Shellfisheries water quality
We provide integrated policy advice, covering issues related to
food quality and pollution impacts in coastal waters. This advice
has secured improved public health protection and satisfies Defra's core objectives:
- protection of the environment
- policy integration
- support for rural economies
- promotion of a safe, sustainable food chain
- safeguarding environmental quality.
The main focus of our advice is on the microbiological affects
of human and animal pollution on commercially harvested bivalve
molluscs (e.g. mussels, oysters, clams).
We work with the Environment Agency
(EA) to ensure that improvement schemes for sewage pipeline
discharges are developed and effectively targeted so that pollution
in shellfisheries is reduced. This means that humans are less
likely to fall ill; it also enhances the value of shellfish
The work done in this area is enhanced by other work funded
by the Food Standards Agency
(for example, the classification of
shellfish harvesting areas).
Our Shellfish Hygiene (Statutory) Water Quality team has
also supported Defra and the EA on past EU infraction proceedings
Shellfish Waters Directive, providing advice on pollution
assessment of shellfisheries.
We maintain an integrated shellfish-hygiene database and
mapping tool. This includes a discharge database containing records
of current and historic pipeline discharges. It offers unique
information and a strategic tool to underpin impact assessments and
policy decisions in the marine environment.
Over recent decades, sewage discharge improvement schemes have
contributed to less microbiological contamination in designated
shellfish waters. However, a number of these schemes have failed to
comply with the microbial standard specified in the
Shellfish Waters Directive. This results in both the industry
and public health being compromised.
Our team works with Defra and the EA, helping them to
deliver their commitments for the designation of waters under the
Shellfish Waters Directive. We are currently developing
classification and monitoring regimes for shellfish waters as
protected areas under EC Water Framework Directive after the
Shellfish Waters Directive is repealed in December 2013. The
shellfish waters designation policy for England and Wales has
ensured that, where new and sustainable bivalve shellfish
harvesting areas are identified, new waters can be designated
(which confers protection).
- The schedule of designated English shellfish waters can be
found on the
- Maps of the designated English shellfish waters can be viewed or
downloaded from this site.
- GIS layers of designated shellfish waters can be accessed using
We support Defra in its duties in respect of Several and Regulating
Orders. Fishery orders and associated maps in England can
be viewed or downloaded from
We undertake and contribute to research on the microbiological
quality of shellfish and shellfish water quality. This research
includes virus inactivation and sewerage-treatment processes, land
run-off and the effect of organic wastes on shellfisheries,
pollution-tracing techniques, and relationships between faecal
indicator bacteria in shellfish flesh and overlying waters.
Research projects include:
Investigation projects include: