<P> Collapsed or collapsing dorsal fins are rare in most wild populations and usually result from a serious injury to the fin , such as from being shot or colliding with a vessel . After the 1989 Exxon Valdez oil spill , the dorsal fins of two male resident killer whales who had been exposed to the oil collapsed , and the animals subsequently died . In 2002 , the dorsal fin of a stranded killer whale showed signs of collapse after three days but regained its natural upright appearance as soon as the orca resumed strong normal swimming upon release . </P>
<P> Collapsed or collapsing dorsal fins are rare in most wild populations and usually result from a serious injury to the fin , such as from being shot or colliding with a vessel . After the 1989 Exxon Valdez oil spill , the dorsal fins of two male resident killer whales who had been exposed to the oil collapsed , and the animals subsequently died . In 2002 , the dorsal fin of a stranded killer whale showed signs of collapse after three days but regained its natural upright appearance as soon as the orca resumed strong normal swimming upon release . </P>
why do orcas have collapsed dorsal fins in the wild
why do orcas have collapsed dorsal fins in the wild
a serious injury to the fin , such as from being shot or colliding with a vessel
a serious injury to the fin , such as from being shot or colliding with a vessel