Gray whale deaths - April 2010

John Calambokidis and Jessie Huggins, Cascadia Research

Four gray whales have died in Puget Sound in the last two weeks raising the concern of researchers than monitor gray whales and the health of marine mammals in the region. The total number remains well below the peak numbers documented in big mortality year and  the 5 that have died so far in 2010 is still under the average for an entire year, the four in two weeks in Puget Sound is more clustered than has generally been seen in the past. These strandings have been investigated by the Northwest Marine Mammal Stranding Network including Cascadia Research (CRC), National Marine Fisheries Service (NMFS), Central Puget Sound Marine Mammal Stranding Network (CPSMMSN), and Washington Department of Fish and Wildlife (WDFW).

The five Gray whales that have died so far in 2010 include:

  1. CRC 1025. A gray whale calf found dead on the Washington outer coast and examined 9 February 2010.
  2. CRC-1034: A young gray whale (26 ft) reported stranded alive on 4-Apr-2010 in Deer Creek near Shelton. The animal died that day and was necropsied by Cascadia on 5-April 2010 and which proved to be emaciated and malnourished. Photo-ID of this whale revealed it was the same whale that had been seen on 25 March 2010 in the Nisqually River.
  3. 10Er11AprSK-01: A 40 foot adult female found 11-Apr-2010 near Fidalgo Island. towed by Deception Pass Tours and Central Puget Sound Marine Mammal Stranding Network on 12-Apr and examined by CRC and CPSMMSN. It was emaciated with little oil in the blubber, and the stomach and intestines were filled with woody debris. Photographic identification revealed it matched to photos taken  in West Seattle on 27 March.
  4. 10Er12AprSK-02: A juvenile male gray whale first reported on 10 April 2010 dead and stranded in Samish Bay, Skagit County: It was towed by WDFW and Whatcom county marine mammal stranding network on 12 April to secluded location and necropsied on 14 April by CRC and WCMMSN. This animal was thin with little oil in the blubber, it had some stomach content but little actual food.
  5. West Seattle whale (CRC-1035):  Washed up near Fauntleroy ferry terminal in W Seattle. Examination conducted 18 April 2010, see report of examination.

At this point while these deaths are important to monitor, we do not consider them alarming and they do not appear to reflect any specific problem in Puget Sound. None of the whales that have died are the regular animals that visit Washington waters on a regular basis each year. These appear to be stragglers from the larger gray whale population of close to 20,000 gray whales that typically migrate north past Washington each spring after fasting several months in warmer southern waters they use as their breeding area. This makes April a period when whales that did not get enough food on their Alaskan feeding grounds may be running out of their reserves. A major mortality event occurred in 1999 and 2000 in which 50 gray whales died in Washington State in the two years combined.

 

Cascadia biologists begin examination of CRC-1034.

Measurements being taken of of whale near Whidbey Island on 13 April 2010

Measurements being taken on 14 April 2010 of whale that stranded in Samish Bay.