1. Risk assessment of water and shellfish quality in Clew Bay Fergal Guilfoyle Terence O’Carroll

2. Why carry out a risk assessment? Problems with current legislation/directives Proactive rather than reactive More than just monitoring required Identifies problem areas Allows potential to improve situation

3. Why Clew Bay? Has a good record in respect of shellfish safety The Clew Bay Marine Forum Ltd. Active CLAMS group Good working relationship with Authorities Good existing sampling programme

4. Shellfish Water Quality Shellfish water quality traditionally assessed by E. coli and Faecal coliforms Main health concern are viruses (Hepatitis A and Norwalk-like viruses) Viruses survive longer in environment and are slower for shellfish to depurate Other potential contaminants, heavy metals, hydrocarbons etc. New methods needed

5. Sources of Information. Shellfish Industry DoCMNR Marine Institute An Post Geodirectory and CSO figures Local Authority (Mayo Co. Co.) Wastewater Treatment Plants Licensed industries. Blue Flag Beaches EPA

8. Level of risk assessed for each main area:

10. Practical Assessment 10 sites selected Mussels and Gigas Oysters at each site Sub Samples tested for E. coli and Bacteriophage Water chemistry also collected at each site and from main rivers

11. Bacteriophage as indicators Bacteriophage may be useful indicator Easy to detect Cheap to test for (?) Present in human sewage Able to show same or better survival characteristics than the pathogens Not pathogenic themselves

12. Preliminary Results 4 months sample results collected Results confirm the level of risk assessed

14. Preliminary Results 4 months sample results collected Results confirm the level of risk assessed What level is safe? -5000 pfu/100g? -2000 pfu/100g? -<30 pfu/100g?

15. Conclusion: Currently farmed shellfish are mainly in ‘low’ risk areas Microbiological & biotoxin contamination main concern for shellfish Human population and treatment most important influence Clew Bay water quality is very good for most part Risk assessment seems to tally with bacteriophage results Thank you