Molluscan bivalve shellfish and the waters in which they grow are routinely monitored for the presence of sewage contamination. Since these shellfish feed by filtering suspended particles from their aquatic environment they can indiscriminately extract and concentrate bacteria and viruses which pose a threat to human health. These organisms can occur naturally in the marine environment or be present as a result of contamination.

In shellfish growing areas which have become contaminated by sewage there may be bacteria and viruses which have the capability of causing disease in humans. These pathogenic agents can result in illness ranging from mild gastroenteritis (stomach ache) to typhoid fever and infectious hepatitis. Although cooking will generally destroy the pathogenic organisms, shellfish are often eaten raw or undercooked, exposing the consumer to potential disease. Testing growing waters or shellfish tissue for specific pathogens is very expensive and difficult since these organisms can easily go undetected due to their low numbers and problems culturing the organisms. As a result regulatory agencies test for indicator organisms rather than actual pathogens.

The indicator organisms currently used by Canadian agencies to determine the sanitary quality of water and molluscan shellfish belong to the coliform group of bacteria. This group is considered a good indicator of sewage pollution as it contains bacteria found primarily in the intestinal tract of warm-blooded animals. Fecal coliforms and the principal member of this group, Escherichia coli (E. coli), are directly associated with the feces of humans and other warm-blooded animals such as domestic and farm animals, land-based wildlife, marine mammals and birds. Although E. coli will not normally cause disease in humans they do meet the requirements of a good indicator organism. Their presence in samples is easy to determine and they are consistently present in large numbers in sewage (6 million/l00 ml). Fecal coliforms are not normally present in sea-water but are able to survive as well as the pathogens and they are unable to multiply in sea-water.

The sanitary water quality of shellfish growing areas in Canada is assessed under the Canadian Shellfish Sanitation Program (CSSP) using national fecal coliform standards for marine water and shellfish tissue. Foremost in the assessment is an evaluation of shoreline sanitary conditions including the identification of all existing and potential pollution sources. A pollution source inventory is kept by routinely conducting shoreline sanitary inspections and surveys.

The CSSP is jointly administered by Fisheries and Oceans Canada (DFO), the Canadian Food Inspection Agency (CFIA) and Environment Canada (EC). The program is based on the Canada/U.S. Shellfish Agreement signed in 1948 to control and improve the sanitary practices found in molluscan bivalve shellfish industries of the two countries. Compliance with protocols and practices outlined in a Manual of Operations under the bilateral Agreement is a prerequisite to across border shipment and marketing of shellfish products.

Under the CSSP, DFO is responsible for formally closing harvesting areas which are contaminated, posting and patrolling closed areas, enforcement activities and the management of marginally contaminated areas which are only approved for harvesting under certain conditions. CFIA is responsible for ensuring and inspecting for the proper handling, storage and processing of shellfish product and monitoring for naturally occurring marine biotoxins (such as paralytic shellfish poisoning or PSP). CFIA is also the designated lead Canadian contact with the U.S. Food and Drug Administration concerning the bilateral Agreement. EC is responsible for monitoring the water quality of growing areas and the classification of these areas with respect to shellfish harvesting based on survey results. This mandate is accomplished under EC's Shellfish Water Quality Protection Program.

Environment Canada has been assessing the sanitary quality of shellfish growing waters on the west coast of Canada on a regular basis since the early 1970's. Monitoring activities increased dramatically in 1988 as a result of the allocation of new resources to the program. Surveys are conducted according to protocols outlined in the CSSP, Manual of Operations, and water quality is assessed in part against the following water quality standard:

• the median or geometric mean fecal coliform Most Probable Number (MPN) does not exceed 14/100 ml and not more than 10% of the samples exceed 43/100 ml in the multiple tube fermentation (MTF) test.

In addition to the bacteriological marine water sampling surveys, growing areas are assessed using hydrographic and dye release studies, shoreline investigations of point and non-point pollution sources, outfall modeling and sewage treatment evaluations. Under the CSSP, previously unsurveyed ( unclassified ) areas must have a comprehensive sanitary survey completed prior to any commercial or recreational harvesting or harvesting by aboriginals for food, cultural and ceremonial use. If the water quality standard is met (based on 15 data points for each representative sampling station) and no point or non-point pollution sources are identified, the area may be classified 'Approved' for harvesting by the Pacific Shellfish Classification Committee ( PSCC ).

The PSCC is chaired by EC and has representatives from: DFO; CFIA; provincial Ministries of Fisheries, Environment Lands and Parks, and Health, as well as ex officio representatives from industry sectors including shellfish growers, processors and depuraters. Following a classification of Approved, areas must undergo an annual sanitary review, which may involve additional sampling if deemed necessary, and a complete re-evaluation every three years. A reduced re-evaluation frequency may apply to remote north coast areas removed from pollution sources.

