With cases of shellfish-related illness on southern Vancouver Island, Island Health says the best way to protect self-harvesters is to not collect shellfish in closed areas.
The advisory comes on the heels of a warning this week from Fisheries and Oceans Canada (DFO) of illegal shellfish harvesting around Nanaimo and the Sunshine Coast.
Almost 3,000 clams were seized by DFO officials between June 13 and 17 and $600 of tickets were issued for harvesting in closed areas of beaches because of contamination.
The health region says toxic algae often increase because of warming ocean water temperatures in the summer.
Toxins can accumulate in affected shellfish that include clams, oysters, whole scallops, mussels, cockles, geoducks, whelks, periwinkles, or the innards of crab.
Island Health says toxins can be in crab flesh if it is boiled before innards are removed and cooking shellfish does not make it safe from toxins.
Although it will reduce disease from bacteria and viruses.
Island Health says symptoms of shellfish poisoning can happen in minutes or up to 24 hours after consumption.
Symptoms in mild cases include tingling, vomiting, diarrhea, headache, dizziness, muscle weakness, disorientation, memory loss, loss of coordination, or difficulty swallowing, and should disappear within several days.
Island Health says in serious cases, seizures, unstable blood pressure, paralysis, difficulty breathing, coma or death may occur.
If you have any of these symptoms after eating shellfish, you are asked to call poison control centre at 1-800-567-8911 and seek immediate medical attention.