ALASKA HARBOR SEAL (Phoca vitulina) CONTAMINANTS A Review with Annotated Bibliography Rebecca S. Papa Paul R. Becker U.S. DEPARTMENT OF COMMERCE National Institute of Standards and Technology NIST Charleston Laboratory Charleston, SC 29412 U.S. DEPARTMENT OF COMMERCE Technology Administration National Institute of Standards and Technology Gaithersburg, MD 20899-0001 QC TOO .U56 NO. 6211 1998 ALASKA HARBOR SEAL {Phoca vitulina) CONTAMINANTS A Review with Annotated Bibliography Rebecca S. Papa Paul R. Becker National Institute of Standards and Technology NIST Charleston Laboratory 219 Fort Johnson Road Charleston, SC 29412 October 1998 U.S. DEPARTMENT OF COMMERCE William M. Daley, Secretary TECHNOLOGY ADMINISTRATION Gary Bachula, Acting Under Secretary for Technology NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY Raymond G. Kammer, Director CONTENTS page Tables iv Figures iv Preface v A cknowledgem ents vi Disclaimer vi SECTION I: CONTAMINANTS IN ALASKA HARBOR SEALS: A SUMMARY OF THE AVAILABLE DATA 1 Background 2 Heavy Metals 4 Persistent Organic Pollutants 11 Contaminant Levels and Health Effects : 30 Conclusions and Recomendations 33 SECTION II: DATA TABLES 37 Table 2. 1 . Mean Concentrations of Metals and Metalloids in Harbor Seals, Phoca vitulina, from Alaska 38 Table 2.2. Mean Concentrations of Metals and Metalloids in Harbor Seals, Phoca vitulina, from the U.S. Outside of Alaska 39 Table 2.3. Mean Concentrations of Metals and Metalloids in Harbor Seals, Phoca vitulina, from Regions Outside of the U.S 41 Table 2.4. Mean Concentrations of Persistent Organochlorine Contaminants in Harbor Seals, Phoca vitulina, from Alaska 49 Table 2.5. Mean Concentrations of Persistent Organochlorine Contaminants in Harbor Seals, Phoca vitulina, from the U.S. Outside of Alaska 51 Table 2.6. Mean Concentrations of Persistent Organochlorine Contaminants in Harbor Seals, Phoca vitulina, from Regions Outside of the U.S 60 SECTION III: ANNOTATED BIBLIOGRAPHY 78 Harbor Seal {Phoca vitulina) 79 Supplemental Information 137 iii 59 Tables page I. 1. Comparison of concentration ranges and means ± 1 standard deviation (ng/g wet mass) of chlorinated hydrocarbons measured in blubber of harbor seals in Alaska with other Alaska pinnpeds and with harbors seals from the Washington and Oregon coast 16 Figures page 1. Harbor Seal (Phoca vitulina) distribution in Alaska 3 2. Concentration values of cadmium in tissues of harbor seals 6 3. Concentration values of mercury in tissues of harbor seals 7 4. Concentration values of selenium in tissues of harbor seals 9 5. Concentration values of lead in tissues of harbor seals 10 6. Concentration values of organochlorine compounds in tissues of harbor seals 12. in Alaska 13 7. Concentration values of PCB- 1 53 in blubber samples of harbor seals 1 8. Concentration values of total DDT in liver samples of harbor seals in the United States 18 9. Concentration values of total DDT in blubber samples of harbor seals in Europe 1 10. Concentration values of total DDT measured in blubber samples of harbor seals in the N.E.United States and Canada 20 II. Concentration values of total DDT measured in cerebrum samples of harbor seals in the N.E.United States and Canada 21 Concentration values of total DDT measured in muscle samples of harbor seals in the N.E.United States and Canada 22 13 Concentration values of HCB in tissues of harbor seals in the United States, including Alaska 23 14. Concentration values of a-HCH and p-HCH in tissues of harbor seals 24 15. Concentration values of y-HCH in tissues of harbor seals 25 16. Concentration values of HCH in blubber of harbor seals in Alaska 26 17. Concentration values of dieldrin in blubber of harbor seals in the United States, including Alaska, and Europe 27 18. Concentration values of chlordanes in blubber of harbor seals in the United States, including Alaska 29 PREFACE The numbers of harbor seals {Phoca vitulina) have declined steadily and substantially over the last 2 decades in the Central and Western Gulf of Alaska, including Prince William Sound. Although the reasons for this decline have not been identified, hypotheses have included fishery interactions, changes in availability of food resources, human harvests, disease, increase in predation, increase in disturbance, and pollution. The decline of the harbor seals in this region of Alaska has coincided with the decline in the numbers of the Steller sea lion (Eumatopias jubatus), suggesting common reasons for the decrease in numbers of both pinniped species. Although the presence of contaminants has been suggested as one possible causative factor in the decline of both the harbor seal and Steller sea lion, very little information is readily available on contaminant concentrations in these animals. As an