Synopsis of the history of sea otter conservation in the United States

In the late 1860s, declining US sea otter populations elicited concern because of prior excessive harvests. Congress mandated protection of Alaskan sea otters in 1868, but hunting continued unrestrained. The Fur Seal Treaty of 1911 (abrogated in 1941) protected sea otters in international waters, but was not applicable to most sea otter habitats and failed to terminate all legal sea otter harvests. Between 1941 and 1972 only the State of California was consistently engaged in sea otter conservation, based on a 1913 state law. Trends in cultural values toward protection of species based on imperiled status rather than economics led to the Marine Mammal Protection Act (1972), giving sea otters unambiguous protection in all US territorial waters. Sea otter habitat protection by the US government began in the 1890s. State marine protected areas potentially support sea otter conservation, particularly when paired with adjacent federal protected entities in or near sea otter habitat.