Spotted dolphins (Stenella attenuata) encircled within a tuna
purse-seine net in the eastern tropical Pacific. Fishermen use
the association of tunas, dolphins and seabirds to locate large
yellowfin tuna schools. The dolphins and tuna are both captured
in the net. Massive incidental mortality of dolphins in the
early years of this fishery led to population declines and
designation of this stock as depleted. Mortality is now much
lower, but federal scientists said it is unclear to what extent
the dolphin populations have recovered. / Southwest Fisheries
Science Center/National Marine Fisheries Service