Evaluation of sea otter capture after the Exxon Valdez oil spill, Prince William Sound, Alaska

After the T/V Exxon Valdez oil spill into Prince William Sound, the U.S. Fish and Wildlife Service and Exxon Company, U.S.A., began rescuing sea otters (Enhydra lutris). The primary objective of this operation was to capture live, oiled sea otters for cleaning and rehabilitation. Between 30 March and 29 May 1989, 139 live sea otters were captured in the sound and transported to rehabilitation centers in Valdez, Alaska. Within the first 15 days of capture operations, 122 (88%) otters were captured. Most sea otters were captured near Knight, Green, and Evans islands in the western sound. The primary capture method consisted of dipnetting otters out of water and off beaches. While capture rates declined over time, survival of captured otters increased as the interval from spill date to capture date increased. The relative degree of oiling observed for each otter captured declined over time. Declining capture rates led to the use of tangle nets. The evidence suggests the greatest threat to sea otters in Prince William Sound occurred within the first 3 weeks after the spill. Thus, in the future, the authors believe rescue efforts should begin as soon as possible after an oil spill in sea otter habitat. Further, preemptive capture and relocation of sea otters in Prince William Sound may have increased the number of otters that could have survived this event.