Dead fish were in every single place, staining the beach near the town and increasing to the encircling coast. The sheer magnitude of the herring extinction in October 2021, when a whole bunch, perhaps 1000’s, of herring washed up is what stuck within the minds of the people of Kotzebue, Alaska. Fish were “literally on all of the beaches,” says Bob Schaeffer, a fisherman and elder of the Qikiqtaġruŋmiut tribe.
Despite the dramatic death, there was no obvious perpetrator. “We do not know what caused it,” says Alex Whiting, director of the environmental program on the Native Village of Kotzebue. He wonders if the extinction was a symptom of an issue he had been keeping track of for the past 15 years: blooms of toxic blue-green algae, sometimes called blue-green algae, which are becoming increasingly noticeable within the waters around this distant Alaskan town.
Kotzebue is situated about 40 kilometers north of the Arctic Circle on the west coast of Alaska. Before the Russian explorer Otto von Kotzebue attached his name to the place within the nineteenth century, the region was called Qikiqtaġruk, which suggests “a spot that is sort of an island”. On the one hand, the settlement, 2 km long, borders the Kotzebue Strait, a branch of the Chukchi Sea, and on the opposite, a lagoon. Airplanes, boats and four-wheelers are the predominant technique of transport. The only road out of town simply circles the lagoon before returning.
Downtown, the Alaska Commercial Company sells foods popular with under 48s – from cereals to apples and two-bite cookies – however the ocean is a real food market for a lot of city dwellers. Alaska residents, who make up about three-quarters of Kotzebue’s population, pull a whole bunch of kilos of food from the ocean every yr.
“We’re ocean people,” Schaeffer tells me. The two of us are crammed into the tiny cabin of Schaeffer’s fishing boat on a rainy September morning in 2022. We are heading towards the water monitoring device that has been moored in Kotzebue Strait all summer. At the bow, Ajit Subramaniam, a microbial oceanographer at New York’s Columbia University, Whiting, and Schaeffer’s son, Vince, have their noses tucked into upturned collars to guard themselves from the cold rain. We’re all there to assemble summer details about cyanobacteria that may poison the fish Schaeffer and plenty of others rely on.
Huge colonies algae is nothing latest and is usually useful. For example, in spring, increased light and nutrient levels cause phytoplankton to bloom, making a microbial soup that feeds fish and invertebrates. But unlike many types of algae, cyanobacteria could be dangerous. Some species can produce cyanotoxins that cause liver or neurological damage and possibly even cancer in humans and other animals.
Many communities have fallen victim to cyanobacteria. Although many cyanobacteria can survive in marine environments, freshwater blooms are inclined to attract more attention, and their effects can spread to brackish environments as streams and rivers carry them to the ocean. In East Africa, for instance, massive fish kills are blamed on blooms in Lake Victoria. People can suffer too: in an extreme case in 1996, 26 patients died after being treated at a Brazilian hemodialysis station, and an investigation found cyanotoxins within the water supplied by the clinic. More often, those exposed have a fever, headache or vomiting.
