NEWSLETTER
ST. LAWRENCE VISION 2000
VOLUME 10 – ISSUE 9 – MARCH 2000
Preceding issues

	SUMMARY
	Monitoring poisonings linked to the consumption of shellfish from the St. Lawrence
	Indicators that informed us about the state of the St. Lawrence River
	ZIP Chronicle
	News in brief

Le Fleuve is published jointly by St. Lawrence Vision 2000 partners.

Co-ordination
Raymonde Goupil, Clément Dugas and Suzanne Bourget

Text
Gaétane Tardif, Environmental Consultant

Realization
Françoise Lapointe, Editor, SLV 2000

Translation from French to English
PWGSC–Translation Bureau

This Newsletter is also available in PDF Version.

Gathering shellfish is a traditional activity for many people living along the Estuary and Gulf of St. Lawrence. Despite the existence of programs to monitor toxic algae and shellfish, poisonings linked to the consumption of shellfish are reported every year in Quebec. As part of the Health component of St. Lawrence Vision 2000 (SLV 2000), the public health research unit of the Quebec City hospital "Centre hospitalier universitaire de Québec (CHUQ)" has implemented a project to detect cases of poisoning and reduce the health risks for those eating shellfish.

Shellfish are harvested along both shores of the St. Lawrence, beginning near Île aux Coudres on the north shore and Saint-Roch-des-Aulnaies on the south shore, as well as in Chaleur Bay and the Magdalen Islands (PDF map). Because the activity is unregulated, it is difficult to provide an accurate picture of the number of people involved or the most popular areas. However, in the Baie-Comeau region alone, it is estimated that more than a thousand people engage in shellfish gathering.

(See summary of the report (PDF format) Analysis of chemical and microbiological risks related to the consumption of shellfish harvested in the region of Baie-Comeau.)

You don’t harvest shellfish just anywhere!

Today, areas where people can gather shellfish that are fit for consumption are very rare. For example, in the summer of 1999, harvesting was prohibited in 439 of the approximately 525 shellfish areas surveyed in Quebec, while 56 areas were open and another 20 were open under certain conditions.

(Information on shellfish harvesting areas.) Hyperlink at the bottom of the page. Information from Fisheries and Oceans Canada.

This situation is largely attributable to bacteriological contamination of the waters of the Estuary and the Gulf. It is also the result of the presence of toxic microscopic algae that appear in certain areas of the St. Lawrence between June and September. Shellfish filter and accumulate these toxins, thus becoming unfit for consumption.

Red tide in the St. Lawrence River

Alexandrium tamarense, a microscopic toxic alga
On occasion, toxic algae concentrations become high enough to turn the water red.

A well-established monitoring system

Environment Canada is responsible for assessing the bacteriological quality of the waters of the St. Lawrence. On the basis of its recommendations, the federal Department of Fisheries and Oceans (DFO) classifies shellfish areas as open, conditionally open or closed.

	Various shellfish species Photos : Fisheries and Oceans Canada

In the areas classified as open or conditionally open, three agencies are responsible for monitoring marine toxins in algae and shellfish. The Quebec Department of Agriculture, Fisheries and Food (ministère de l'Agriculture, des Pêcheries et de l'Alimentation du Québec – MAPAQ ) is responsible for toxicological analysis of shellfish handled in processing plants and businesses in Quebec. The Canadian Food Inspection Agency (CFIA) monitors toxic shellfish in Canadian waters and in processing plants that sell their products outside the province. Finally, DFO’s Maurice Lamontagne Institute uses a network of coastal stations to monitor the natural appearance of toxic algae in the waters of the St. Lawrence.

When marine toxins are detected by the CFIA, DFO immediately prohibits harvesting in the shellfish area(s) concerned. However, despite all the measures taken to ensure the safety of marine products, shellfish poisonings are reported every year.

(Description of the Shellfish Water Quality Protection Program. See below.)

Some disturbing illnesses

The most common type of poisoning resulting from the consumption of contaminated shellfish from the Estuary and Gulf of St. Lawrence is paralytic shellfish poisoning (PSP). Its primary victims are those who eat mussels and softshell clams. The symptoms of PSP include tingling or numbness in various parts of the body, headaches, nausea, dizziness, loss of coordination and general weakness. In cases of fatal poisoning, death occurs as a result of respiratory failure.

There is no antidote to the toxins responsible for this form of poisoning. In addition, while PSP is the primary threat, other types of poisoning associated with the consumption of shellfish from the St. Lawrence pose potential threats to public health, including amnesic shellfish poisoning (ASP) and diarrhetic shellfish poisoning (DSP).

