• Karenia mikimotoi: An Exceptional Dinoflagellate Bloom in Western Irish Waters, Summer 2005

      Silke, J.; O'Beirn, F.X.; Cronin, M. (Marine Institute, 2005)
      A protracted bloom of Karenia mikimotoi was present in summer 2005 along the northern half of the western Irish coastline. The onset of this bloom was identified in late May / early June. This event subsequently dissipated over the month of July and was succeeded by a bloom of the same species in the southwest in late July. The bloom was very intense and resulted in discolouration of seawater and foaming in coastal embayments. Major mortalities of benthic and pelagic marine organisms were observed and a complete decimation of marine faunal communities was reported and observed in several locations. Deaths of echinoderms, polychaetes and bivalve molluscs were observed in County Donegal and Mayo, while farmed shellfish and hatchery raised juvenile bivalve spat suffered significant mortalities along the Galway and Mayo coasts. Reports of dead fish and crustacea were received from Donegal, Galway, West Cork and Kerry. Karenia mikimotoi is one of the most common red tide causative dinoflagellates known in the Northeast Atlantic region, and is also common in the waters around Japan. Blooms of this species often reach concentrations of over several million cells per litre and these densities are often associated with marine fauna mortalities. Although cytotoxic polyethers have been extracted from cultures of the species, the exact mechanism of the toxic effect and resultant devastating damages yet remains unclear. It is known in the literature under several different names as the taxonomy and genetics have been studied. It is now known that previously reported names including Gyrodinium aureolum, G. cf. aureolum, G. nagasakiense and G. mikimotoi are synonymous with the current name given to the organism. The visible effects following the mortalities included noticeable quantities of dead heart urchins (Echinocardium cordata L.) and lugworms (Arenicola marina L.) deposited on beaches. Several species of wild fish were also found dead. The bloom coincided with a period of fine weather and tourists visiting the seaside were concerned about the safety of swimming in waters that were obviously harmful to marine organisms on this scale. A public awareness programme was mounted by the Marine Institute with several radio broadcasts, press releases and a website provided to give up to date pronouncements on the event. While there have been several instances of Karenia mikimotoi blooms reported in Ireland over the past 30 years, this scale of mortalities associated with the 2005 bloom were not previously observed. Recording the scale of this event was facilitated by satellite imagery while direct counts of the cells in seawater by the Marine Institute monitoring programme gave very useful information regarding the size and intensity of this event. The mortalities of marine organisms were documented from reports made by various observers and by Marine Institute field surveys.
    • Management recommendations for the sustainable exploitation of mussel seed in the Irish Sea

      Maguire, J A; Knights, T; Burnell, G; Crowe, T; O'Beirn, F.X.; McGrath, D; Ferns, M; McDonough, N; McQuaid, N; O'Connor, B; et al. (Marine Institute, 2007)
      As it currently stands, the management of the bottom mussel aquaculture in Ireland is a complex process that is governed by three overriding factors; these are; 1) Government policy and regulation, 2) industry and economics and 3) Science and biology. These three factors are influenced by a range of different issues that influence the implementation of resource management either individually or in combination and include, inter alia, aquaculture licensing, carrying capacity, company structure and operating practices, animal health legislation, vessel registration and licensing and North/South agreements, prevailing weather conditions and uncertainty of seed supply. The mussel seed fishery in the Irish Sea, as the primary source of seed, is integral to the continued viability of the bottom mussel sector in Ireland. This report is the outcome of a project initiated over concerns raised regarding the sustainability of the fishery. A goal of this project is to develop and implement a science based management system for the sustainable exploitation of seed mussels in the Irish Sea. A specific goal of the project was to identify environmental drivers governing the distribution and abundance of the seed mussel resources in the Irish Sea. A number of outputs were expected from this project: 1. A literature search and review of existing biological, fisheries, survey and hydrographic data. 2. Studies to estimate adult reproductive cycles and spatfall patterns. 3. Hydrographic models of targeted areas of high mussel population. These models allow for behavioural characteristics of the larval swimming phases. 4. Draft a management strategy to detail the optimum manner in which to effect the sustainable exploitation of the resource, including the hatchery option. This report addresses the final workpackage above, wherein a series of recommendations encompassing both management and research aspects, based upon the scientific outputs of the project, are presented.
    • Monitoring of Tributyl Tin Contamination in Six Marine Inlets using Biological Indicators

