS: AN INDICATOR FOR INTEGRATED ECOSYSTEM ASSESSMENT OF THE CALIFORNIA CURRENT SYSTEM SHARON R. MELIN, ANTHONY J. ORR, JEFFREY D. HARRIS, JEFFREY L. LAAKE, AND ROBERT L. DELONG National Oceanic and Atmospheric Administration National Marine Fisheries Service Alaska Fisheries Science Center National Marine Mammal Laboratory Seattle, WA 98115 ABSTRACT periods of large- and small-scale environmental changes, We examined the annual number of pups born, pup be sensitive to changes in the ecosystem, and have traits mortality, and pup weights of California sea lions (Zalo- that respond to and that can be measured in relation to phus californianus) at San Miguel Island, California, and the ecosystem processes of interest (Rice and Rochet related them to large and small-scale oceanographic 2005). Upper trophic level marine predators often make indices in the central California Current System (CCS) good indicator species because annual changes in popu- between 1997 and 2011. Annual variability in the num- lation parameters, such as births, mortality, and growth, ber of pups born and pup mortality was best explained are often linked to oceanographic changes (e.g., pro- by the mutlitvariate ENSO index (MEI) that tracks the duction of chlorophyll and zooplankton) that affect the El Niño/La Niña cycle. Annual variability in average pup distribution and availability of lower trophic level prey weights was best explained by a sea surface temperature (e.g., euphausiids, fishes, cephalopods) (Ainley et al. 2005; anomaly index (SSTA); average pup weights were lower Beauplet et al. 2005; Foracada et al. 2005; Reid and For- in years when the SSTA was greater than 1˚C above cada 2005; Reid et al. 2005; Wells et al. 2008). normal. We demonstrated that California sea lions are California sea lions (Zalophus californianus) are upper sensitive to large and small-scale changes in ocean condi- trophic level marine predators that are abundant and tions through changes in their reproductive success, pup permanent residents of the CCS. Their range extends growth, and pup mortality. Therefore, California sea lions from northern Mexico to Canada and much of their are an ideal indicator species for the IEA of the CCS. life history has evolved to take advantage of the high ocean productivity in the CCS. Weaning and reproduc- INTRODUCTION tion occur during late spring and early summer, respec- Integrated ecosystem assessment (IEA) is the scien- tively, during the peak upwelling period in the CCS tific foundation that supports ecosystem-based manage- when primary productivity is at its maximum (Bograd et ment (Levin et al. 2009). A central component of IEA al. 2009). California sea lion females give birth to a single is the identification of indicator species that respond pup between May and June that they provision through to changes in the ecosystem. In the California Cur- lactation. Lactation usually lasts 11 months during which rent System (CCS), large-scale global processes like the time females are central-place foragers, alternating 2–5 Pacific Decadal Oscillation (PDO), North Pacific Gyre day foraging trips to sea with 1–2 day nursing visits to Oscillation (NPGO), and El Niño Southern Oscillation the colony (Melin et al. 2000). Lactating females exploit (ENSO) as well as small-scale processes like localized the continental shelf, slope, and offshore regions of the disruption of seasonal upwelling can alter the trophic central and southern CCS throughout the year (Kuhn dynamics on time scales of months, years, or decades 2006; Melin et al. 2008), making more than 60 foraging (Hayward 1997; McGowan et al. 2003; Goericke et al. trips between the California Channel Islands and Mon- 2007; Bjorkstedt et al. 2010; King et al. 2011). In the terey Bay, California. Their large foraging area and diving CCS, the atmospheric forcing associated with the PDO capabilities give them access to a diverse prey assemblage and NPGO controls decadal patterns in upwelling and resulting in a diet that includes over 30 taxa of fish and results in regionally variable coastal upwelling condi- cephalopods (Antonelis et al. 1990; Lowry et al. 1990; tions that affect primary and secondary marine produc- Melin et al. 2010). tivity and consequently, the distribution of fishes and Over the past 40 years, population parameters of Cali- other higher trophic level marine organisms. Thus, suit- fornia sea lions have shown annual variability associated able indicator species for the CCS must be sensitive to with large- and small-scale oceanographic events. The marine ecosystem changes at various spatial and tempo- populations breeding in the California Channel Islands ral scales. An indicator species should be directly observ- off the southern coast of California experienced signif- able, have a historical time series of data that includes icant declines in births, increased pup mortality, lower 140 MELIN r3 lo.indd 140 10/30/12 