I attended a great virtual lecture this morning offered by the Hebridean Whale and Dolphin Trust: The Basking Shark – The Road Back From Oblivion with Colin Speedie
Many of us have heard about Whale sharks – which are whale sized, but not actual sharks. Basking sharks are in the same category. Both are filter feeders, with Baskin sharks feeding mainly on zooplankton. Basking sharks average 26 feet long and are a little odd looking in a cute- fishy sort of way. Probably the most distinctive features are their sort of pointed snout, wide mouth and massive dorsal fin.
“Though they’re spotted at the surface, basking sharks can spend up to 90 percent of their time underwater, Ebert said. They often surface to feed on copepods, a type of zooplankton that NOAA fisheries biologist Heidi Dewar, also one of the paper’s coauthors, describes as “the cows of the sea” for their role as grazers of the ocean’s photosynthesizing primary producers.” (Bay Nature 4/12/22)
They are also endangered. They used to be seen frequently off the CA coast and up into Canada, now sightings are rare on both coasts.
“During the 20th century, basking sharks were targeted by fisheries in both the Pacific and Atlantic Oceans for their highly profitable oily livers and large fins.” (Bay Nature 4/12/22)
One area that still has a noticeable size population is the eastern Atlantic, particularly the waters in and around Ireland and Scotland where Colin Speedie has been studying them, with help from the HWDT.
Amazingly there was a sighting about a week ago in Southern California. The video is very cool and gives you a real sense of their size and gentleness.

Pair of 25-foot basking sharks spotted off California coast: https://www.today.com/video/rare-sighting-of-basking-sharks-caught-on-camera-204700741776
Case study: Basking sharks in Scottish waters: https://marine.gov.scot/sma/assessment/case-study-basking-sharks-scottish-waters
Basking shark Cetorhinus maximus: https://scottishwildlifetrust.org.uk/species/basking-shark/
The Second-Largest Fish In the Ocean Seems to be In Decline, Bay Nature: https://baynature.org/2022/04/12/the-second-largest-fish-in-the-ocean-seems-to-be-in-decline/
Colin Speedie / A Sea Monster’s Tale https://www.facebook.com/SeaMonstersTale