Killer Whales Dorsal Fin – Collapsed

Killer whale

A wild orca often travels far, and quickly, in deep water. The water provides pressure to the fin, keeping the tissues inside healthy and straight, and encouraging the dorsal fin to remain straight. However, it is not impossible for a wild orca’s dorsal fin to collapse or become bent. A study in 1998 of killer whales in New Zealand showed a relatively high rate (23%) of collapsing, collapsed, or even bent or wavy dorsal fins, and noted that this was higher than that observed in populations in British Columbia or Norway. It has been found from a well-studied group of wild killer whales (the ones in our viewing area) off the coast of British Columbia that the total rate of dorsal fin collapse is around 1%.  This is only the second collapsed fin I have seen in ten years.  Researchers have theorized that dorsal fin collapse in wild whales may be due to age, stress or altercations with other killer whales.