Publication Abstract

Microbiological monitoring of bivalve mollusc harvesting areas in England and Wales: rationale and approach.

Microbiological monitoring of bivalve mollusc harvesting areas in England and Wales: rationale and approach.

A.D. Younger, R.J. Lee and D.N. Lees

The coastline of England and Wales is impacted by numerous continuous and intermittent sewage discharges and many of these are in the direct vicinity of shellfisheries. It cannot always be predicted when intermittent discharges will operate. Furthermore, due to a lack of discharge operational monitoring and recording in some cases, it is not always known when intermittent discharges have operated. Both sewage and agricultural inputs to river systems are also thought to significantly impact on a number of coastal and estuarine shellfisheries. Systematic microbiological monitoring to determine the extent of faecal contamination (using E. cob) of bivalve harvesting areas in England and Wales was established during 1992 in the period immediately preceding the implementation of the Shellfish Hygiene Directive (91/492/EEC). A number of factors contribute to the observed variation in E. coli concentrations within shellfish. These factors include spatial variation across beds; temporal variation due to environmental variables; sampling and transport method; and shellfish test method. Procedures have been established to minimise such variability and, where this has not been possible, to allow for the known causes of fluctuations in the assessment of data. The determination of the number and position of monitoring points has always been based on a risk assessment procedure and this is described. This risk assessment has been undertaken using a Geographic Information System (GIS) to combine information on the location and extent of the shellfisheries with data on the potentially impacting sources of contamination. The GIS is also used in the ongoing management of the monitoring programme, to assist assessment of the results and in production of maps for use by the local authorities with enforcement responsibility.

Reference:

A.D. Younger, R.J. Lee and D.N. Lees. 2003. Microbiological monitoring of bivalve mollusc harvesting areas in England and Wales: rationale and approach. Proceedings of the 4th International Conference on Molluscan Shellfish Safety, Santiago de Compostela, Spain. June 4-8. 2002: 265-277pp

A.D. Younger*, R.J. Lee* and D.N. Lees*

Proceedings of the 4th International Conference on Molluscan Shellfish Safety, Santiago de Compostela, Spain. June 4-8. 2002: 265-277pp