Shellfish harvest shut down

YARMOUTH — Just about the entire shoreline area of St. Marys Bay and much of the Annapolis Basin is now closed to bivalve shellfish harvesting because of dangerous biotoxin levels.

All bivalve shellfish — those with two shells, including clams, mussels, oysters and scallops — except scallops are affected by the closures, announced Friday by the Department of Fisheries and Oceans.

St. Marys Bay is closed from the southwestern outer edge of Brier Island across to a point near Meteghan River on the Nova Scotia mainland.

The Annapolis Basin and Digby Gut, the narrow passage separating the basin from the Bay of Fundy, are also closed to harvesting.

Other areas around the province also remain closed to bivalve shellfish harvesting.

Toxins known to cause paralytic shellfish poisoning, or PSP, are produced by algae. The problem often occurs when water temperatures rise, the DFO said in a news release.

When the water warms up, more algae bloom.

Clams and other members of the bivalve family are filter feeders, taking water in and expelling it again to trap algae, one of their food sources, said DFO.

Toxins can accumulate over time in the shellfish.

Biotoxins are retained by clams and mussels but only the viscera portion of the scallop is known to retain the toxins, said DFO.

The federal department recommended people consume only scallop meat to be safe.

Eating contaminated shellfish can cause serious harm and cooking does not kill the toxins, the DFO release said.

The department said crab, lobster and shrimp are not affected by this type of toxin.

The Canadian Food Inspection Agency monitors water quality and toxin levels in shellfish.

Federal fisheries officers regularly check for compliance among commercial harvesters, ensuring that proper documentation accompanies commercially harvested shellfish to confirm it has been harvested legally from an open harvesting area and has been properly inspected.

Bivalve harvesting areas are also closed periodically because of sewage contamination or unsafe dioxin levels in some areas, said DFO.

( bmedel@herald.ca)