Since 1880, the St. Lawrence has had the highest incidence of PSP in Canada, with more than 215 reported cases and 25 deaths.

Greater participation by the health network

A study conducted by the CHUQ Public Health Research Unit in 1999 indicated that there is no tool currently in existence that can be used for accurately recording and identifying all cases of marine toxin-induced poisoning in Quebec. While poisonings linked to shellfish consumption are among the diseases that physicians and laboratories are required to report, some cases are apparently not reported. This may be because of a low detection rate on the part of physicians, who are not always familiar with the symptoms produced by shellfish poisonings. Cases of shellfish poisoning may also be confused with other diseases.

As Jean-François Duchesne explains, the public health research unit feels that increased participation by the health network in the existing monitoring system could improve the situation. "This is why we set up a monitoring system in 1999 to record and characterize cases of marine toxin poisoning linked to the consumption of shellfish or other marine organisms collected in the Estuary and Gulf of St. Lawrence. Thanks to this monitoring program, doctors from the emergency units of 18 "sentinel" establishments have participated in awareness sessions designed to help them recognize cases of poisoning. Active monitoring could also permit earlier detection of the effects of new and as yet unknown toxins." All the other hospitals and CLSCs of the regions covered by the project (Quebec City, the Lower St. Lawrence, the North Shore and the Gaspé) have been invited to participate in this monitoring program as well.

As a result, poisonings linked to shellfish or other marine products will be reported rapidly to the regional public health branches, which can then contact the victim to obtain information on a number of factors, including the source of the products (where they were harvested or purchased), the number of persons known to have eaten them, etc. This information will permit an improved response on the part of MAPAQ and the CFIA.

"The contacts established between the health network and the different government agencies responsible for monitoring marine toxins will make it possible to improve the efficiency of the response to a single poisoning or even an outbreak, and thus reduce further risks to the public from the consumption of contaminated shellfish or other marine products," Duchesne noted. "In addition, if we find that the public health problems associated with the consumption of contaminated shellfish are greater than originally believed, corrective measures will be proposed to the agencies responsible for environmental monitoring of toxic algae and shellfish."

For information:

Jean-François Duchesne
Research Officer
Public Health Research Unit, CHUQ
2400 Estimauville
Beauport, QC G1E 7G9
Telephone: (418) 666-7000, extension 205
Fax: (418) 666-2776
E-mail: JFDuchesne@cspq.qc.ca

Source:

DUCHESNE, J.-F., T. TREMBLAY, M. RHAINDS and É. DEWAILLY. 1999. Présence des toxines marines dans les estuaires et le golfe du Saint-Laurent et implications pour la santé humaine. Unité de recherche en santé publique du Centre hospitalier universitaire de Québec, 41 p.

Information on Fisheries and Oceans Canada shellfish harvesting areas:

From Île aux Coudres to Baie-Trinité:
1-800-463-8558

From Saint-Roch-des-Aulnaies to Cap-Gaspé:
1-800-463-0607

From Baie-Trinité to Blanc-Sablon:
1-800-463-1736

From Cap-Gaspé to the Matapédia River:
1-800-463-4204

Magdalen Islands:
1-418-986-3882

(This poster identifies a sector close to shellfish gathering.)

(Back)

Information on Environment Canada’s Shellfish Water Quality Protection Program:

Jacques Sénéchal
Environmental Protection Branch
Aquatic Environment Protection
St. Lawrence Centre
Telephone: (514) 283-0190
Fax: (514) 283-4423

Shellfish Water Quality Protection Program

A wide selection of seafood delicacies is one of the great attractions of Canada's maritime regions. Contamination from many sources including human and industrial waste pose a threat to Quebec’s shellfish resources. This is a matter of increasing concern among health and environmental agencies, the shellfish aquaculture industry and consumers alike.

Through the Shellfish Water Quality Protection Program, Environment Canada fulfills its responsibility for monitoring bacterial water quality in shellfish areas. The surveys conducted under this program require a substantial commitment of effort and resources in order to carefully assess the nearly 25,000 km of Atlantic coastline. Water quality surveys are used to classify coastal waters with respect to their suitability for shellfish harvesting activities. They involve analysing the sanitary and bacteriological water quality conditions in the area.

The Shellfish Water Quality Protection Program also promotes pollution prevention and the remediation and restoration of shellfish harvesting areas. The program’s efforts to eliminate and control pollution sources help to protect the health of both the shellfish industry and the marine environment, and enable health officials to open more shoreline areas to shellfish harvesting. (Back)