Growing Water Classifications

Under the CSSP guidelines, each shellfish growing area must undergo a comprehensive survey before it can be approved for harvesting. Resurveys are conducted regularly to determine if sanitary conditions have undergone significant change. Change in pollution source conditions is evaluated in all approved growing areas annually by means of a formal reappraisal conducted both in the office and in the field. A complete re-evaluation of each approved area is conducted at least once every three years. This evaluation includes the field review of pollution sources, analysis of at least the last fifteen water samples from each key station and other field works as deemed necessary to determine the appropriate classification for the area.

Unclassified areas are regions where the sanitary suitability for harvesting is undetermined and therefore not approved for shellfish harvesting at present. Under the CSSP guidelines, un-surveyed areas are closed but would need to be surveyed and classified prior to their approval for commercial harvesting.

Three general classifications are used in the Canadian Shellfish Sanitation Program. Each classification is related to the bacteriological quality of the growing water, the actual and potential sources of pollution and, to some extent, the shellfish resource utilization of the area. [CSSP Manual of Operations Chap. 2.3; 1995]

The classifications are as follows:

(note this is provided as information only please be sure to check the most recent on-line version of the CSSP manual here)

Approved

Shellfish growing areas may be designated as "Approved" if the following conditions are met:

1. the area is not contaminated with faecal material, poisonous or deleterious substances or marine biotoxins to the extent that consumption of the shellfish might be hazardous; and

2. the median or geometric mean faecal coliform Most Probable Number (MPN) of the water does not exceed 14/100 ml, and not more than 10% of the samples exceed a faecal coliform MPN of 42/100 ml, for a five-tube decimal dilution test.

[CSSP Manual of Operations Chap. 2.3.1; 1995]

The sanitary survey indicates that sewage from adjacent communities would not reach this area in such concentration as to constitute a public health hazard, even under conditions which reflect the worst pollution conditions. Any evidence of potential pollution sources is sufficient to exclude the growing waters from the Approved category.

Conditionally Approved

Shellfish growing areas may be designated as "Conditionally Approved" if the following conditions are met:

1. during those times when harvesting is permitted, the area meets all of the requirements of an "Approved" area;

1. conditions which preclude harvesting in areas designated "Conditionally Approved" must be:

   1. easily identified by routine measurement and reporting; and
   2. predictable and/or controllable.

[CSSP Manual of Operations Chap. 2.3.2; 1995]

During shellfish harvesting times, this area has the same sanitary quality as approved areas, however, the quality varies with;

1. the effectiveness of sewage treatment for a community,
2. rainfall or river flow,
3. seasonal changes in sanitary conditions (i.e. tourist or summer cottage activity, vessel traffic, seasonal industrial operation) or some other predictable condition.

During predicted periods of reduced sanitary quality the area is placed into a Closed status.

Closed

Shellfish growing areas are designated as "Closed" under any of the following conditions:

1. the area is contaminated with faecal material, poisonous and deleterious substances to the extent that consumption of the shellfish might be hazardous;
2. the median faecal coliform MPN of the water exceeds 14/100 ml, and/or more than 10% of the samples exceed a faecal coliform MPN of 43/100 ml, for a five-tube decimal dilution test; and/orc) the paralytic shellfish poison (PSP) concentration is = 80 µg/g and/or amnesic shellfish poisoning (ASP) concentration is = 20 µg/g of edible portion of raw shellfish meat, or other neurotoxic shellfish poison is found in detectable levels.

[CSSP Manual of Operations Chap. 2.3.3; 1995]

Direct harvesting from this area is prohibited due to chemical or bacteriological contamination and shellfish can be used only by permit under specified conditions for depuration, relaying, experimental purposes or other approved processing.

Restricted for Controlled Purification

(This is a sub-classification within the Closed area classification)

An area that is Closed, however the following criteria have been met:

• The median or geometric mean faecal coliform MPN of water does not exceed 88/100 ml and not more than 10% of the samples exceed a faecal coliform MPN of 260/100 ml, for a five-tube decimal dilution test.

[CSSP Manual of Operations Chap. 2.3.3.1; 1995]

Areas in which harvesting is allowed for Controlled Purification will be specifically designated according to species-specific initial faecal coliform stock standards and the effectiveness of the purification process. All purification (depuration) takes place in waters which are designated Approved.

Restricted for Relaying

(This is a sub-classification within the Closed area classification)

An area that is Closed, however the following criteria have been met:

• The median faecal coliform MPN of the water exceeds 14/100 ml, and/or more than 10% of the samples exceed a faecal coliform MPN of 43/100 m, for a five-tube decimal dilution test. These areas must not be in a Prohibited area (see below).

[CSSP Manual of Operations Chap. 2.3.3.2; 1995]

The shellfish must be held in Approved area waters for a sufficient time and under adequate environmental conditions to allow purification to occur. This period shall be at least 14 consecutive days when environmental conditions are suitable for purification unless shorter periods are demonstrated to be adequate.

Prohibited

(This is a sub-classification within the Closed area classification)

An area that is Closed, however the following criteria have been met:

Distinct areas or areas within Closed growing areas that are prohibited to shellfish harvesting for any purposes. These areas include:

1. a minimum or 300 m closure in the immediate vicinity of major point source discharges such as sewage and outfalls;
2. within 125 m (minimum) of certain permanent or floating structures which may be the source of contamination. Such structures are defined as follows:

   1. any wharf, dock, platform or floating structure used for vessel moorage; or
   2. including float homes, barges, platforms and vessels used for accommodation, fish processing or any other purposes; and
3. areas where due to the degree of contamination in the growing waters (i.e. waters having excessive concentrations of poisonous or deleterious substances), it may not be possible to adequately depurate or naturally purify the shellfish.

[CSSP Manual of Operations Chap. 2.3.3.3; 1995]

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