Shellfish Water Classification Program

The purpose of the sanitary monitoring is to find and evaluate all sources of sanitary pollution that could affect shellfish harvest waters.

Water quality surveys have two main components:

• sanitary pollution source identification and assessment
• bacteriological water quality monitoring and analysis

The results of water quality surveys are the basis for recommending and verifying the classification of an area in terms of suitability for shellfish harvest.

The classification categories are:

• approved
• conditionally approved
• restricted
• conditionally restricted
• prohibited

The Shellfish Water Classification Program supports the delivery of the Canadian Shellfish Sanitation Program (CSSP), which protects the public from eating contaminated shellfish by controlling the harvest of bivalve molluscan shellfish within Canada.

For more information on shellfish harvest area surveys and classification, please refer to the Canadian Shellfish Sanitation Program Manual.

Bivalve molluscs, such as clams, mussels and oysters, feed by filtering seawater for food particles, such as microscopic algae. However, the water they ingest can also include harmful bacteria and viruses.

The Canadian Shellfish Sanitation Program uses the concentration of fecal coliforms as a simple indicator of bacteriological water quality and shellfish food safety.

Fecal coliforms are organisms used to indicate the presence of fecal matter such as sewage. If water contains elevated concentrations of fecal coliforms, shellfish are likely to be contaminated and therefore unsafe to eat.

The Shellfish Water Classification Program does not test shellfish or shellfish harvest waters for chemicals or biotoxins. Such contaminants may be evaluated by other CSSP partners, in consultation with Health Canada (HC).

Examples of sanitary pollution sources include:

• municipal sewage discharges
• on-site septic systems
• sewage discharges from boats
• agricultural runoff and presence of wildlife
• stormwater from polluted areas

Adverse weather events

The Shellfish Water Classification Program monitors meteorological conditions such as actual and forecasted rainfall, reports of river levels and flooding. The impact of adverse weather events varies by location and with prevailing conditions. Where shellfish harvest area water quality may be negatively impacted, the program:

• may issue public warnings through Canadian Shellfish Sanitation Program (CSSP) partners and
• will recommend closure of shellfish harvest areas if there is reason to believe that sanitary conditions have degraded to the point where accepted water quality standards of the CSSP have been exceeded.

Areas placed under emergency closure remain in closed status for a minimum of 7 days (CSSP manual, Sec B – Shellfish harvest areas, 6.2 Emergency events).

Emergency response

The Shellfish Water Classification Program (SWCP) monitors environmental emergencies notifications from the National Environmental Emergencies Centre (NEEC) that may affect shellfish harvesting areas such as sewage and hydrocarbon spills. The program gathers and shares all relevant information with Canadian Shellfish Sanitation Program (CSSP) partners for assessment and response on a case-by-case basis. SWCP is responsible for assessing spills of sewage to the marine environment and will recommend emergency closure of shellfish harvest areas if they are deemed to pose an unacceptable risk for human consumption.

Areas placed under emergency closure remain in closed status for a minimum of 7 days (CSSP manual, Sec B – Shellfish harvest areas, 6.2 Emergency events).

Wastewater assessments

The Shellfish Water Classification Program (SWCP) uses advanced wastewater modelling techniques to determine the probable extent of water quality impacts on shellfish harvest areas due to wastewater infrastructure. Local meteorological and hydrographic conditions are incorporated into the model in addition to the normal function of the wastewater system and the most likely failure scenarios. Wastewater modelling is one of the tools that the SWCP uses when providing a recommendation for shellfish area classification including conditionally managed areas based on the performance of a wastewater treatment plant and/or collection system (CSSP manual, Sec B – Shellfish harvest areas, 6.1 Conditional management of shellfish harvest areas).

For more information on Emergency events that may impact shellfish harvest areas, please refer to the Canadian Shellfish Sanitation Program Manual, section 6.2 Emergency events.

• shellfish harvest area closures
• danger of illegal harvesting
• weather-related emergency closures
• report a marine pollution incident
• marine biotoxins
• marine bacteriological water quality data
• geospatial boundaries of classified harvest areas

Shellfish Water Classification Program
Environment and Climate Change Canada
Science and Technology Branch
335 River Road,
Ottawa, Ontario K1V 1C7
ec.msqeinformation-wqmsinformation.ec@canada.ca