      Minchin, D (Marine Institute, 2003)
      Dogwhelk and periwinkle specimens were collected from six bays/estuaries in 2000, where Tributyl Tin (TBT) contamination was suspected. In four estuaries, shells of dead Pacific oysters were collected from 7 sites in the vicinity of culture installations. Observations on imposex in dogwhelks, intersex in periwinkles and shell thickness in the Pacific oysters were used to assess the degree of TBT contamination. The results showed low levels of contamination, which are unlikely to have detrimental effects to mollusc culture or fisheries in Mulroy Bay, Valentia Harbour or Tralee Bay. Thickening of oyster shells was detected in Carlingford Lough, Waterford Harbour, Cork Harbour and Fountainstown. The small degree of thickening was considered unlikely to affect marketability.
    • Monitoring of zebra mussels in the Shannon-Boyle navigation, other

      Minchin, D; Lucy, F; Sullivan, M (Marine Institute, 2002)
      The zebra mussel (Dreissena polymorpha) population has been closely monitored in Ireland following its discovery in 1997. The species has spread from lower Lough Derg, where it was first introduced, to most of the navigable areas of the Shannon and other interconnected navigable waters. This study took place in the summers of 2000 and 2001 and investigated the relative abundance and biomass of zebra mussels found in the main navigations of the Shannon and elsewhere in rivers, canals and lakes where colonisation was likely. During 2000 zebra mussels were found for the first time in Carnadoe, Kilglas and Grange Loughs on the River Shannon. In 2001, they were discovered on the Ballinasloe Navigation at Poulboy Lough and in Ballinasloe Harbour. For the first time outside of the Shannon-Boyle navigation, established populations were discovered in Garadice Lough on the Shannon-Erne Waterway and in Ringsend Basin and Tullamore Harbour on the Grand Canal. Zebra mussels continue to have their greatest densities in lakes and large reservoirs of the Shannon-Boyle navigation. A maximum biomass of 4.1kg per sq.m was recorded in Lough Key. No zebra mussel larvae or their attached stages were found in the larger lakes outside of the Shannon-Boyle and Erne Navigations. Larvae were found however, in Tullamore Harbour for the first time. In separate studies approximately two hundred adults were found in Lough Bo, Co. Sligo and less than ten specimens were found in Lough Gill, Co. Sligo. The only living population of native freshwater mussels (Anodonta spp.) presently known in the lake regions of the Shannon is in the Carnadoe Cut, between Carnadoe Lough and Kilglas Lough. This population of Anodonta spp. is fouled with zebra mussels. Freshwater mussels were also found in Garadice Lough and Assaroe Reservoir. These were also fouled with zebra mussels.
    • The Occurrence and Risk Assessment of the Pesticide Toxaphene in Fish from Irish Waters

      McHugh, B; Glynn, D; Nixon, E; McGovern, E (Marine Institute, 2003)
      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.
    • Pancreas Disease in Farmed Salmon - Health Management and Investigations at Irish Farm Sites 2005-2008

