. The Canadian field-naturalist. Natural history. 1997 Watson, Ellis, Smith, and Ford: Status of the Sea Otter 283 10000 N CO a o +-» a o a. 1000 r 100. 10 1975 1980 1985 1990 1995 2000 Year Figure 4. Growth of the British Columbia Sea Otter popu- lation from 1977-1995. The population has increased at a rate of per year (r2=) since 1977. Estimates of the Sea Otter population off of Goose Island are not included, because the size of this group is poorly known. Fishery Conflicts Sea Otters are capable of limiting the abundance of many commercial species of shellfish (Johnson 1982; Est
. The Canadian field-naturalist. Natural history. 1997 Watson, Ellis, Smith, and Ford: Status of the Sea Otter 283 10000 N CO a o +-» a o a. 1000 r 100. 10 1975 1980 1985 1990 1995 2000 Year Figure 4. Growth of the British Columbia Sea Otter popu- lation from 1977-1995. The population has increased at a rate of per year (r2=) since 1977. Estimates of the Sea Otter population off of Goose Island are not included, because the size of this group is poorly known. Fishery Conflicts Sea Otters are capable of limiting the abundance of many commercial species of shellfish (Johnson 1982; Estes and VanBlaricom 1985; Pitcher 1989). This has resulted in considerable conflict between commercial shellfish harvesters and Sea Otters (Estes and VanBlaricom 1985). Sea Otters have had a significant effect upon the Pismo clam fishery in central California (Wendell et al. 1986), clam densi- ty in Alaska (Kvitek et al. 1992; Kvitek and Oliver 1992) and sea urchin abundance in parts of British Columbia (Morris et al. 1979, 1981; Breen et al. 1982; Watson 1993). Conflicts over Sea Otters and shellfish stocks are not yet a problem in British Columbia, but can be anticipated as the geographic range of Sea Otters increases (Watson and Smith 1996). Incidental Take of Sea Otters Gill-net fisheries in California have probably lim- ited or even reduced the southern Sea Otter popula- tion (Wendell et al. 1985). Incidental take of Sea Otters in net-fisheries in southeast Alaska and Prince William Sound have been reported, but the impact on the Sea Otter population is unknown (Matkin and Fay 1980; Simon-Jackson 1986). Gill-nets are used in both salmon and herring fisheries in British Columbia, but incidental take of Sea Otters has not been reported. The expansion of Sea Otters into areas where gill-net fisheries, particularly for salmon, occur could have local effects on Sea Otter abundance. Special Significance of the Species Once on the verge of extinction, Sea Otters have made a remar
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