Scientists are probing the unexplained deaths of a fourth and fifth whale on the US and Canadian west coasts since mid-May. "Spike," a young female humpback first documented by scientists in 2018, was found washed ashore near Vancouver Island on Sunday, just a day after a male humpback calf was found dead near California's Fort Bragg, reports the Guardian. Another juvenile male humpback was found dead south of Fort Bragg on Sept. 12. This follows the discovery of two other dead whales, a beaked whale and sperm whale, in the area on May 15 and July 29, respectively, per the Press Democrat. Scientists are studying the more recent carcasses in the hope of identifying a cause of death and possible risks to other animals, perhaps as a result of a changing climate.
"The opportunity to learn from a dead whale is a rarity," as "dead whales usually sink to the bottom of the ocean," Jackie Hildering with British Columbia's Marine Education and Research Society tells the CBC. Samples of skin, blubber, and the baleen were taken from the male humpback, along with the pelvic bones, which will be analyzed at the California Academy of Sciences. The calf appeared to be well-fed, as did the other who washed ashore in September, per the Press Democrat. Whales are commonly injured or killed in ship strikes, and a laceration was seen on the right side of the calf found Saturday. But "nothing obvious points to ship strike at this time," Sarah Grimes of the Noyo Center for Marine Science tells the Mendocino Voice. "It sucks that this keeps happening," she adds. "It breaks my heart."
Fisheries and Oceans Canada is investigating the death of Spike, found hundreds of miles away on the north side of BC's Malcolm Island. She didn't have visible injuries, but "it will not be a surprise if it is found that she died from blunt force trauma resulting from being hit by a boat," according to the Marine Education and Research Society. It adds that "the tragedy might lead to more awareness, from who to call [in case of a marine mammal death], to whatever conclusions can be made about the cause of her death." The Noyo Center warns the public not to approach a dead marine mammal but to contact the proper authorities. Apart from human interaction, unusual mortality events are often attributed to infectious disease and biotoxins, according to NOAA Fisheries. (Read more whales stories.)