      Graham, D; Rodger, H; Ruane, N. M. (Marine Institute, 2008)
      This publication constitutes the final report for the research project ST/05/01 “Site investigations and disease management of the pancreas disease virus in Irish farmed salmon”, funded under the NDP Marine RTDI Programme. Work undertaken within the project included longitudinal studies of rainbow trout and Atlantic salmon at sea following the course of infection, testing for vectors and reservoirs of the virus, molecular studies of the virus and an epidemiological investigation of pancreas disease in Ireland. Results have shown that although pancreas disease is endemic in marine farmed Atlantic salmon, no evidence of infection in rainbow trout farmed at sea was found. Serological and molecular based diagnostic methods were shown to be suitable for the screening of fish stocks for the presence of the virus. For the confirmation of clinical outbreaks, farm data and histopathological results should be included. The results also suggest that horizontal transmission of the virus may be the main route of infection between sites. The project also involved the technology transfer of molecular and serological diagnostic methods for pancreas disease between partners and the final chapter includes practical information on management of, and mitigation against, pancreas disease. Pathologies such as pancreas disease, heart and skeletal muscle inflammation and cardiomyopathy syndrome, pose a serious threat to salmonid farming in Ireland, Scotland and Norway. Most significant among this group of diseases is pancreas disease, a viral disease affecting Atlantic salmon during the marine stage of the production cycle. From the first description of pancreas disease in farmed Atlantic salmon from Scotland in 1976 the disease has now become endemic in Ireland and parts of Norway and continues to be significant in Scotland. The causal agent of pancreas disease, a salmonid alphavirus, has now been characterised and a closely related subtype of the virus is known to cause sleeping disease in farmed rainbow trout on continental Europe and in the United Kingdom. The Irish salmon farming industry has estimated that pancreas disease has resulted in a total loss of turnover of €35 million with €12 million loss of profit in the years 2003-2004. The economic impacts are estimated to be in the range of €100 million per year in Norway. In Scotland, pancreas disease and related pathologies are increasingly responsible for significant losses in marine salmon farms but these have yet to be quantified.
    • Pilot Water Quality Monitoring Station in Dublin Bay North Bank Monitoring Station (NBMS): MATSIS Project Part I

      O'Donnell, G; Joyce, E; O'Boyle, S; McGovern, E (Marine Institute, 2008)
      The lack of short-term temporal resolution associated with traditional spot sampling for monitoring water quality of dynamic coastal and estuarine waters has meant that many organisations are interesting in autonomous monitoring technologies to provide near real-time semi-continuous data. Such approaches enable capturing short term episodic events (which may be missed or alternatively skew datasets when using spot samples) and provide early warning of water quality problems. New policy drivers such as the Water Framework Directive (WFD) provide added impetus to develop this field. Therefore, as part of the interreg IIIa funded MATSIS project the Marine Institute undertook to develop and pilot an autonomous monitoring station in Dublin Bay (North Bank Monitoring Station NBMS). This report presents the outcome for this pilot study.
    • Proceedings of the 5th Irish Shellfish Safety Workshop, Rosscarbery, October 28th 2004

      Marine Institute (Marine Institute, 2005)
      This document outlines the proceedings of the 5th 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.
    • Proceedings of the 6th Irish Shellfish Safety Scientific Workshop

      Marine Institute (Marine Institute, 2006)
      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.
    • Proceedings of the 7th Irish Shellfish Safety Workshop

      Marine Institute (Marine Institute, 2007)
      This document outlines the proceedings of the 7th 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.
    • Proceedings of the 8th Irish Shellfish Safety Workshop

      McMahon, T.; Deegan, B.; Silke, J.; Ó Cinneide, M. (Marine Institute, 2008)
      This document outlines the proceedings of the 8th 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.
    • Proceedings of the 9th Irish Shellfish Safety Scientific Workshop

      Gilmartin, M.; Silke, J. (Marine Institute, 2009)
      The 9th Irish Shellfish Safety Workshop was held on the 20th March, 2009, in Kenmare, County Kerry. The Workshop was co-sponsored by the Marine Institute, Bord Iascaigh Mhara, the Food Safety Authority of Ireland, and the Sea Fisheries Protection Authority, with support from IFA Aquaculture. The topics addressed at the workshop included an update on the National Biotoxin monitoring programme, and a number of research projects with Irish participation and international perspectives on toxin detection. Finding mechanisms to improve our product was a common theme with presentations on improving food safety, increasing productivity, providing easily applied test methods, and research in support of the shellfish industry. The focus of the three Workshop sessions was on a review of the year, research and legislation.
    • Research on Pancreas Disease in Irish Farmed Salmon 2004/2005 – Current and Future Initiatives

