Status and distribution of sea otters in Alaska

Lensink, Calvin

One hundred and seventy years of exploitation exterminated the sea otter in most of its original range, but small groups survived in widely scattered areas. In the aggregate these survivors may have numbered between 200 and 500 individuals. Since 1911, when protection was extended to sea otters, they appear to have increased at a rate which may be near their maximum capacity for recruitment. They may now number about 40,000 animals. The present status of the otter is such that we can expect a rapid expansion in numbers from the Andreanof Islands eastward. West of the Andreanof Islands the habitat is limited and the population may already be near the carrying capacity. Here, sea otters are perhaps as abundant as they were before exploitation by the Russians. On Amchitka Island the evidence indicates that a high population has resulted in increased mortality and a lowered reproductive rate. Both the historical and present distribution patterns appear to indicate that the primary factor in the sea otter's habitat is the amount of shallow water available in which the otter can obtain food. The evidence suggests that the coexistence of kelp and sea otters may be at least partially coincidental. However, reliable information on nearly all phases of sea otter ecology is lacking and present survey figures are not adequate. Population movements, seasonal and otherwise, are known to exist, but are not yet understood. Such movements could have an important bearing on population estimates.

Status and distribution of sea otters in Alaska

Series