1991 Marine Mammal Observer Program for the Salmon Driftnet Fishery of Prince William Sound Alaska

The 1991 observer data suggests that marine mammal encounters (approaching within 10 meters of a net) are common in this fishery, but rarely fatal. Steller sea lions and harbor seals appear to be attracted to the gillnets where they scavenge netted salmon. Sea otters and cetaceans may inadvertently encounter nets as they pass through a fishing area. Mammals became entangled in less than 1 % of the total observed sets, and 85% of the entangled animals were able to release themselves unharmed or to be released with fishermen's assistance. Entanglements resulted in serious injury or death to marine mammals in less than 0.1 % of sets observed. Seven marine mammals (four porpoises, two sea lions, and one harbor seal) died or were seriously injured in the 5875 observed sets. Because so few kills were observed, extrapolation of the observer data is statistically difficult, and results in wide confidence intervals.