Allison Little, a middle school assistant principal from Anchorage, has been fishing on the Kasilof River her entire adult life, so she’s used to seeing wormy parasites coiled up in fish on occasion. But last year, as she cleaned her dipnet catch, the worm situation edged into horror movie territory.
“There were so many in this one fish, I wasn’t quite sure what I was looking at,” she said. “I put salt on the fillet and they just started coming out everywhere. This was enough where I actually disposed of it.”
Lately, everybody’s got a gross-out story — wormy restaurant ceviche, live worms in grocery store fillets, backyard barbecues derailed by too many cooked worms coming off the grill. White “sushi worms” — in this case, species of nematodes in the family Anisakidae — are part of life in a place where filling freezers with fish is a cultural, economic and nutritional mainstay. But, in the last few years, fishermen, fish sellers, diners, chefs, scientists and home cooks say they are seeing more worms than they’re used to. It turns out, according to a couple of recent studies done by University of Washington researchers, their observations are right on.
Worms are on the rise. Anisakis worms in all saltwater fish and some cephalopods like squid increased 283-fold from 1978 to 2015, according to a 2020 study analyzing hundreds of papers.
“What we saw was an increase from an average of less than one worm per 100 fish — to more than one worm in every fish,” said Chelsea Wood, the Seattle-based parasite ecologist who oversaw the study.