Bathers on a Cornish beach

© Crown copyright 2010

Microbiological monitoring of the marine environment is currently focussed on identifying faecal pollution of bathing waters and shellfish harvesting areas. There are three national programmes covering bathing waters, shellfish waters and shellfish hygiene. Management regimes are in place to protect public health in relation to shellfish, ensuring that contaminated shellfish does not reach the market.

We have assessed microbiological data against standards set within the EU Bathing Waters Directive, the Shellfish Waters Directive and the Shellfish Hygiene Standards within the EU Food Hygiene Regulations. Current standards assess bacterial contamination as indicative of levels of faecal pollution. This serves as a proxy for other agents such as viruses. Limited ability to measure viral loads in the environment and a lack of understanding of the dose-response relationship in humans means that viral standards have yet to be established. Such issues continue to be investigated with a view to developing a viable approach to the management of viruses.

Bathing Waters: In 2007, 96% of bathing waters met at least the ‘imperative’ (compulsory) standard and 76% met the ‘guideline’ (desirable) standard under the EU Bathing Waters Directive. This is similar to the findings in . The 2003 assessment showed that 98% of designated bathing waters met the imperative standard and 74% met the guideline standard. See Figure 4.17 (below) for a regional summary of compliance with the imperative bathing waters standard.

All bacteria concentrations per 100 ml of seawater; Bathing Waters Directive: Imperative standard 10000 total coliforms, 2000 faecal coliforms in 95% of samples; guideline standard 500 total coliforms and 100 faecal coliforms, in 80% of the samples.

Shellfish Waters: In 2007, 40% of sampled shellfish waters met the guideline value under the EU Shellfish Waters Directive (see Figure 4.18 (above) for locations and time series). This value is significantly more stringent than the guideline standard in the Bathing Waters Directive. (Shellfish taken from the more contaminated waters are cleansed prior to sale for human consumption, to reduce bacterial contamination to a safe level.) Charting Progress undertook only a limited assessment so we cannot determine whether any significant change has taken place since then.

Shellfish Hygiene: In 2007, shellfish from 21% of areas could be consumed without treatment, while 78% required some treatment. Less than 1% was prohibited from harvest on the grounds of microbiological contamination. Comparable figures in Charting Progress were 17%, 82% and 1%, respectively.

The levels of compliance reflect significant investment in sewage treatment and infrastructure driven by the Bathing Waters and Shellfish Waters Directives. Water companies plan to spend over £300 million on additional improvements under these Directives over the next five years. Further improvements in microbiological quality will also require measures to reduce the impact of land run-off. This includes reducing misconnections in piping, sustainable drainage systems, and in changes to land management, such as establishing buffer zones excluding grazing animals from the vicinity of water courses. Viruses are also of concern and further work is needed to measure them and establish suitable standards.