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numbers of E. coli in samples of shellfish flesh, harvesting areas are classified as
follows (SEAFISH 2017):
Class A—where bivalve molluscs can be harvested for direct human consumption.
Class B—where bivalve molluscs must be:
1. Purified (cleansed of bacteria through an approved depuration unit).
2. Relayed in an approved Class A relaying area.
3. Heat treated by an approved method before they can be sold for human
consumption.
Class C—where bivalve molluscs must be relayed (for a minimum of 2 months) to
meet Class A or B, or be heat treated.
Prohibited area—area from which bivalve molluscs cannot be harvested for
human consumption.
The classifications are based on the following criteria:
Class A—an area in samples of live bivalve molluscs must not exceed, in 80% of
samples collected during the review period, 230 E. coli per 100 g of flesh and
intravalvular liquid. The remaining 20% of samples must not exceed 700 E. coli
per 100 g of flesh and intervalvular liquid.
Class B—an area where 90% of samples have less than 4600 E. coli per 100 g of
flesh; the remaining 10% of samples must not exceed 46,000 E. coli per 100 g of
flesh.
Class C—an area where molluscs must contain less than 46,000 E. coli per 100 g of
flesh.
Prohibited area—an area where levels are higher than 46,000 E. coli per 100 g of
flesh.
Protection of water resources is another measure to ensure shellfish safety.
Management practices that improve contaminated water source will protect shellfish from contamination. For this, sources of contamination should be placed away
from water bodies. Waste should not be mixed with water. Sewage discharged into
water bodies should be treated and sewage systems should be well designed. Natural
buffers or filters (such as wetlands, mangroves, settling ponds, riparian or littoral
filters) could be created/restored between contaminant sources and at-risk waters.
Such a strategy should include controls over wastewater or bilge dumping from
commercial and recreational vessels in the vicinity of shellfish waters. It is essential
that management efforts between watersheds and/or river basins and coastal zones
are co-ordinated. This will require communication between local, state, and federal
agencies and defining regulatory standards that can achieve both water and shellfish
fishing goals (Rees et al. 2010).
5.5 Shellfish Safety Assurance
numbers of E. coli in samples of shellfish flesh, harvesting areas are classified as
follows (SEAFISH 2017):
Class A—where bivalve molluscs can be harvested for direct human consumption.
Class B—where bivalve molluscs must be:
1. Purified (cleansed of bacteria through an approved depuration unit).
2. Relayed in an approved Class A relaying area.
3. Heat treated by an approved method before they can be sold for human
consumption.
Class C—where bivalve molluscs must be relayed (for a minimum of 2 months) to
meet Class A or B, or be heat treated.
Prohibited area—area from which bivalve molluscs cannot be harvested for
human consumption.
The classifications are based on the following criteria:
Class A—an area in samples of live bivalve molluscs must not exceed, in 80% of
samples collected during the review period, 230 E. coli per 100 g of flesh and
intravalvular liquid. The remaining 20% of samples must not exceed 700 E. coli
per 100 g of flesh and intervalvular liquid.
Class B—an area where 90% of samples have less than 4600 E. coli per 100 g of
flesh; the remaining 10% of samples must not exceed 46,000 E. coli per 100 g of
flesh.
Class C—an area where molluscs must contain less than 46,000 E. coli per 100 g of
flesh.
Prohibited area—an area where levels are higher than 46,000 E. coli per 100 g of
flesh.
Protection of water resources is another measure to ensure shellfish safety.
Management practices that improve contaminated water source will protect shellfish from contamination. For this, sources of contamination should be placed away
from water bodies. Waste should not be mixed with water. Sewage discharged into
water bodies should be treated and sewage systems should be well designed. Natural
buffers or filters (such as wetlands, mangroves, settling ponds, riparian or littoral
filters) could be created/restored between contaminant sources and at-risk waters.
Such a strategy should include controls over wastewater or bilge dumping from
commercial and recreational vessels in the vicinity of shellfish waters. It is essential
that management efforts between watersheds and/or river basins and coastal zones
are co-ordinated. This will require communication between local, state, and federal
agencies and defining regulatory standards that can achieve both water and shellfish
fishing goals (Rees et al. 2010).
5.5 Shellfish Safety Assurance