343 Sei Whales Killed By Toxic Algae In Chile; Domoic Acid Found In Salmon, Squid, Anchovy Tissue
They didn’t think much of the first dead whale. Dwarfed by the rugged cliffs of Patagonia’s high green fjords, the team of biologists had sailed into a gulf off the Pacific Ocean searching for the ocean’s smaller animals, the marine invertebrates they were there to inventory. That night, while hunting for an anchorage in a narrow bay, the team spotted a large, dead whale floating on the water’s surface. But for the biologists, death—even of such an enormous animal—didn’t seem so unusual. Not so unusual, that is, until they found the second whale, lying on the beach. And a third. And a fourth. In all, they found seven in that bay alone. Over the next day, they counted a total of 25 dead whales in the fjord.
As the team of five researchers from Chile’s Huinay Scientific Field Station sailed south across the Golfo de Penas, the dead were there, too: 200 kilometers away, they found four more whales on the beaches of the exposed, outer coast. At one point, someone’s dog rolled in one of the corpses. The scent of dead whale hung in the boat for weeks. “Everybody was clear about it—this is not normal,” says Vreni Häussermann, director of Huinay station and the leader of the group that made the discovery in April 2015. Häussermann and her team found themselves drawn into a whodunit worthy of a detective show: they’d become accidental witnesses to a mass killing. But what had caused it, and just how many had fallen victim?
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Kudela’s lab was sampling algae in Monterey Bay, California, in April 2015—just before the Huinay team discovered the dead whales—when he began noticing rising levels of algal toxins. “We didn’t think it would be that large,” he says. “We happened to be in just the right spot and saw the toxins starting to show up. From there it just kept going.” By the end of the summer, the bloom had spread from Santa Barbara in Southern California to Alaska’s Aleutian Islands. The bloom broke all the records: it was the largest, the longest lasting, and the most toxic researchers had ever seen.
“There was literally these layers where it looked like straw or something, thick with all these cells,” Kudela says. There were a mix of algal species in the bloom, but it was dominated by Pseudo-nitzschia. In the lab, healthy Pseudo-nitzschia can form chains of 20 to 30 of their golden-brown, needle-shaped cells; according to Kudela, wild chains in the 2015 bloom were 100 to 300 cells long. As the toxin progressed through the ecosystem, Kudela’s lab found it everywhere they looked. The prevailing idea was that after small fish such as anchovies, ate the algal cells, the water-soluble toxin would reside only in their stomachs until it was excreted, usually within 24 hours. But during the 2015 bloom, Kudela’s lab could find domoic acid integrated into anchovy muscle, brains, and gills. At local fish markets, they found it in salmon tissue and in squid, neither of which consume phytoplankton directly.
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https://www.hakaimagazine.com/features/death-killer-algae/