Almost all of the southern British Columbia (B.C.) coast has now been classified by EC. Large portions of the north and central coast and the Queen Charlotte Islands have only been surveyed for the harvesting of sub-tidal clams (geoducks). B.C. has a coastline of 26,000 km. On the south coast ( from the north end of Vancouver Island and Cape Caution south ) about 3000 square km or 300,000 hectares (ha) have been surveyed for shellfish harvesting and at present about 226,000 ha ( or 75% ) are classified 'Approved'. Of the 74,000 ha classified 'Closed' to harvesting, 55,000 ha are in the Georgia Basin area which includes the most productive intertidal shellfish growing area on the Canadian coast. The south coast closures include large portions of Burrard Inlet, the Fraser River estuary and Boundary Bay, which are closed due to a variety of potential chemical pollution sources from industrial and agricultural activity in addition to bacteriological contamination.

For monitoring purposes, EC has divided the B.C. coast into 34 growing areas which are further sub-divided into 159 sectors. The Georgia Basin includes at least a portion of 29 of the growing areas and there are 1300 ha of the Basin under provincial shellfish tenure, i.e., licensed for commercial harvesting, out of a total of 2100 ha for the whole B.C. coast.

About 300,000 ha have been surveyed on the north and central coast of B.C. The north coast has been classified mainly for commercial harvesting of the subtidal geoduck clam and the central coast for geoducks as well as intertidal clam harvesting by aboriginal groups for commercial and food, cultural and ceremonial use. Of the 300,000 ha surveyed by EC, 6000 ha ( or 2 % ) are Closed to harvesting for sanitary reasons. Large portions of the north and central coast are under an annual harvesting closure for paralytic shellfish poisoning ( PSP ) administered by the Canadian Food Inspection Agency.

The Queen Charlotte Islands ( Haida Gwaii ) are surveyed and classified for geoduck harvesting on Graham and Moresby Islands and the harvesting of razar clams on the north end of Graham Island. Of the 250,000 ha surveyed, 25,000 ha ( or 10 % ) are closed to harvesting for sanitary reasons and PSP closures are imposed most of the year.

Shellfish growing water quality on the west coast of Canada is assessed by EC using a network of approximately 3500 marine and 1900 freshwater sampling stations from which 5000 samples are collected annually for fecal coliform analyses. Salinity measurements are also taken on the marine samples for comparison with precipitation data obtained from EC's Atmospheric Environment Branch. The survey results are used to assess the adequacy of shellfish closure boundaries, to evaluate water quality at new aquaculture and wild harvest sites and to quantify pollution levels at point and non-point sources.

EC survey results are presented to the Pacific Shellfish Classification Committee (PSCC) at biannual meetings to review the data and make recommendations with regard to priority issues, survey needs and sanitary closure action. When necessary, closure action is taken by issuing Closure Orders under the Management of Contaminated Fisheries Regulations of the federal Fisheries Act. As of July 1999 there were 284 Closure Orders under the Fisheries Act encompassing about 105,000 ha on the B.C. coast. Multiple pollution sources account for the largest area closures, followed by sewage out-falls, agriculture/hinterland drainage, boat sewage discharges, urban run-off including septic seepage and pulp mill pollution.

The area of coastline closed to shellfish harvesting has increased substantially since EC began routinely assessing sanitary water quality in the early 1970's. In the Georgia Basin the population has more than doubled in the last 25 years putting enormous stresses on natural habitats and resulting in a deterioration of marine water quality. In 1998 EC embarked on a major ecosystem initiative to focus and coordinate efforts towards a sustainable future for the Georgia Basin. The Georgia Basin Ecosystem Initiative ( GBEI ) is a 5 year action plan to link the actions of governments and other stakeholders to achieve healthy, productive and sustainable ecosystems and communities. The Clean Water Action Plan, a component of GBEI, will address water quality in shellfish growing and harvesting areas with the goal of re-opening 25% of the areas presently under sanitary closure. This will be achieved by partnering with all levels of government including First Nations, industry and communities to develop a long term strategy for improved water quality, habitat remediation and shellfish restoration.

Delivery of the core monitoring requirements under EC's Shellfish Water Quality Protection Program ensures compliance with the CSSP and the Canada/U.S. Shellfish Agreement with regard to public health protection and across-border marketing. In addition to the current efforts and funding under the GBEI, EC has adopted a pro-active approach to prevention and restoration by assuming specific roles providing information to other regulatory agencies as follows:

• through Regional District referral systems, EC assists municipal and regional planning departments by providing information on local shoreline sanitary conditions, shellfish resources and concerns about sewage disposal, storm water control and farm waste management practices.
• through referral systems for the federal Department of Transport, Navigable Waters Protection Act and the provincial Waste Management and Crown Lands Acts, EC comments on siting and waste handling concerns with respect to shoreline installations and floating operations such as aquaculture facilities, logging and fishing camps.
• through the Pacific Shellfish Classification Committee recommendations are made to the provincial Ministry of Environment, Lands and Parks for the designation of water bodies under the new Pleasure and Non-pleasure Craft Sewage Pollution Prevention Regulations in the Canada Shipping Act.

EC reviews and comments on draft provincial Environmental Guidelines for Agriculture.

Environmental Protection Branch
Pollution Prevention & Assessment Division
401 Burrard Street
Vancouver, B.C.
V6C 3S5

e-mail: ShellfishPacific@ec.gc.ca
Phone: (604) 666-2947
Fax: (604) 666-9107