Chapter VII — Marine Mammal Management in Alaska 



small cetaceans, may have declined as well. As noted 

 in Chapter H, the North Pacific fur seal and the 

 Steller sea lion have declined so precipitously that 

 they have been listed, respectively, as depleted under 

 the Marine Mammal Protection Act and threatened 

 under the Endangered Species Act. 



The cause or causes of the declines are not clear. 

 They may include: (1) entanglement in lost or dis- 

 carded fishing gear; (2) incidental take in driftnet, 

 trawl, and other fisheries; (3) decreased food avail- 

 ability due to overharvesting of pollock or other 

 finfish; (4) decreased food availability due to climate 

 or other natural changes affecting the distribution, 

 abundance, or productivity of important prey species; 

 (5) diseases; and (6) environmental pollution. 



Many studies have been and are being done to 

 assess and monitor the status of and annual variation 

 in marine mammal, seabird, and fish populations in 

 the Bering Sea and Gulf of Alaska. Some scientists 

 are also trying to determine how bottom topography, 

 currents, wind, and other physical factors affect 

 nutrient cycling, primary and secondary productivity, 

 and other ecosystem processes. With few exceptions, 

 these programs have been carried out independently. 

 Particularly in the case of seabirds and marine mam- 

 mals, most research has been concerned with species- 

 specific studies of the life history, ecology, behavior, 

 and human use patterns. Little research has been 

 done on the interrelationships among fish, bird, and 

 mammal species and the physical and chemical 

 oceanographic, geologic, and climatological factors 

 that may affect them or the ecosystem of which they 

 are a part. 



In the 1970s and 1980s, two multi-year studies 

 examined the oceanography and productivity of the 

 Bering Sea. The first, entitled Processes and Resourc- 

 es of the Bering Sea Shelf, or PROBES, was conduct- 

 ed by researchers at the University of Alaska with 

 support from the National Science Foundation. The 

 PROBES study investigated interactions between and 

 among the climatological, chemical and physical 

 oceanographic, and biological processes " (mainly 

 primary and secondary production) that affect and 

 support the Bering Sea ecosystem. In considering 

 higher trophic level interactions and effects, however, 

 the PROBES study only examined interactions be- 



tween seabirds and oceanographic factors in the 

 Bering Sea. Overall, PROBES effectively developed 

 hypotheses and presented informafion on the energy 

 transfer fi-om the base of the food web to fish and 

 seabirds, but the study did not consider other higher 

 trophic level species. 



The second study, entitled the "Inner Shelf Trans- 

 fer and Recycling program," or ISHTAR, was carried 

 out in the early 1980s by scientists from a number of 

 institutions, including the Universities of Alaska, 

 South Florida, Washington, and others, and was also 

 supported by the National Science Foundation. 

 ISHTAR examined carbon and nitrogen cycling in the 

 Bering and Chukchi Seas and its effect on primary 

 production in the Arctic Ocean. It provided signifi- 

 cant insight into the processes that support the food 

 webs, but, like PROBES, it did not examine interac- 

 tions with the higher trophic levels. 



In 1979, the Marine Mammal Commission provid- 

 ed funds to the North Pacific Fishery Management 

 Council to help support a review of available data on 

 the status, feeding habits, and habitat requirements of 

 marine mammals in the Bering Sea. The review was 

 conducted by the Alaska Department of Fish and 

 Game under contract to the Council, and was complet- 

 ed in 1982. The report identified information gaps 

 and recommended that a workshop be held to deter- 

 mine how best to obtain needed data and how avail- 

 able data could be used to improve and coordinate 

 management of marine mammals and fisheries in the 

 Bering Sea. The workshop, co-sponsored by the 

 Commission, the Council, and the Alaska Sea Grant 

 College Program, was held in Anchorage, Alaska, in 

 October 1983. The objectives of the workshop were 

 to review existing knowledge of interactions between 

 marine mammals and fisheries in the southeastern 

 Bering Sea, identify critical data gaps and uncertain- 

 ties concerning ongoing and planned research and 

 monitoring programs, and describe actions that should 

 be taken to better meet the goals of the Marine 

 Mammal Protection Act and the Magnuson Fishery 

 Conservation and Management Act. The workshop 

 report, published in 1984 (see Appendix C, Melteff 

 and Rosenburg 1984), provides a summary of avail- 

 able information concerning fisheries, fish stocks, and 

 marine mammals in the Bering Sea, and identifies 

 priority research and management needs. 



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