MARINE MAMMAL COMMISSION - Annual Repon for 1998 



of the translocated sea otters and provide a buffer 

 against possible adverse activities that might occur 

 outside that zone. It required that the area surround- 

 ing the translocation zone be designated as a manage- 

 ment zone from which sea otters would be excluded 

 by non-lethal means to protect fishery resources. 



The Fish and Wildlife Service, in consultation with 

 the Marine Mammal Commission, the California 

 Coastal Commission, and the California Department 

 of Fish and Game, subsequently developed a plan to 

 establish a reserve sea otter colony at San Nicolas 

 Island in the California Channel Islands. In August 

 1987, the California Department of Fish and Game 

 and the Fish and Wildlife Service concluded a memo- 

 randum of understanding on the translocation and 

 study of sea otters, and the Fish and Wildlife Service 

 began translocating sea otters to San Nicolas Island. 



Ultimately, 139 sea otters were captured along the 

 California coast and moved to San Nicolas Island 

 before the translocation effort was halted in mid- 1990. 

 Most of the animals subsequently left the area or 

 disappeared; 36 returned to the mainland range and 1 1 

 were captured in the management zone and returned 

 to the mainland range. A few sea otters have re- 

 mained in the water around San Nicolas. Although at 

 least 50 pups are known to have been born at San 

 Nicolas Island, the colony has not grown and remains 

 static at about 17 individuals. The reasons for the 

 lack of growth are unknown; possibilities include 

 mortality from natural causes, entrapment in lobster 

 traps and pots, illegal taking, and dispersal of animals 

 after weaning. 



Update of the Southern Sea Otter Recovery Plan 



— In 1989 the Fish and Wildlife Service reconstituted 

 the Southern Sea Otter Recovery Team to review and 

 recommend changes necessary to update the southern 

 sea otter recovery plan. This action was precipitated, 

 in part, by the 1989 Exxon Valdez oil spill and the 

 subsequent realization that the entire California sea 

 otter population could be jeopardized by a similar 

 large oil spill. 



Based on the recovery team's recommendations, 

 the Fish and Wildlife Service drafted a plan update 

 and in August 1991 provided it to the Commission 

 and others for review and comment. As discussed in 



previous annual reports, the Commission in November 

 1991 commented to the Service that the draft did not 

 adequately address several important issues and 

 recommended that the Service prepare a second draft 

 for review. 



Based on recommendations from the recovery 

 team, the Service revised the draft update, and on 3 

 July 1996 provided a second draft to the Commission 

 and others for comment. The Commission forwarded 

 comments on the revised draft to the Service on 24 

 September 1996. Among other things, the Commis- 

 sion pointed out that the document differed in several 

 important ways from the original recovery plan 

 adopted in 1982. For example, it proposed to discon- 

 tinue the "zonal" management approach embodied 

 both in the original recovery plan and in Public Law 

 99-625, which provided the authority for establishing 

 the reserve sea otter colony at San Nicolas Island and 

 for preventing range expansion elsewhere south of 

 Point Conception. 



Population Decline — When the California sea 

 otter population was listed as threatened n 1977, it 

 was assumed that the population was increasing and 

 would continue to increase at about 5 percent a year 

 for the foreseeable future. As noted in previous 

 Commission reports, however, subsequent studies 

 indicated that substantial numbers of sea otters were 

 being caught and killed incidentally in coastal gill and 

 trammel net fisheries and that this incidental take was 

 sufficient to stop and possibly reverse the population 

 increase (see Bishop 1985, Henry 1986, and Hatfield 

 1991, Appendix B). In addition, thousands of sea- 

 birds and non-target fish, as well as sea otters and 

 other marine mammals, were being caught and killed 

 in these fisheries. In response, the state of California, 

 beginning in 1982, enacted a series of regulations 

 prohibiting the use of gill and trammel nets in areas 

 where seabirds, sea otters, and other marine mammals 

 were likely to be caught and killed. These prohibi- 

 tions substantially reduced the incidental take of sea 

 otters, and in the mid-1980s the population increase 

 and range expansion both resumed. The expected 

 range expansion was one of the factors that led to the 

 zonal management plan implemented by the Fish and 

 Wildlife Service in 1987. 



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