9:06 PM MELIN ET AL.: CALIFORNIA SEA LIONS: AN INDICATOR FOR INTEGRATED ECOSYSTEM ASSESSMENT CalCOFI Rep., Vol. 53, 2012 mean pup weights, and changes in the diet in response METHODS to the warm oceanographic conditions associated with the El Niño phase of ENSO events in 1982–83 (DeLong Oceanographic Indices et al. 1991), 1992–93 (DeLong and Melin 2000), and PDO, NPGO, and ENSO. The PDO signal is 1997–98 (Weise and Harvey 2008; Melin et al. 2010). strongest north of 38˚N, the NPGO is strongest south The population effects lasted for 1 to 4 years (Lowry of 38˚N (Di Lorenzo et al. 2008), and the ENSO sig- and Maravilla-Chavez 2005). Furthermore, Califor- nal varies depending on the strength of the event at the nia sea lions are also sensitive to regional and localized equator (King et al. 2011) but all three indices are related changes in their foraging environment that affect their and affect the CCS (King et al. 2011). So, we explored prey base (Weise et al. 2006; Weise and Harvey 2008). In relationships between these indices and California sea 2009, a brief collapse of the summer seasonal upwelling lion population parameters. For each year between along the central California coast (Bjorkstedt et al. 2010) 1997 and 2011, monthly values for the PDO (http:// resulted in an unprecedented level of California sea lion jisao.washington.edu/pdo/PDO.latest), NPGO (http:// pup mortality, a dramatic change in the adult female diet, www.o3d.org/npgo/npgo.php), and ENSO (multivar- and contributed to a reduction in the number of births iate ENSO index (MEI), http://www.esrl.noaa.gov/ in the following year (Melin et al. 2010). The impact of psd/enso/mei/table.html) were averaged for: 1) October these anomalous oceanographic events on the California through the following June (average gestation period) for sea lion population are presumably meditated through models explaining trends in pup births, 2) June and July their affect on sea lion prey availability (i.e., distribution, for models evaluating pup mortality up to 5 weeks of abundance), but it is difficult to measure prey availabil- age, and 3) June through September for models explor- ity directly. Therefore indices of ocean conditions like ing variability in pup mortality and pup weights at 14 the PDO, NPGO, upwelling, and sea surface tempera- weeks of age. Because the MEI is measured at the equa- tures that affect distribution and abundance of prey can tor, the index was lagged 3 months, after testing lags of be used as proxies for prey availability to California sea 0 to 6 months, based on the highest positive correlation lions and consequently, may explain annual variability in between the average MEI values and local sea surface California sea lion population indices. temperatures in lactating female sea lion foraging areas A reduction in prey available to lactating California in the CCS (e.g., MEI value at the equator in January sea lion females has the greatest population effect because was assigned the CCS MEI value in April). it affects reproduction and survival of pups. When prey is Local Upwelling and Sea Surface Temperature. Large- scarce, lactating females expend more energy to meet the scale oceanographic patterns affect local ocean con- demands of reproduction by foraging farther from the ditions in the CCS through changes in the timing, colony and/or diving deeper presumably in response to strength, and characteristics of upwelling and changes changes in the spatial distribution of their prey (Melin et in sea surface temperature that affect the distribution of al. 2008). More importantly, movement of prey outside sea lion prey over shorter time periods (i.e., weeks or the normal adult female foraging range results in lon- months) and may have more immediate effects on Cali- ger foraging trips (Melin et al. 2008),which may result fornia sea lion population indices than large-scale pro- in slower growth or starvation of the pup if the for- cesses. We used upwelling and sea surface temperature aging trip durations exceed the pup’s fasting capability. indices to investigate the effect of small-scale ocean- In addition, because lactating females are usually also ographic conditions on California sea lion population pregnant during nine months of the 11-month lacta- and diet indices. The monthly coastal upwelling index tion period, a diet that is insufficient to support both at 33˚N 119˚W (UWI33) and 36˚N 122˚W (UWI36) lactation and gestation may result in the resorption of (http://www.pfeg.noaa.gov/products/PFEL/modeled/ the fetus or a premature birth. Given the relationships indices/upwelling/NA/data_download.html) between between ocean conditions, prey availability, and Califor- 1997 and 2011 was used as an index of regional monthly nia sea lion behavior, we used regional and local ocean- ocean productivity along the central California coast ographic and adult female diet indices as explanatory (Schwing et al.
