An Ocean Blueprint for the 21st Century - California Ocean ...

Box 20.1 Making a Case for Ecosystem-based Management: The Steller Sea LionThe story of the Steller sea lion illustrates the conflictsthat can arise between human activities andprotection of marine mammals. The Steller sea lion isthe largest of the sea lions and is found along coastalareas of the northern Pacific Rim. Its primary sources offood are groundfish, including pollock and mackerel,and cephalopods, including octopus and squid. Sincethe mid-1970s, the western population near Alaska hasdeclined by about 85 percent (Figure 20.1). i Analysesindicate that the decline may be due in part to environmentalchanges, legal and illegal hunting, predationby killer whales, competition with fishermen forfood, and incidental catch in fisheries. A 2003 reportby the National Research Council found that none ofthese causes could be ruled out and called for scientifically-designedadaptive management experiments tofind out more. iiFigure 20.1 Sea Lion Populations in DangerThousands of AnimalsOver One Year OldUnder the Marine Mammal Protection Act, theNational Oceanic and Atmospheric Administration(NOAA) is responsible for managing Steller sea lions.It is also the agency responsible for management ofAlaskan fisheries, resulting in potential statutory conflicts.In 1991, a number of environmental groups sued NOAA for failing to take into accountthe potential role of Alaskan fisheries in the decline of the Steller sea lion. After years of litigation,the problem has yet to be resolved to the satisfaction of any of the litigants. In addition,Steller sea lions were listed under the Endangered Species Act (the western population asendangered and the eastern as threatened), adding that statute’s requirements to the mix.The continued decline of the Steller sea lion population highlights the importance ofmoving toward an ecosystem-based management approach, where such factors as predators,quality and quantity of food, essential habitat, and incidental catch are all weighed whendeciding the best course of action for protection of a species. In addition, a more ecosystembasedfocus would have identified the problem much more quickly, enabling managers andscientists to develop a comprehensive and timely research strategy to determine the variouscauses of the decline and develop a management regime to address the problems. Instead,the situation was allowed to reach a crisis stage, requiring emergency measures.2502001501005001965 19701975198019851990Total Alaskan Population Western Alaskan StockAlthough Steller sea lions have been protected since the early1970s, the Alaskan populations have continued to decline,particularly those located along the Aleutian Islands. This declinecannot be traced to a single cause, underscoring the need for anecosystem-based approach for protecting these animals.Source: National Oceanic and Atmospheric Administration. (Accessed January 2004).19952000i Marine Mammal Commission. Annual Report to Congress. Washington, DC, 2002.ii National Research Council. The Decline of the Steller Sea Lion in Alaskan Waters: Untangling Food Webs and FishingNets. Washington, DC: National Academy Press, 2003.For marine mammals and endangered marine species, fisheries bycatch, and to alesser degree hunting, would be at the top of the list of risks. For other species, impactson breeding and foraging habitat are critical. For certain highly endangered species, suchas North Atlantic right whales and manatees, reduction of ship strikes is a pressing need.Once the major risks are identified, managers can use a combination of the tools availableto them to address these concerns. For example, the use of marine protected areas hasbeen shown to be effective in addressing a number of the impacts on protected species.Unfortunately, in most cases little is known about the relative effects of different factorson the survival and recovery of a protected species. The lack of baseline biological data onmost marine mammals and endangered marine species, coupled with limited stock assess-C HAPTER 20: PROTECTING M ARINE M AMMALS AND E NDANGERED M ARINE S PECIES317