Shellfisheries water quality

Our role 

We provide integrated policy advice, covering issues related to pollution impact, food quality and human health in coastal waters. This advice has secured improved public health protection and satisfies Defra's purpose and objectives.

The main focus of our advice is on the effect of human and animal microbiological 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 industries' products.  

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 water quality scientists have also supported Defra and the EA on past EU infraction proceedings under the European Directives, providing advice on pollution assessment of shellfisheries and implementation of domestic Shellfish Water Protected Areas legislation.  

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.   

Shellfish waters  

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 Protected Areas (England and Wales) 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. 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 former Defra website (now available through the National Archive website).
  • 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 the MAGIC web browser.   

Download Waters

Fishery Orders

We support Defra in its duties in respect of Several and Regulating Orders