Load more

Recommended publications
  • Marine Ecology Progress Series 477:177
    Vol. 477: 177–188, 2013 MARINE ECOLOGY PROGRESS SERIES Published March 12 doi: 10.3354/meps10144 Mar Ecol Prog Ser Larval exposure to shared oceanography does not cause spatially correlated recruitment in kelp forest fishes Jenna M. Krug*, Mark A. Steele Department of Biology, California State University, 18111 Nordhoff St., Northridge, California 91330-8303, USA ABSTRACT: In organisms that have a life history phase whose dispersal is influenced by abiotic forcing, if individuals of different species are simultaneously exposed to the same forcing, spa- tially correlated settlement patterns may result. Such correlated recruitment patterns may affect population and community dynamics. The extent to which settlement or recruitment is spatially correlated among species, however, is not well known. We evaluated this phenomenon among 8 common kelp forest fishes at 8 large reefs spread over 30 km of the coast of Santa Catalina Island, California. In addition to testing for correlated recruitment, we also evaluated the influences of predation and habitat quality on spatial patterns of recruitment. Fish and habitat attributes were surveyed along transects 7 times during 2008. Using these repeated surveys, we also estimated the mortality rate of the prey species that settled most consistently (Oxyjulis californica) and evaluated if mortality was related to recruit density, predator density, or habitat attributes. Spatial patterns of recruitment of the 8 study species were seldom correlated. Recruitment of all species was related to one or more attributes of the habitat, with giant kelp abundance being the most widespread predictor of recruitment. Mortality of O. californica recruits was density-dependent and declined with increasing canopy cover of giant kelp, but was unrelated to predator density.
    [Show full text]
  • MINNESOTA MUSTELIDS Young
    By Blane Klemek MINNESOTA MUSTELIDS Young Naturalists the Slinky,Stinky Weasel family ave you ever heard anyone call somebody a weasel? If you have, then you might think Hthat being called a weasel is bad. But weasels are good hunters, and they are cunning, curious, strong, and fierce. Weasels and their relatives are mammals. They belong to the order Carnivora (meat eaters) and the family Mustelidae, also known as the weasel family or mustelids. Mustela means weasel in Latin. With 65 species, mustelids are the largest family of carnivores in the world. Eight mustelid species currently make their homes in Minnesota: short-tailed weasel, long-tailed weasel, least weasel, mink, American marten, OTTERS BY DANIEL J. COX fisher, river otter, and American badger. Minnesota Conservation Volunteer May–June 2003 n e MARY CLAY, DEMBINSKY t PHOTO ASSOCIATES r mammals a WEASELS flexible m Here are two TOM AND PAT LEESON specialized mustelid feet. b One is for climb- ou can recognize a ing and the other for hort-tailed weasels (Mustela erminea), long- The long-tailed weasel d most mustelids g digging. Can you tell tailed weasels (M. frenata), and least weasels eats the most varied e food of all weasels. It by their tubelike r which is which? (M. nivalis) live throughout Minnesota. In also lives in the widest Ybodies and their short Stheir northern range, including Minnesota, weasels variety of habitats and legs. Some, such as badgers, hunting. Otters and minks turn white in winter. In autumn, white hairs begin climates across North are heavy and chunky. Some, are excellent swimmers that hunt to replace their brown summer coat.
