Over the past two months 30 dead whales have washed up along the Alaskan coastline and no one seems to know why.
Over the past two months, 30 dead whales have washed up along the Alaskan coastline, with six more bodies appearing farther south in British Columbia. Although not quite as viscerally horrifying (to most) as the time in 2007 when about a dozen mostly right feet washed up on the shores of the Pacific Northwest, these dead whales are still troubling. Worried that such clustered death might point to deeper ecological problems, the National Oceanic and Atmospheric Administration (NOAA) recently declared an unusual mortality event (UME), allowing them to form a taskforce aided by state, federal, tribal, and Canadian researchers to dig into these whale deaths. So far no investigations have yielded a clear cause, and there's no sign that NOAA will figure this out anytime soon.
To keep things in perspective, there have been much larger mass whale deaths around the world in recent years than the one in Alaska. In 2003, 2010, and February of this year, New Zealand saw between 160 and 200 of the great beasts wash ashore (often due to migration mishaps). Still, 30 dead whales are significant for the region, which has traditionally seen a third as many carcasses over the same amount of time in previous years.
Unfortunately, the NOAA doesn't have a great track record of solving UMEs. Since NOAA started declaring and investigating them in 1991, they've only solved 29 out of 61 cases. Their success rate for solving whale deaths is even worse: of the ten UMEs between 1996 and 2015 involving whales, only two of them were ever assigned a probable cause.
In the only two whale cases where NOAA investigations succeeded in establishing causes (a right whale die-off in 1996 on the Florida and Georgia coast and a large whale die-off on the California coast in 2007), both were attributed to detrimental interactions with humans. That fits with wider scientific investigations into whale deaths. A 2012 study found that between 1979 and 2009, 1,762 whales had died in the northwest Atlantic Ocean, 750 of known causes. Of those with identifiable causes of death, 67 percent were due to ship strikes (171) or entanglement in fishing gear (323), with the remainder chalked up to natural causes. Studies have also linked other mass whale beachings and deaths (including those of 100 melon-headed whales over the course of one month in the Loza Lagoon of Madagascar) to manmade sonar, which fries whale communications and drives them out of local environments. Numerous other whale deaths have been credited to toxic spills contaminating food chains.
You'd think, then, that direct human interactions might be the logical site of blame for the Alaskan whale deaths. But Bree Witteveen, a whale expert at the University of Alaska Fairbanks who has been following the story closely, believes otherwise.
"Deaths resulting from entanglement would show obvious signs," Witteveen told VICE. "And [they] are not likely to result in so many carcasses in such a small time frame."
"Sonar," she continued, "may also be a cause. To our knowledge, however, the [most recent] Navy sonar exercises in the Gulf of Alaska were not initiated until nearly three weeks after the carcasses began to be sighted."
NOAA's current lead hypothesis is that a harmful algal bloom triggered the deaths. Known regionally as "red tides," these events are linked to rising temperatures, which allow life-choking microscopic creatures to proliferate, many of which produce toxins consumed directly or indirectly by whales in tight social formations, leading to the potential for mass deaths.
"Some [algal toxins] mimic neurotransmitters in the brain and cause seizures and death of brain tissue," Spencer Fire, an expert on algal blooms and their effects on whale populations at the Florida Institute of Technology, explained to VICE. "Some interfere with normal nerve function and can cause respiratory paralysis. Some cause gastrointestinal problems."
Numerous mass whale deaths have been linked to algal blooms since the late 1980s. One of the most recent killed 22 whales near Florida's Everglades National Park, and necessitated the euthanization of four more, between December 2012 and January 2013. NOAA is worried that we're seeing a troubling rise in the frequency of such blooms.
Conditions are right for algal death in the North Pacific, where sea surface temperatures have risen 5.4 degrees Fahrenheit above their normal levels, triggering an unprecedentedly long and massive red tide from California to Alaska this year. Fire notes that the region is home to two algal toxins as well: domoic acid and saxitoxin. And the fact that so many whales have died off in a similar area in a short amount of time alongside other marine animals (walruses, as well as seabirds such as murres and shearwaters have turned up dead on the coast) could support the theory of poisoning via algal bloom.
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But Fire cautions jumping to conclusions too quickly. Indeed, the lone sample taken from a whale carcass thus far has only cast doubt upon the algal bloom hypothesis. Toxicology on that flesh, explains Witteveen, came back negative for cesium, ruling out a fringe hypothesis that the whales had somehow been killed by continued fallout from the 2011 Fukushima Daiichi nuclear disaster. But it also came back negative for domoic acid and saxitoxin, the region's two algal toxins. That doesn't prove that algal blooms weren't responsible for the whales' deaths, at least partially, considering the test was conducted only on a single whale. But it certainly doesn't bring us anywhere closer to figuring out an answer to this mystery.
Canadian scientists have apparently started a necropsy on two more whales, which may provide us with some answers to the mystery. Yet any results will take months to assemble. It'd help if we had more evidence to work with, but most of the carcasses are floating along a vast and inaccessible coastline, where bears are getting to them before researchers, consuming their scientifically valuable flesh. Officials are hoping that average folks will be able to help them find more dead whales to test, but caution against touching any of them. Until then, we'll have to rely on what little evidence we have in the search for conclusions that may never come in full. In the meantime, we might collectively want to turn some attention toward that massive oceanic algal bloom, because even if it isn't responsible for this tragedy, it does sound like a disaster waiting to happen.