All harvesting of razor clams and other bivalves is closed on North Beach due to unacceptable levels of the biotoxin causing paralytic shellfish poisoning (PSP).
The closure means no harvesting of any bivalves between Wiah Point and Rose Spit, including clams, cockles, mussels, scallops, oysters, and geoduck.
Fisheries and Oceans Canada (DFO) announced the bivalve closure at 3 p.m. Wednesday, July 18. Updates are available on the DFO website.
The closure has no impact on crab harvesting.
Elysha Gordon, co-ordinator of the Canadian shellfish sanitation program, said that while the PSP biotoxin is commonly called “red tide,” the harmful algal blooms that cause it are usually colourless.
However, many islanders have recently seen red-orange blooms of what is most likely Noctiluca scintillans while taking the ferry from Haida Gwaii to Prince Rupert.
“Often when there is an algae bloom there is more than one species blooming at the same time,” Gordon explained.
“It’s kind of deceiving when you see this red-orange colour,” she said, noting that Noctiluca scintillans is not toxic to bivalve shellfish. “Everyone automatically assumes that’s the toxic one.”
As the name implies, eating shellfish contaminated with the PSP biotoxin can cause death by paralysis, usually of the respiratory system.
Gordon said warm ocean temperature is one factor behind the harmful algal blooms that cause PSP, but so are wind, upwelling, salinity and other factors.
In summer, North Beach bivalves are sampled every week for the marine biotoxins causing PSP, domoic acid poisoning, and diarrhetic shellfish poisoning. In winter, they are sampled every other week.