    [Show full text]
  • Food Habits of Black Bears in Suburban Versus Rural Alabama
    Food Habits of Black Bears in Suburban versus Rural Alabama Laura Garland, Auburn University, School of Forestry and Wildlife Sciences, Auburn, AL 36849 Connor Ellis, 18832 #1 Gulf Boulevard Indian Shores, FL 33785 Todd Steury, Auburn University, School of Forestry and Wildlife Sciences, Auburn, AL 36849 Abstract: Little is known about the food habits of black bears (Ursus americanus) in Alabama. A major concern is the amount of human influence in the diet of these bears as human and bear populations continue to expand in a finite landscape and bear-human interactions are increasing. To better understand dietary habits of bears, 135 scats were collected during late August to late November 2011–2014. Food items were classified into the cat- egories of fruit, nuts/seeds, insects, anthropogenic, animal hairs, fawn bones, and other. Plant items were classified down to the lowest possible taxon via visual and DNA analysis as this category composed the majority of scat volumes. Frequency of occurrence was calculated for each food item. The most commonly occurring foods included: Nyssa spp. (black gum, 25.2%), Poaceae family (grass, 24.5%), Quercus spp. (acorn, 22.4%), and Vitis spp. (muscadine grape, 8.4%). Despite the proximity of these bear populations to suburban locations, during our sampling period we found that their diet primarily comprised vegetation, not anthropogenic food; while 100% of scat samples contained vegetation, only 19.6% of scat samples contained corn and no other anthropogenic food sources were detected. Based on a Fisher’s exact test, dietary composition did not differ between bears living in subur- ban areas compared to bears occupying more rural areas (P = 0.3891).
    [Show full text]
  • CHECKLIST and BIOGEOGRAPHY of FISHES from GUADALUPE ISLAND, WESTERN MEXICO Héctor Reyes-Bonilla, Arturo Ayala-Bocos, Luis E
    ReyeS-BONIllA eT Al: CheCklIST AND BIOgeOgRAphy Of fISheS fROm gUADAlUpe ISlAND CalCOfI Rep., Vol. 51, 2010 CHECKLIST AND BIOGEOGRAPHY OF FISHES FROM GUADALUPE ISLAND, WESTERN MEXICO Héctor REyES-BONILLA, Arturo AyALA-BOCOS, LUIS E. Calderon-AGUILERA SAúL GONzáLEz-Romero, ISRAEL SáNCHEz-ALCántara Centro de Investigación Científica y de Educación Superior de Ensenada AND MARIANA Walther MENDOzA Carretera Tijuana - Ensenada # 3918, zona Playitas, C.P. 22860 Universidad Autónoma de Baja California Sur Ensenada, B.C., México Departamento de Biología Marina Tel: +52 646 1750500, ext. 25257; Fax: +52 646 Apartado postal 19-B, CP 23080 [email protected] La Paz, B.C.S., México. Tel: (612) 123-8800, ext. 4160; Fax: (612) 123-8819 NADIA C. Olivares-BAñUELOS [email protected] Reserva de la Biosfera Isla Guadalupe Comisión Nacional de áreas Naturales Protegidas yULIANA R. BEDOLLA-GUzMáN AND Avenida del Puerto 375, local 30 Arturo RAMíREz-VALDEz Fraccionamiento Playas de Ensenada, C.P. 22880 Universidad Autónoma de Baja California Ensenada, B.C., México Facultad de Ciencias Marinas, Instituto de Investigaciones Oceanológicas Universidad Autónoma de Baja California, Carr. Tijuana-Ensenada km. 107, Apartado postal 453, C.P. 22890 Ensenada, B.C., México ABSTRACT recognized the biological and ecological significance of Guadalupe Island, off Baja California, México, is Guadalupe Island, and declared it a Biosphere Reserve an important fishing area which also harbors high (SEMARNAT 2005). marine biodiversity. Based on field data, literature Guadalupe Island is isolated, far away from the main- reviews, and scientific collection records, we pres- land and has limited logistic facilities to conduct scien- ent a comprehensive checklist of the local fish fauna, tific studies.
