The Marine Institute sample a range of finfish species landed at major Irish ports on an annual basis, in accordance with the monitoring requirements of various European legislation designed to ensure food safety. During 2002, a total of 38 samples from 20 different species of finfish were collected from five major Irish fishing ports and analysed for total mercury concentration in the edible tissue (Common names and species names are listed in Appendix 3). The concentration of mercury ranged from less than the limit of quantitation (0.03 mg/kg wet weight) to 0.46 mg/kg wet weight with a mean and median of 0.09 and 0.06 mg/kg respectively. These levels are within the maximum limit of 0.50 mg/kg wet weight for mercury in fishery products set by the EU (1 mg/kg for selected species). This survey confirms previous studies, which show that Irish seafood is effectively free from mercury contamination. Selected samples were also analysed for other trace metals and chlorinated hydrocarbons. Overall, the levels of lead and cadmium detected in the edible portion of the fish were low and well within the standard values of 0.20 and 0.05 mg/kg wet weight respectively, set by the EU. There are no internationally agreed standards or guidelines available for the remaining trace metals and chlorinated hydrocarbons in fishery products. Therefore results are compared with the strictest standards or guidance values for fish tissue, which are applied by contracting parties to the OSPAR Convention. The levels of these additional contaminants are well below the strictest values listed.

Major shellfish growing areas were sampled in accordance with the monitoring requirements of Council Directive 79/923/EEC, on the quality required of shellfish waters, and Council Directive 91/492/EEC, laying down the health conditions for the production and placing on the market of live bivalve molluscs. Data for physicochemical parameters in water and trace metal levels and chlorinated hydrocarbon concentrations in shellfish are presented. In 2002, a total of 24 samples from 22 different shellfish sites were analysed for chlorinated hydrocarbons and trace metals, including nickel and silver. The median concentration of mercury in shellfish sampled in 2002 was <0.03 mg/kg wet weight, which is well within the European maximum limit of 0.50 mg/kg wet weight for mercury in bivalve molluscs. The levels of lead and cadmium detected were low, with means of 0.16 and 0.33mg/kg wet weight and maxima of 0.34 and 0.66 mg/kg wet weight respectively, also within the respective European maximum levels of 1.50 and 1 mg/kg wet weight. There are no internationally agreed standards or guidelines available for the remaining trace metals and chlorinated hydrocarbons in shellfish. Therefore, these results were compared with the strictest standard or guidance values for shellfish, which are applied by contracting countries to the OSPAR Convention, and were found to be well below the strictest values listed. This is evidence of the clean, unpolluted nature of Irish shellfish and shellfish producing waters. As in previous years, the water quality from shellfish growing areas was good and conformed to the requirements of the Directive. Petroleum hydrocarbons were not visible in any of the shellfish waters or as deposits on the shellfish. This survey confirms previous studies (Glynn et al., 2003a, 2003b; McGovern et al., 2001; Bloxham et al., 1998; Smyth et al., 1997 and Nixon et al., 1995, 1994, and 1991), which show that contamination from trace metals and chlorinated hydrocarbons is low in Irish shellfish aquaculture.

In accordance with the monitoring requirements of Council Directive 79/923/EEC, on the quality required of shellfish waters, and Council Directive 91/492/EEC, laying down the health conditions for the production and placing on the market of live bivalve molluscs, water samples from major shellfish growing areas were tested for physicochemical parameters and shellfish were tested for trace metal levels. In 2003, a total of 30 samples were analysed for trace metals. All mercury concentrations measured were below or close to the limit of quantification, 0.03 mg/kg wet weight, which is well within the European maximum level of 0.50 mg/kg wet weight for mercury in bivalve molluscs. Levels of lead were typically low, with a mean of 0.26 mg/kg wet weight and maxima of 1.04 mg/kg wet weight, also below the respective European maximum level of 1.50 mg/kg wet weight. In addition, levels of cadmium were all below the European maximum level of 1 mg/kg wet weight, though the level of cadmium determined at Castlegregory in Tralee Bay was 0.97 mg/kg, close to the European limit. Castlegregory has not been included in the sampling programme since 1994, but will be included in future monitoring. There are no internationally agreed standards or guidelines available for the remaining trace metals in shellfish. A compilation by the OSPAR Commission of standard and guidance values applied by member states of OSPAR indicated the Spanish standard for copper in shellfish of 20 mg/kg wet weight to be the strictest available. This excludes oysters for which a higher standard of 60 mg/kg wet weight has been set, as oysters accumulate copper to higher levels. All copper results were within these Spanish standards. The results obtained provide evidence of the clean, unpolluted nature of Irish shellfish and shellfish producing waters. As in previous years, the water quality from shellfish growing areas was good and conformed to the requirements of the Directive. Petroleum hydrocarbons were not visible in any of the shellfish waters or as deposits on the shellfish. This survey confirms previous studies (Glynn et al., 2004, 2003a, 2003b; McGovern et al., 2001; Bloxham et al., 1998; Smyth et al., 1997 and Nixon et al., 1995, 1994, and 1991), which show that contamination from trace metals is low in Irish shellfish aquaculture.

