Chuck Seaca rooted through the chest freezer in his Anchorage garage.
"We still have a fair amount of salmon here in the bottom," he said.
He held up a few large sockeye salmon fillets, vacuum sealed in frosty plastic.
"Once I realized I was allergic to the worms in these fish, gave away a bunch more," he said. "I'm feeling sad just looking at 'em."
About a year ago, Seaca had a violent reaction after eating the salmon he and his family had caught dipnetting.
"I got pretty sick, which mostly just looked like I was puking for like six hours, and my wife and daughter were totally fine, and they had eaten the same fish," he said.
When it kept happening, he went to an allergist. After testing, doctors broke the news that he was allergic to a parasitic roundworm called Anisakis, commonly found in salmon. They told him he would also have to stop eating all seafood, including any sea mammals like walrus.
"It felt like a gut punch," he said. "It feels like a pretty fundamental part of being who I am, and also being an Alaskan, is fishing and eating fish."
Seaca grew up fishing with his family in Bethel. Last summer, his young daughter helped with dipnetting for the first time. Her role was running up to the adults to bring them a fish bat when they needed it to bonk a fish.
Now, he and his wife and their daughter aren't eating that salmon. They gave most of what they caught last summer away.
Seaca's story is an example of something head Alaska epidemiologist Joe McLaughlin said is a growing concern in the state.
"Most seafood remains safe when it's properly prepared, and seafood allergic reactions remain relatively uncommon, although it does appear though the incidence is increasing," he said.
McLaughlin said epidemiologists don't know how many people in Alaska are allergic to the Anisakis worm. Other symptoms of the allergy include hives, difficulty breathing and gastrointestinal distress, and symptoms can be milder than what Seaca experienced.
McLaughlin said the prevalence of the parasite seems to be increasing, including in Alaska fish, but scientists don't know exactly why. He said climate change is one likely factor, as ocean temperatures rise and the availability of nutrients shift. He said the parasite's ideal hosts are marine mammals like whales and seals, so another likely factor is rebounding populations of some marine mammals since the state began protecting them in the 1970s.
"Anything that increases the population of marine mammals and fish that are part of the life cycle, you're going to get more Anisakis worms," McLaughlin said.
It's important to remember that these parasitic worms are part of the normal marine ecosystem, he said. But if Alaskans eat fish, he said they should still protect themselves from the parasites. That means cooking fish well or freezing it sufficiently before eating it raw. Fish should be frozen at minus 4 or colder for seven days or at minus 31 or colder, until solid.
"It's good to eviscerate or clean the fish as soon as possible after they're caught," McLaughlin said.
That can reduce how many worms enter the flesh of the fish.
Much of the research on the Anisakis allergy takes place in Japan, which has a fish-forward culture like Alaska.
Dr. Makoto Nojo, a researcher based in Tokyo, said the allergy is very common in Japan and is distinct from Anisakiasis, which is the parasitic infection from Anisakis. Some data show as many as one in five anaphylaxis reactions in Japan are due to the worm.
"It's both becoming more common, and the diagnosis techniques are advancing as well," he said.
Like Alaskans, Japanese people eat a lot of fish. Much of that is raw, but unlike in the United States, Japan doesn't have laws that require restaurants to freeze fish before serving it raw, and increased exposure to live parasites increases the risk of developing allergies. Nojo said the Anisakis allergy is often misdiagnosed, partly because there can be a delay in the allergic reaction.
He said people with the allergic reaction fall into two groups. Most people react to live baby worms, which is only a problem if someone eats raw seafood that has not been sufficiently frozen. But a minority, like Chuck Seaca, have what Nojo calls "classical Anisakis allergy," an allergy to the protein itself, which isn't destroyed through cooking or freezing.
"Classical Anisakis allergy is almost (the) same (as a) normal food allergy, so using immunotherapy is very critical and useful," he said.
Seaca said he advocated for treatment and eventually convinced his insurance company to cover immunotherapy. In March, he started a once-a-month allergy shot likely to reduce his allergic response. After nine months to a year of treatment, he said, his allergist will test whether he can try salmon again, though he will need a monthly injection indefinitely.
Seaca said he really hopes the treatment works.
"Oh, the first thing I will want to eat, I mean, if I can get my hands on some, I'll have some salmon from Bethel," he said.
That won't be for many months, but he said this summer he's still planning to dipnet on the Kenai River with his wife and daughter. He said fishing feels very meaningful, even if they end up giving away all the salmon they catch.
Translation from Japanese was provided by D'mitri Moore. You can find out more about how to harvest and prepare fish safely here.