    [Show full text]
  • FISHER Pekania Pennanti
    WILDLIFE IN CONNECTICUT WILDLIFE FACT SHEET FISHER Pekania pennanti Background J. FUSCO © PAUL In the nineteenth century, fishers became scarce due to forest logging, clearing for agriculture, and overexploitation. By the 1900s, fishers were considered extirpated from the state. Reforestation and changes in land-use practices have restored the suitability of the fisher’s habitat in part of its historic range, allowing a population to recolonize the northeastern section of the state. Fishers did not recolonize suitable habitat in northwestern Connecticut, since the region was isolated from a source population. Fishers were rare in western Massachusetts, and the developed and agricultural habitats of the Connecticut River Valley were a barrier to westward expansion by fishers in northeastern Connecticut. A project to reintroduce this native mammal into northwestern Connecticut was initiated by the Wildlife Division in 1988. Funds from reimbursement of trapping wild turkeys in Connecticut for release in Maine were used to purchase fishers caught by cooperating trappers in New Hampshire and Vermont. In what is termed a "soft release," fishers were penned and fed at the release site for a couple of weeks prior to being released. Through radio and snow tracking, biologists later found that the fishers that were released in northwestern Connecticut had high survival rates and successfully reproduced. As a result of this project, a viable, self-sustaining population of this native mammal is now established in western Connecticut. Fishers found throughout eastern Connecticut are a result of natural range expansion. In 2005, Connecticut instituted its first modern day regulated trapping season for fishers. Most northern states have regulated fisher trapping seasons.
    [Show full text]
  • 2021 Fur Harvester Digest 3 SEASON DATES and BAG LIMITS
    2021 Michigan Fur Harvester Digest RAP (Report All Poaching): Call or Text (800) 292-7800 Michigan.gov/Trapping Table of Contents Furbearer Management ...................................................................3 Season Dates and Bag Limits ..........................................................4 License Types and Fees ....................................................................6 License Types and Fees by Age .......................................................6 Purchasing a License .......................................................................6 Apprentice & Youth Hunting .............................................................9 Fur Harvester License .....................................................................10 Kill Tags, Registration, and Incidental Catch .................................11 When and Where to Hunt/Trap ...................................................... 14 Hunting Hours and Zone Boundaries .............................................14 Hunting and Trapping on Public Land ............................................18 Safety Zones, Right-of-Ways, Waterways .......................................20 Hunting and Trapping on Private Land ...........................................20 Equipment and Fur Harvester Rules ............................................. 21 Use of Bait When Hunting and Trapping ........................................21 Hunting with Dogs ...........................................................................21 Equipment Regulations ...................................................................22
    [Show full text]
  • Environmental DNA Reveals the Fine-Grained and Hierarchical
    www.nature.com/scientificreports OPEN Environmental DNA reveals the fne‑grained and hierarchical spatial structure of kelp forest fsh communities Thomas Lamy 1,2*, Kathleen J. Pitz 3, Francisco P. Chavez3, Christie E. Yorke1 & Robert J. Miller1 Biodiversity is changing at an accelerating rate at both local and regional scales. Beta diversity, which quantifes species turnover between these two scales, is emerging as a key driver of ecosystem function that can inform spatial conservation. Yet measuring biodiversity remains a major challenge, especially in aquatic ecosystems. Decoding environmental DNA (eDNA) left behind by organisms ofers the possibility of detecting species sans direct observation, a Rosetta Stone for biodiversity. While eDNA has proven useful to illuminate diversity in aquatic ecosystems, its utility for measuring beta diversity over spatial scales small enough to be relevant to conservation purposes is poorly known. Here we tested how eDNA performs relative to underwater visual census (UVC) to evaluate beta diversity of marine communities. We paired UVC with 12S eDNA metabarcoding and used a spatially structured hierarchical sampling design to assess key spatial metrics of fsh communities on temperate rocky reefs in southern California. eDNA provided a more‑detailed picture of the main sources of spatial variation in both taxonomic richness and community turnover, which primarily arose due to strong species fltering within and among rocky reefs. As expected, eDNA detected more taxa at the regional scale (69 vs. 38) which accumulated quickly with space and plateaued at only ~ 11 samples. Conversely, the discovery rate of new taxa was slower with no sign of saturation for UVC.