This document outlines the proceedings of the 6th Irish Shellfish Safety Scientific Workshop. This event was organised by the Marine Institute, the Food Safety Authority of Ireland and Bord Iascaigh Mhara to discuss the methods and advances of food safety with respect to shellfish health.

This report details the investigations into a major mortality of farmed salmon at Inver Bay and McSwyne’s Bay, Co. Donegal in July 2003. Previous reports were provided on 29th July 2003 and on 11th August 2003. The information is based upon analysis and research by MI scientists, a review of environmental data, survey reports by external consultants, inputs from veterinary practitioners who visited the site, reports from DCMNR staff in Killybegs, and site visits made by DCMNR / MI inspectors. Following a review meeting of the principal investigators on the 9th October, 2003, MI proceeded to carry out further scientific investigations. DCMNR also commissioned Kirk McClure Morton Consulting Engineers (KMM) to carry out a parallel investigation of the mortalities at Inver Bay and McSwynes Bay salmon farms. MI provided support as required to the KMM study, the report for which was furnished to DCMNR and MI on 11 February 2004. (KMM, 2004) MI wishes to acknowledge the high level of co-operation and assistance that it received from the owners and staff of Creevin Fish Farm Ltd, Eany Fish Products Ltd and Ocean Farms Ltd. It also wishes to acknowledge the assistance of veterinary practitioners, DCMNR staff and others in the course of this investigation.

In the early 1990’s pancreas disease (PD) was shown to be the most significant cause of mortality in Irish farmed salmon (Wheatley et al., 1995, Menzies et al., 1996, Crockford et al., 1999). At that time the aetiology of PD was uncertain but in 1995 it was conclusively shown that PD was caused by a virus subsequently named salmon pancreas disease virus (SPDV), (Nelson et al., 1995, McLoughlin et al., 1996). It has since been further classified and named salmonid alphavirus (Weston et al., 1999, Weston et al., 2002). The clinical and histopathological features of naturally occurring pancreas disease in farmed Atlantic salmon in Ireland were described by Murphy et al., 1992 and McLoughlin et al., 2002. The original epidemiological studies of PD in Ireland indicated that mortality rates up to 48% have occurred in farmed Atlantic salmon in their first year in the sea on some individual fish farms (Menzies et al., 1996). PD was recorded in over 70% of marine sites monitored and the majority of PD outbreaks occurred during August to October (Crockford et al., 1999). A serological survey for the presence of SPDV antibody in 1996 revealed 53% of the sites (9/17) were positive and that not all positive sites had recognised clinical signs of PD. This indicated a relatively low incidence and severity of PD at that time (McLoughlin et al., 1998). This pattern persisted until 2002 when there was a serious increase in both the incidence and severity of PD reported on farmed Atlantic salmon marine sites in Ireland. In order to identify factors associated with this re-emergence of PD in Irish farmed salmon, an in-depth epidemiological investigation was carried out on all marine sites. In trying to identify the cause of a disease from epidemiological studies the concept of time, place and individual is paramount, i.e. why did a particular disease occur in a particular animal or group of animals at a particular time in a particular place? Epidemiological study designs are chosen so that predictor variables are measured in affected and non-affected “units”. These “units” may be cells, animals, pens, farms or countries. The association between these predictor variables and disease is then examined. Where associations are demonstrated then risk factors for disease can be identified. A risk factor is a predictor variable associated with the disease. However the identification of a risk factor does not imply causation. The strength, consistency, temporality and dose response effect of the risk factor add weight to it being causal but only an intervention study where the risk factor is added or omitted can confirm this. Individual or univariate analysis of the relationship between a predictor variable and disease may result in an association being demonstrated. However it is dangerous to read too much into univariate analyses as factors which have been ignored, not measured or not seen as important may have a confounding effect. Multivariate analysis is used to try to provide estimates of association adjusted for the effect of confounding factors is a much more accurate and powerful epidemiological tool, but was of limited application in this snapshot survey of a single production cycle. This report aims to describe the occurrence and severity of PD in Irish farmed salmon in 2002-2003 and to identify risk factors associated with the re-emergence of severe PD. Finally, recommendations are made on how PD can be managed to reduce its serious impact on the health, welfare and productivity of Irish farmed salmon.