initial step in the development of a database that can be used to define the types of studies needed to address the possible role of anthropogenic contaminants in the decline of harbor seals, existing data and information on levels of contaminants in the harbor seals of Alaska, the contiguous United States, and other areas of the world were reviewed. This report provides references and current scientific literature, as well as “gray” literature and unpublished databases. Although the results of past research and monitoring in Alaska were emphasized, comparative information was available from Canada, other areas of the North Pacific, Northern Europe (particularly the Baltic Sea region), and the North Atlantic and is included in this report. Information on other marine mammal species is also included only as it lends to the interpretation of the harbor seal data. This report is divided into three sections: (1) a synthesis of information based on the review, (2) tables that summarize the published data, and (2) an annotated bibliography. The annotated bibliography is provided as a hard copy in this report, as well as on PC disk (Pro-Cite 3.1 for Windows). The Pro-Cite program will allow for entering additional references to this bibliography as they are published. This bibliography is divided into two parts, a database for references containing vital information on harbor seals, both in Alaska and other parts of the world, and a second database that includes other supplemental information, such as research relating to contaminants and other marine mammals, including other pinniped species and cetaceans. Currently, 432 references are entered, each including an abstract and a keyword index. Many of the “gray literature” reports have no abstracts; therefore, abstracts have been written for inclusion in this bibliography. The great majority of the information on contaminants and their potential health effects on harbor seals in this volume (47%) is derived from European studies. Additional information is derived from studies of other pinniped species and, in some cases, small cetaceans. Additional annotated bibliographies are planned and will include the following marine vertebrates: (1) additional marine mammal species, (2) sea turtles, and (3) colonial seabirds. These bibliographies will provide initial guides to the literature on contaminants in these organisms, and will be published in hard copy report form and on PC disks in Pro-cite 3.1 for Windows. PC disks containing the current bibliographies can be obtained by contacting: Paul R. Becker, NIST- Charleston, 219 Fort Johnson Road, Charleston, SC 29412 Telephone: 803-762-8503; Fax: 803-762-8700; Email: [email protected] V ACKNOWLEDGEMENTS The authors would like to thank The National Marine Mammal Laboratory, Seattle, WA, for providing the photograph on the cover page. DISCLAIMER Certain commercial equipment or instruments are identified in this paper to specify adequately the experimental procedures. Such identification does not imply recommendations or endorsement by the National Institute of Standards and Technology nor does it imply that the equipment or instruments are the best available for the purpose. ' 1 'H 'V.v 'i- SECTION I CONTAMINANTS IN ALASKA HARBOR SEALS: A SUMMARY OF THE AVAILABLE DATA 1 BACKGROUND Harbor seal {Phoca vitulina) distribution includes temperate and subarctic coastal waters of the North Pacific, North Atlantic, and contiguous seas. In Alaska, harbor seals inhabit the coastal areas and offshore islands fi-om Dixon Entrance to Kuskokwim Bay and Nunivak Island (Fig. 1). They are distributed in small groups (25-250 animals) along the shorelines of southeast Alaska, the south side of the Alaska Peninsula, the Aleutian Islands, and northern Bristol Bay; and in larger groups (>500 animals) in ^ords with tidewater glaciers in southeast and southcentral Alaska, and in major estuaries (Hoover-Miller, 1994). These animals occur primarily in coastal waters within 20 km of shore, often aggregate in estuaries and protected waters, and are thought to have strong affinity to specific haulout areas. Haulout sites include sand beaches, tidal mud flats, offshore rocks and reefs, and man-made objects. Harbor seals are sedentary animals that feed, reproduce, and rest near or on shore and are top-level trophic consumers. Because harbor seals feed at high trophic levels (fish, octopi, etc.), they have the potential for relatively high organochlorine contaminant concentrations in their tissues and are good indicators of bioaccumulation. Anthropogenic contaminants and their impacts on marine mammals have become a widespread concern among biologists over the last several decades. Organochlorine pollutants (e.g., dichlorodiphenyltirchloroethane (DDT), polychlorinated