Here’s the scenario. You drop by the local fish market and treat yourself to something expensive. Perhaps a piece of halibut or fresh mahi or maybe a swordfish steak. After getting everything ready at home, when you cut the fish into serving sizes, a fat, orange live worm pops out of the meat. What do you do? Are you horrified? Do you take it back and make a scene? Or do you pull out the parasitic worm(s) and keep eating your tasty food?
According to a story on Dailydot. In a recent video that went viral on TikTok, Costco shopper Rachel Lyn caught live worms crawling inside a sealed package of fresh salmon fillets. Costco might not be one of the best places to buy fish, but I bet a lot of you have bought seafood at other stores that are similar.
Costco has also been sued in the past for having worms in their halibut, and Whole Foods has also been sued after a customer found worms in their salmon. Truth be told, though, and you may not want to believe it, a lot of the fish you buy or catch has or had worms in it. Sometimes you see them, sometimes you don’t, but guess what? It’s not abnormal nor that big a deal.
Just so you know, I’m not saying I don’t get mad when I find worms in my fish, but I’m not so mad that I have to throw away the fillets. I’ve noticed that anglers are much more likely than non-anglers to think this way. This is because fishermen who catch food are more in touch with how things really work.
Anisakid nematodes, which are also known as herring worms or cod worms, are the most common type of worms found in fish, like that Costco salmon. Similar worms are routinely found in freshwater species as well. The news story says that 75% of wild Pacific salmon are infected with them, but they’re not just found on the West Coast.
I vividly remember my first cod trip years ago off Rhode Island. I was excited to bring the fresh cod fillets to my wife (at the time) and cook them for her and her grad school roommates. We did great. I was warned, however, that there would be worms in the meat. The charter captain told me it’s rarer to find a cod without worms than with them. He suggested that I soak a paper towel in freshwater and wrap the fillets overnight in the refrigerator. He said this would either get some worms out or at least bring them to the surface of the fillets so I could easily grab them and pull them out slowly. It worked, thank goodness, because if any of the women I was cooking for had seen one of those bright orange wrigglers, I would have been toast.
Salmon is a popular and healthy fish choice. But no one wants to take a bite of their grilled salmon fillet only to discover it contains slimy, wriggling parasitic worms While shocking and off-putting, the reality is that many wild salmon harboring small parasitic worms are still safe to eat if handled and cooked properly
Why Do Salmon Have Worms?
Several species of thin, thread-like parasitic roundworms naturally infect salmon and other fish species Two common types are
-
Anisakis – Also called herring worm or cod worm. Most prevalent in wild Pacific salmon.
-
Pseudoterranova – Similar nematode also found in cod and other fish. More common in Atlantic salmon.
These worms enter salmon when they eat infected copepods or other small crustaceans. They then burrow into the visceral cavity and muscle flesh. Up to 70-90% of wild Pacific salmon may have anisakid worms.
Pests are very rare in farmed salmon because they don’t eat infected wild fish. But wild salmon are extremely prone to picking up worms.
Detecting Worms in Salmon
Thin salmon parasite worms are hard to see and may go unnoticed. A small raised bump or discolored spot on the fillet is often the only sign.
Some clues that may indicate worms in salmon:
-
Visible worms or movement under the skin or when cutting into fillets
-
Black or darkened pin-sized dots on the surface of the raw salmon
-
Tiny holes or tunnels in the flesh
-
Swollen belly cavity when gutting a whole fish
Freezing, brining, or marinating can help draw out or kill hidden worms but manual inspection of the raw salmon is key.
Health Risks of Eating Salmon with Worms
Eating worms sounds unappealing, but consuming salmon with parasites only causes issues if the worms are still alive. Dead, frozen, or adequately cooked worms are digested and harmless.
But ingesting live worms can lead to:
-
Allergic reactions with vomiting, diarrhea, swelling, rashes
-
Stomach or intestinal discomfort as worms may attach to tissues
-
Rarely, fever, abdominal pain if worms penetrate gut lining
So fully cooking salmon to kill any worms is vital. The FDA warns against consuming raw salmon or ikura due to parasite risks. But cooked infected salmon is safe since heat kills the worms.
Cooking and Freezing to Kill Worms
Cooking salmon to an internal temperature of at least 145°F for 15 seconds will destroy any roundworm larvae or eggs, rendering them safe to eat.
Worms can withstand temperatures up to 113°F, so low-temp cooking like sous vide or rare grilling may not suffice. Frying, baking, or poaching helps ensure worms are killed.
Freezing can also destroy parasites. Store salmon at -4°F or below for 7 days to kill worms through freezing damage.
Salting or pickling may immobilize worms but does not reliably kill them. Manual removal of visible worms is recommended.
Safe Handling of Infected Salmon
To safely handle and prepare salmon with worms:
-
Inspect raw fillets and discard any visible worms. Cook remaining flesh thoroughly.
-
Freeze fillets for the FDA recommended times to kill parasites.
-
Avoid cross-contaminating surfaces and utensils used with raw salmon containing worms.
-
Cook to minimum safe internal temperatures. Whole salmon should reach 145°F in the thickest part of the flesh.
-
Wear gloves when handling infected raw salmon to avoid transferring parasites.
-
Discard any infected salmon scraps, especially if worms are visible, rather than using for tartare, ceviche, or other raw preparations.
Avoiding Wormy Salmon
While most wild salmon contain worms, you can take steps to lower risks:
-
Purchase high-quality sushi-grade salmon which has been frozen to FDA standards to kill parasites.
-
Inspect salmon carefully before purchase and avoid fillets with holes, bumps, or discoloration which may indicate worms.
-
Farm-raised salmon have almost no parasite risk since they don’t eat infected prey. But they lack the rich flavor of wild salmon.
-
Canned salmon is cooked during processing which kills any worms.
-
Cut and inspect salmon into smaller portions prior to cooking. Discard any infected sections.
-
Apply pressure while running a sharp fillet knife over raw salmon to reveal parasites.
While not appetizing, worms in salmon pose minimal risks if the fish is handled and cooked properly. Rather than wasting good salmon, take steps to identify and destroy parasites through adequate cooking, freezing, or discarding infected sections. With care, salmon with worms can still provide a healthy and delicious meal.
Wild Fish Have Worms
Strangely enough, people are turned off by worms in fish at the same time that we love “wild caught” and organic meat. I also like organic food, and I often buy more tomatoes and other vegetables at farm stands than at the store. But I know the risk is greater for these veggies to have bugs. Unless you want to eat nothing but tank-raised tilapia or trout, wild fish have “bugs,” too.
Seafood sellers do everything they can to get rid of nematodes in their fish, but sometimes they will still get those little guys. That’s not smart when it comes to lawsuits because a live worm in a fish means it’s fresh and has never been frozen. It’s easy to see why people would think the fish is bad or has been handled badly, but you’ve probably eaten a lot of worms already. Eating fish with worms likely won’t have an adverse effect on you.
Read Next: How to Fry Fish
Are My Sashimi And Raw Fish Safe To Eat? | Talking Point | Full Episode
FAQ
What if I ate a salmon with worms?
How common are worms in salmon?
Do parasites get cooked out of salmon?