Scott Pegau from the Oil Spill Recovery Institute in Cordova saw four mola mola (ocean sunfish) off Hinchinbrook Island while conducting forage fish surveys this past week (August 5, 2015).
Ocean sunfish, also known as Mola Mola, are the heaviest known bony fish in the world. The average adult weight is between 247 and 1,000 kg (545–2,205 lb). The species is native to tropical and temperate waters and are observed around the world (click here to view an ocean sunfish observation distribution map). Sunfish exhibit surface basking behavior, where they swim on their side exposing their largest profile towards the sun. It is during these times they are usually noticed by people on boats. Ocean sunfish feed on jellyfish, and are prey for sharks, Orca whales, and sea lions.
What is unusual about this sighting is that ocean sunfish are typically found in water warmer than 10 °C (50 °F). They are rarely observed in Alaskan waters. Mola scientists think that one major factor that drives ocean sunfish migrations is temperature. Documenting regular as well as unusual sightings may help scientists better understand what is influencing the range and migration of these interesting sea creatures.
For more on what has been observed fishwise in the Gulf of Alaska, see this article in the Washington Post from 2014.
Photo Credit: Huge ocean sunfish (mola mola) at Outer Bay exhibit, Monterey Bay Aquarium, California. 25 December 2006 by Fred Hsu (Wikipedia:User:Fredhsu on [http://en.wikipedia.org]