Why does the orca dorsal fin fall in captivity?

Answer 1

Most male captive Orcas, and some females, have collapsed (droopy) dorsal fins. Several theories exist as to why this happens. A dorsal fin is held erect by collagen, or compressed lipid cells. The collagen normally hardens in late adolescence.

One theory is that in deep ocean waters, the pressure the water exerts on the fin allows it to remain supported while the collagen hardens. In captivity, however, shallow tanks lack sufficient water pressure to produce this effect, and the fin collapses before the collagen solidifies. According to another theory, the Orca is almost always in a state of turning in a tank, since it is not large enough to allow swimming in one direction for any normal duration. The constant turning exerts pressure on the dorsal fin, which in turn causes it to collapse.

Other possible explanations include alterations in water balance caused by the stresses of captivity or dietary changes, lowered blood pressure due to reduced activity patterns, or overheating of the collagen brought on by greater exposure of the fin to the ambient air.

In the wild, dorsal fin collapse is rare, and the deformity is believed to have a different set of causes than in captivity. In wild Orcas, it usually results from a serious injury to the fin. After the 1989 Exxon Valdez oil spill, the dorsal fins of two male resident Orcas who had been exposed to the oil collapsed, and the animals subsequently died. In 2002, the dorsal fin of a stranded Orca showed signs of collapse after three days, but regained its natural upright appearance as soon as the whale resumed strong normal swimming upon release.

Answer 2

Many people are not sure but I am. Water and water pressure supports the orca's dorsal fin in the wild. The pressure levels are too low for the male orcas in captivity, so the weight of the dorsal fin causes it to flop over.

Answer 3

over time gravity pulls the orca's fin down in an arc. this occurs more in captive whales because they spend more time near the surface where the gravity is stronger than it is underwater.

Answer 4

Its either because of the water pressure in the tank or a lack of calcium in their diet which keeps the cartilage in their dorsal strong

Answer 5

Because they're nervous and really scared. Being in a different environment has an effect too.