The European Union project “Investigation into the monitoring, analysis and toxicity of toxaphene” (MATT), involving participants from The Netherlands, Ireland, Norway and Germany, began in 1997. Analytical methodology, concentration information and statistical interpretation of results for three indicator congeners, CHB’s 26, 50 and 62, are presented. Data from 55 samples, covering 18 different fish species, from Irish waters are documented. Concentrations were lowest in shellfish and in fish species having low lipid content and were highest in medium/high lipid species. Males from a number of fish species were shown to contain significantly higher concentrations than observed in female fish. Overall no samples were shown to exceed existing German MRL or Canadian TDI recommendations.

Major shellfish growing areas were sampled in accordance with the monitoring requirements of Council Directive 79/923/EEC, on the quality required of shellfish waters, and Council Directive 91/492/EEC, laying down the health conditions for the production and placing on the market of live bivalve molluscs. Data for physicochemical parameters in water, trace metal levels and chlorinated hydrocarbon concentrations in shellfish are presented. In 2001, a total of 23 samples from 20 different shellfish sites were analysed for trace metals and chlorinated hydrocarbons. The median concentration of mercury in shellfish sampled in 2001 was <0.03 mg/kg wet weight, with a maximum of 0.04 mg/kg wet weight which is well within the maximum limit of 0.50 mg/kg wet weight for mercury in bivalve molluscs set by the EU. The levels of lead and cadmium detected were low, with means of 0.20 and 0.24 mg/kg wet weight and maxima of 0.37 and 0.74 mg/kg wet weight respectively, also within the respective maximum levels of 1.50 and 1 mg/kg wet weight set by the EU. There are no internationally agreed standards or guidelines available for the remaining trace metals and chlorinated hydrocarbons in shellfish. However these results were compared with the strictest standard or guidance values for shellfish, which are applied by contracting countries to OSPAR, and were found to be well below the strictest values listed. This is evidence of the clean, unpolluted nature of Irish shellfish and shellfish producing waters. As in previous years, the water quality from shellfish growing areas was good and conformed to the requirements of the Directive. Petroleum hydrocarbons were not visible in any of the shellfish waters or as deposits on the shellfish. This survey confirms previous studies (Glynn et al., 2003; McGovern et al., 2001; Bloxham et al., 1998; Smyth et al., 1997 and Nixon et al., 1995, 1994, and 1991), which show that contamination from trace metals and chlorinated hydrocarbons is low in Irish shellfish aquaculture.

Concerns over recent expansion of the aquaculture sectors in Mulroy Bay have lead to several investigations on environmental quality within the area, including a recent report (in 2000) for the Irish Marine Institute by the Centre for Marine Resources and Mariculture (C-Mar, 2000). This study reported on changes in the physical and chemical environment within Muloy Bay over a two year data collection period, and from data collected by Marine Harvest Ireland, and related observed changes to aquaculture (notably salmon farming) outputs. The study also involved sediment bioassays using sediment collected in Mulroy Bay and a variety of test organisms to investigate whether any toxicants were present that may affect the benthic community. The current study was commissioned by the Marine Institute to draw together the results of long term monitoring of water and sediment quality, and hydrography, within Mulroy Bay collected by the Institute of Aquaculture (IoA), Stirling, on behalf of Marine Harvest Ireland since 1986. The study examines trends in the physical and chemical environment within Mulroy Bay (predominantly using IoA data) since recording began, and relates results to the present activities within the bay. The aims of the study are: • to produce a carrying capacity model for Mulroy Bay as a whole • to produce maps of waste dispersion from fish cage sites • to assess the environmental sustainability of current aquaculture activities in Mulroy Bay

Major shellfish growing areas were sampled in accordance with the monitoring requirements of Council Directive 79/923/EEC, on the quality required of shellfish waters, and Council Directive 91/492/EEC, laying down the health conditions for the production and placing on the market of live bivalve molluscs. Data for physicochemical parameters in water, trace metal levels and chlorinated hydrocarbon concentrations in shellfish are presented. EU Commission Regulation 466/2001/EC (as amended by Regulation 221/2002/EC) came into effect on 5th April 2002. This set maximum levels for mercury, cadmium and lead in bivalve molluscs of 0.5mg/kg, 1mg/kg, and 1.5mg/kg wet weight respectively. In the absence of EU standards for other contaminants in shellfish, monitoring results have been compared to strictest guidance or standard values available in other OSPAR Convention contracting countries. As in previous years, the water quality from shellfish growing areas was good and conformed to the requirements of the Directive. Petroleum hydrocarbons were not visible in any of the shellfish waters or as deposits on the shellfish. Levels of chlorinated hydrocarbons and trace metals in shellfish tissue were very low in all areas, which is evidence of the clean, unpolluted nature of Irish shellfish and shellfish producing waters. This survey confirms previous studies (McGovern et al., 2001; Bloxham et al., 1998; Smyth et al., 1997 and Nixon et al., 1995, 1994, and 1991), which show that contamination from trace metals and chlorinated hydrocarbons is low in Irish shellfish products.