Ship Strike Suspected as Cause of Death of Two Whales in Alaska

Alaska stranding network members, including Glacier Bay National Park, Alaska Veterinary Pathology Services, and NOAA Fisheries, necropsied two humpback whales in Icy Strait in July 2024.

On July 3, NOAA Fisheries received a report of a floating humpback whale, which ultimately washed ashore near Elfin Cove. Postmortem examination of this male humpback whale found injuries consistent with a vessel strike as the cause of death. Measurements collected indicate he was likely a yearling.

The second humpback whale was reported floating near Point Adolphus on July 22. Glacier Bay National Park biologists collected photos of the flukes, which were used to identify this whale as SEAK-1731 in Happywhale. This 23-year-old female was first spotted as a calf in 2001 and has a sighting history in Southeast Alaska and Hawaii. The necropsy report is pending, but postmortem examination found SEAK-1731 was 48-feet long and was pregnant at the time of her death. While the necropsy team found evidence suggesting blunt force trauma from a possible vessel strike, the cause of death could not be confirmed at the time of the necropsy.

The NOAA stranding hotline received several reports of vessels colliding with humpback whales in the Icy Strait area this summer. However, given when and where these reported vessel strikes occurred, it is unlikely they were linked to the two humpback whale strandings.

The Alaska humpback whale approach regulationrequires that vessels:

• Not approach within 100 yards of a humpback whale
• Not place your vessel in the path of oncoming humpback whales causing them to surface within 100 yards of your vessel
• Not disrupt the normal behavior or prior activity of a whale
• Operate your vessel at a slow, safe speed when near a humpback whale

Some areas in Southeast Alaska, like Point Adolphus, are predictable places to see humpback whales. In the spring, summer, and fall, vessel operators should always assume that several humpback whales are present in these areas. Reducing speed gives the vessel operator more time to spot whales, which can help prevent surprise close encounters. Slowing down also gives the whales more time to react and move away.

Report all dead, injured, or entangled marine mammals to NOAA's 24-hour stranding hotline 1-877-925-7773.