Dead Salmon Shark (Lamna ditropis) Near 2nd Cape

Observation by Jaclyn Christensen:

Dead shark found on the beach near north river beach towards second cape. Other smaller whales have been observed on the beach, all different species: humpback, porpoise, and another that is either a gray or minke whale. Other dead marine and ocean life include walrus and sea otter.

Comments from LEO Editors:

In reviewing the archive in LEO Network, there are only two shark stranding events that have been reported from Alaska. Both were Pacific sleeper sharks, one from King Cove in June 2012 and another in Shishmaref in September 2014. You can see both of these observations attached. The salmon shark, Lamna ditropis, is a member of the same family as the great white, Carcharodon carcharias. Salmon sharks range across the North Pacific and as far north as the the Bering Sea (see range maps). They do feed on salmon but also squid, sablefish, and herring. According to an article from the Sanctuary Integrated Monitoring Network (SIMoN), occassional strandings of salmon sharks have been reported along the California coast:

Juvenile salmon sharks (Lamna ditropis) are known to get stranded, or wash up dead, along the central and southern California coast during late summer and early fall. The reason for this is not fully understood. A recent study examined tissues from 19 stranded sharks, and histopathology revealed meningitis or meningoencephalitis in many of the shark brains, and bacteria (Carnobacterium sp.) in brain and other tissues. It is suggested that the bacterial brain infection is a significant cause of mortality in juvenile salmon sharks found stranded along the coast. These strandings are not of great concern due to their sporadic nature, and have not included massive die-offs.

We have found no evidence of other salmon shark strandings in Alaska. Members are invited to share any experiences or information they have on this topic. We have also shared this observation with the Marine Mammal Stranding Network and shark researcher Bruce Wright for any additional comments. What makes this observation even more interesting is that the shark was found near a number of stranded marine mammals. This observation, also by Jaclyn Christensen, can be viewed as an attachment.

For more information about salmon sharks, see article Hot blooded predator: The Salmon Shark Alaska's Salmon Sharks in the Alaska Fish and Wildlife News by Amy Carroll. Mike Brubaker