    [Show full text]
  • Estimating Sustainable Bycatch Rates for California Sea Lion Populations in the Gulf of California
    Contributed Paper Estimating Sustainable Bycatch Rates for California Sea Lion Populations in the Gulf of California JARED G. UNDERWOOD,∗‡ CLAUDIA J. HERNANDEZ CAMACHO,∗† DAVID AURIOLES-GAMBOA,† AND LEAH R. GERBER∗ ∗Ecology, Evolution and Environmental Science, School of Life Sciences, Arizona State University, College & University Drive, Tempe, AZ 85287-1501, U.S.A. †Centro Interdisciplinario de Ciencias Marinas-IPN, Av. IPN s/n Col. Playa Palo de Santa Rita, La Paz BCS 23096, Mexico´ Abstract: Commercial and subsistence fisheries pressure is increasing in the Gulf of California, Mexico. One consequence often associated with high levels of fishing pressure is an increase in bycatch of marine mammals and birds. Fisheries bycatch has contributed to declines in several pinniped species and may be affecting the California sea lion (Zalophus californianus) population in the Gulf of California. We used data on fisheries and sea lion entanglement in gill nets to estimate current fishing pressure and fishing rates under which viable sea lion populations could be sustained at 11 breeding sites in the Gulf of California. We used 3 models to estimate sustainable bycatch rates: a simple population-growth model, a demographic model, and an estimate of the potential biological removal. All models were based on life history and census data collected for sea lions in the Gulf of California. We estimated the current level of fishing pressure and the acceptable level of fishing required to maintain viable sea lion populations as the number of fishing days (1 fisher/boat setting and retrieving 1 day’s worth of nets) per year. Estimates of current fishing pressure ranged from 101 (0–405) fishing days around the Los Machos breeding site to 1887 (842–3140) around the Los Islotes rookery.
    [Show full text]
  • How to Avoid Incidental Take of American Marten
    How to Avoid Incidental Take Of American Marten While Trapping or Snaring Mink and other Furbearers. Jon Stone The purpose of this information is to reduce injury and mortality to the Endangered American Marten population caused by trapping mink and/or other furbearers. Marten are similar in appearance and habits to mink, and their ranges overlap with other furbearer species, and with each other. Therefore, it is important for trappers to know how to distinguish marten from mink, to recognize their preferred habitat types, and to avoid capturing or harvesting marten. Trappers must also learn what to do if a marten is caught incidentally. American marten Current Status Researchers speculate the current American marten (Martes americana) population on Cape Breton Island may be less than 50 animals. Consequently, in the summer of 2001, the marten population on Cape Breton Island was provincially listed as "endangered" under the Nova Scotia Endangered Species Act. Thought to be extirpated from the mainland, several marten re-introductions have been attempted. It seems these reintroductions have been successful, as there have been some very recent records of marten in southwest Nova Scotia. The status of the marten on the mainland is considered "data deficient," (meaning more research is required before giving it a designation). The harvesting of marten is not permitted in Nova Scotia. Time is of the Essence Small, localized populations, like the marten on Cape Breton Island, are vulnerable to local extinction. Factors such as inbreeding (a genetic effect), as well as habitat loss, accidental capture, starvation, and certain random events like disease, fire, and unusual weather events could eliminate the entire population.
