"My husband and I have been dipnetting on the Kasilof since 2014. This year we noticed more small fish than usual and all but ~5 of the 35 fish we caught had parasites."

The white spots found in the smelt appear to be tapeworm or nematode larvae. The Centers for Disease Control and Prevention (CDC) recommend cooking fish at about 153 degrees Fahrenheit for 5 minutes or freezing the fish at -4 degrees Fahrenheit for 7 days to kill the larvae before you eat the fish.

Data cited by the B.C. Centre for Disease Control suggests 75 per cent of wild Pacific salmon are infected with the parasite. If fish is to be consumed uncooked, killing the parasites requires it to be frozen at -20 C for at least a week, Young said. Most commercial sushi-grade seafood suppliers freeze at -40 C.