Results from examination of dead humpback whale in Southern Puget Sound, March 29, 2017

Yesterday (March 29th) Cascadia Research and Washington Department of Fish and Wildlife Marine Mammal Investigations, with assistance from SR3 and the MaST Center examined the humpback whale that was found dead in Southern Puget Sound on Tuesday. The 29 1/2 foot yearling female is confirmed to be the same individual sighted live in Hammersley Inlet on the 25th and Nisqually on the 26th. It appears that this whale live stranded and died in the same location in which is was found on Tuesday; this stranding event may have occurred as early as overnight on Monday.  The most significant finding was severe emaciation, with dry fibrous blubber, minimal subcutaneous fat stores, and decreased gastrointestinal contents. There was no evidence of underlying disease in the examined tissues, but these will be further analyzed in the coming days/weeks and may provide additional information regarding the cause of the poor body condition. There was also a moderate skin condition of undetermined origin, which will also be further investigated. The skeleton will be used for educational purposes and the whale has been moved to a secure location to facilitate the collection of the bones. We would like extend a big thank you the National Fish and Oyster Company for their assistance with moving the whale yesterday afternoon.

In recent years humpback whales have been returning in larger numbers and throughout the year to the Salish Sea including Puget Sound. Cascadia Research has over 3,000 humpback whales individually identified by their fluke markings and have used this to track humpback whale recovery that had been increasing at 7% per year recovering from whaling that continued through 1966. They used to be common to the waters over a 100 years ago but then commercial whaling wiped them out including a short period where whaling station operated through the winter for several years specifically targeting the humpback whales in the Salish Sea and not just those off the coast. Sightings of humpback whales in the Salish Sea have been become more common in the last 5 years including recent sightings of several whales in southern and central Puget Sound in recent days and weeks.
The whale that recently died had been swimming around the Salish Sea for a number of days and likely may have recently returned from a winter breeding area. Humpback whales typically fast during much of the winter and are often thin at the time of their return, but this animal was much thinner than is normal even for this time of the year.