Fish you catch: parasites, histamine, and keeping your catch cold

Cooking fish you caught yourself is one of the best parts of a camping trip. Fish come with risks other foods don't, and the usual kitchen tricks don't always handle them.

1. Anisakis worms

CDC says anisakiasis is most common where raw fish is popular, such as Japan. Japan's national infectious disease institute once estimated about 7,000 cases a year there. Some people feel a tingling during or after eating raw or undercooked fish or squid; CDC says that is the worm moving in the mouth or throat.

Those freezing conditions come from commercial guidance. Many home freezers don't reach or hold -4°F, so for fish you catch, cooking is the reliable option. FDA adds that freezing doesn't kill all harmful germs, which is why the safest route is to cook seafood. Japan's health ministry also advises removing the guts promptly, because the larvae can move from the guts into the flesh after the fish dies, and never eating the guts raw.

2. Scombroid (histamine) poisoning

FDA says fish most commonly involved are tunas and mackerels, plus bluefish, mahi-mahi and amberjacks. When these fish warm up, bacteria produce histamine, and toxic levels can form in less than 6 to 12 hours without ice or refrigeration. FDA specifically warns that a recreational catch lying on a warm dock or beach is prone to it.

• The toxin is not destroyed by freezing, cooking, smoking, curing or canning (FDA).
• Symptoms can appear within minutes to 2 hours of eating (FDA).
• Japan's consumer agency adds a warning sign: if you feel an unusual peppery tingling on your lips or tongue, don't eat the fish.

3. Keep it cold from the moment you land it

• NOAA: bury your catch in ice immediately, or use an ice slush of two parts ice to one part water.
• FDA: carry seafood in a cooler with cold packs or ice; don't leave it out more than 2 hours, or 1 hour above 90°F.
• FDA: if you eat fish caught by family or friends, check local fish advisories.
• Japan's consumer agency: remove gills and guts as early as possible after catching, since the bacteria live there.

At camp (our suggestions)

• Bring more ice than you think you need, and keep the fish cooler separate from drinks so it stays closed.
• Grill, fry or stew your catch rather than serving it raw.
• Never cook a puffer fish you catch. Japan's health ministry warns that amateurs can't reliably identify the species or which parts are safe.