For the 2nd time in recent weeks, examination of a stranded whale confirmed it was likely the victim of a ship strike in Washington State. Examinations of a minke whale that was found floating in the San Juan Islands on 5 October 2022 and of a humpback whale that was first reported on the same day on the Washington outer coast, showed clear indications of blunt force trauma likely as a result of a ship strike. This adds to three gray whales that were documented earlier in the year in Washington that were also likely the victim of ship strikes.
Ship strikes have been an increasing cause of death of large whales in Washington especially since the early 2000s. The recent documented ship strikes are particularly troubling because these known cases represent a small proportion of the true number of ship strike deaths. Most whales killed by ship strikes are not observed and carcasses often sink and do not wash up to be examined like the two in the past week.
Both whales were examined by members of the West Coast Marine Mammal Stranding Network. The minke whale was examined 7 October by a combined team led by the Whale Museum and Cascadia Research (see https://whalemuseum.org/pages/marine-mammal-stranding-network). The adult female minke whale had recently fed and appeared in good health but had severe bruising and broken vertebra and ribs. The humpback whale stranded in Olympic National Park and was examined by Cascadia Research and WDFW on 9 October 2022. It was a 26-foot young female, likely a recently weaned calf or yearling, that also had stomach with fish. She had severe bruising and internal bleeding and the combination of the impact and decomposition had resulted in some organs being expelled.
Click below to view a poster presented at the 24th Biennial Conference on the Biology of Marine Mammals August 1-5, 2022.
Ship strikes on large whales in the Salish Sea