Researchers have shown that levels of anisakid worms -- a common marine parasite -- rose in two salmon species in the Gulf of Alaska and Bristol Bay over a 42-year period. The team discovered this by studying salmon caught, killed and canned from 1979 to 2021.
Since anisakid worms have a complex life cycle involving multiple types of hosts, the researchers interpret their rising numbers as a potential sign of ecosystem recovery, possibly driven by rising numbers of marine mammals thanks to the 1972 Marine Mammal Protection Act. Alaskan waters are a critical fishery for salmon. Complex marine food webs underlie and sustain this fishery, and scientists want to know how climate change is reshaping them. But finding samples from the past isn't easy. "We have to really open our minds and get creative about what can act as an ecological data source," said Natalie Mastick, currently a postdoctoral researcher at the Peabody Museum of Natural History at Yale Universit