    [Show full text]
  • Vii Fishery-At-A-Glance: California Sheephead
    Fishery-at-a-Glance: California Sheephead (Sheephead) Scientific Name: Semicossyphus pulcher Range: Sheephead range from the Gulf of California to Monterey Bay, California, although they are uncommon north of Point Conception. Habitat: Both adult and juvenile Sheephead primarily reside in kelp forest and rocky reef habitats. Size (length and weight): Male Sheephead can grow up to a length of three feet (91 centimeters) and weigh over 36 pounds (16 kilograms). Life span: The oldest Sheephead ever reported was a male at 53 years. Reproduction: As protogynous hermaphrodites, all Sheephead begin life as females, and older, larger females can develop into males. They are batch spawners, releasing eggs and sperm into the water column multiple times during their spawning season from July to September. Prey: Sheephead are generalist carnivores whose diet shifts throughout their growth. Juveniles primarily consume small invertebrates like tube-dwelling polychaetes, bryozoans and brittle stars, and adults shift to consuming larger mobile invertebrates like sea urchins. Predators: Predators of adult Sheephead include Giant Sea Bass, Soupfin Sharks and California Sea Lions. Fishery: Sheephead support both a popular recreational and a commercial fishery in southern California. Area fished: Sheephead are fished primarily south of Point Conception (Santa Barbara County) in nearshore waters around the offshore islands and along the mainland shore over rocky reefs and in kelp forests. Fishing season: Recreational anglers can fish for Sheephead from March 1through December 31 onboard boats south of Point Conception and May 1 through December 31 between Pigeon Point and Point Conception. Recreational divers and shore-based anglers can fish for Sheephead year round.
    [Show full text]
  • The Scientific Basis for Conserving Forest Carnivores: American Marten, Fisher, Lynx and Wolverine in the Western United States
    United States The Scientific Basis for Conserving Forest Carnivores Department of Agriculture Forest Service American Marten, Fisher, Lynx, Rocky Mountain and Wolverine Forest and Range Experiment Station in the Western United States Fort Collins, Colorado 80526 General Technical Report RM-254 Abstract Ruggiero, Leonard F.; Aubry, Keith B.; Buskirk, Steven W.; Lyon, L. Jack; Zielinski, William J., tech. eds. 1994. The Scientific Basis for Conserving Forest Carnivores: American Marten, Fisher, Lynx and Wolverine in the Western United States. Gen. Tech. Rep. RM-254. Ft. Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 184 p. This cooperative effort by USDA Forest Service Research and the National Forest System assesses the state of knowledge related to the conservation status of four forest carnivores in the western United States: American marten, fisher, lynx, and wolverine. The conservation assessment reviews the biology and ecology of these species. It also discusses management considerations stemming from what is known and identifies information needed. Overall, we found huge knowledge gaps that make it difficult to evaluate the species’ conservation status. In the western United States, the forest carnivores in this assessment are limited to boreal forest ecosystems. These forests are characterized by extensive landscapes with a component of structurally complex, mesic coniferous stands that are characteristic of late stages of forest development. The center of the distrbution of this forest type, and of forest carnivores, is the vast boreal forest of Canada and Alaska. In the western conterminous 48 states, the distribution of boreal forest is less continuous and more isolated so that forest carnivores and their habitats are more fragmented at the southern limits of their ranges.
    [Show full text]
  • 2019 Annual Marine Environmental Analysis and Interpretation Report
    2019 ANNUAL MARINE ENVIRONMENTAL ANALYSIS AND INTERPRETATION San Onofre Nuclear Generating Station ANNUAL MARINE ENVIRONMENTAL ANALYSIS AND INTERPRETATION San Onofre Nuclear Generating Station July 2020 Page intentionally blank Report Preparation/Data Collection – Oceanography and Marine Biology MBC Aquatic Sciences 3000 Red Hill Avenue Costa Mesa, CA 92626 Page intentionally blank TABLE OF CONTENTS LIST OF FIGURES ........................................................................................................................... iii LIST OF TABLES ...............................................................................................................................v LIST OF APPENDICES ................................................................................................................... vi EXECUTIVE SUMMARY .............................................................................................................. vii CHAPTER 1 STUDY INTRODUCTION AND GENERATING STATION DESCRIPTION 1-1 INTRODUCTION ................................................................................................................... 1-1 PURPOSE OF SAMPLING ......................................................................................... 1-1 REPORT APPROACH AND ORGANIZATION ........................................................ 1-1 DESCRIPTION OF THE STUDY AREA ................................................................... 1-1 HISTORICAL BACKGROUND ...........................................................................................
    [Show full text]