      Rodger, H; Graham, D; Foyle, L; Norris, A; Ratcliff, J; Murphy, K; Mitchell, S; Staples, C; Jewhurst, H; Todd, D; et al. (Marine Institute, 2005)
      Pancreas Disease is the most significant single infectious disease affecting marine salmon farms in Ireland. The first epidemiological studies of Pancreas Disease (PD) in Ireland in the early 1990’s indicated that significant losses occurred in farmed Atlantic salmon in their first year at sea on some individual farms (Menzies et al., 1996). A serological survey for the presence of Salmon Pancreas Disease Virus (SPDV) antibody in 1996 revealed that 53% of Irish sites were positive, but 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) and this pattern persisted throughout the remainder of the 1990’s. In 2002, a serious increase in both the incidence and severity of PD was reported on farmed Atlantic salmon marine sites in Ireland. An epidemiological survey of Irish sites for 2002 revealed that 59% of sites reported an outbreak of PD, with mortalities averaging 12% (range 1 – 42%; McLoughlin et al., 2003). A recent study using data collected for 2003 and 2004 indicated that PD occurred in 62% and 86% of sites respectively. The average mortality due to PD on affected farms was 18.8% in 2003 and 14.8% in 2004. In response to these significant losses due to PD a range of research initiatives was launched in Ireland and was supported by the Marine Institute. This document gives an overview of the most recent findings from the current projects, carried out in 2004/2005 and also provides an overview of the various actions in Scotland and Norway, where PD has also become a disease of economic significance in salmon aquaculture.
    • Review of the Potential Mechanisation of Kelp Harvesting in Ireland

      Werner, A; Kraan, S (Marine Institute, 2004)
      A diverse seaweed industry has developed in Ireland over the past few decades. The seaweed industry today comprises several sectors, such as biopolymers, agriculture/horticulture, cosmetics, thalassotherapy and human consumption, with the former two sectors being of most economic importance. Approximately sixteen seaweed species are commercially utilised, three of which are of particular commercial importance. These are the calcified red algae, referred to as maërl, which mainly comprises of two species (Phymatolithon calcareum and Lithothamnion corallioides) and are exploited by a single company for agricultural, horticultural, food and cosmetic applications. The other bulk species is the brown alga Ascophyllum nodosum, which is used for alginate extraction and agriculture/horticulture applications. The latter species sustains an industry, which is an important factor in contributing to the maintenance of coastal communities especially in rural areas of the west coast, particularly in the Gaeltacht of Connemara (Guiry 1997, National Seaweed Forum, 2000). Mechanical harvesting of seaweeds in Ireland is limited to the exploitation of maërl. At present, one company has a licence to harvest calcified algae in the south-west of Ireland (Bantry Bay) with 8,000 - 10,000 wet tonnes of maërl being extracted from the seabed annually in recent years. The supply of raw material for the Ascophyllum-processing industry as well as for the other industrial sectors relies on harvesters who harvest the seaweed by hand. Although hand-harvesting provides a source of employment in rural areas along the west coast, the age profile is increasing and the numbers of harvesters are declining due to insufficient recruitment of younger harvesters (National Seaweed Forum 2000; Kelly et al. 2001). With growing demands for seaweeds, it is uncertain whether hand-harvesting will provide sufficient raw material in the long-term. The National Seaweed Forum has evaluated the current state of the Irish Seaweed Industry. The forum was launched by the Minister for Marine and Natural Resources in 1999 and consists of 19 members from state agencies, third-level institutions and industry. In the final report (National Seaweed Forum, 2000) it was stated that the natural sustainable seaweed resources in Ireland are under-utilised and the industrial potential, including high-value applications, has not been fully realised. The National Seaweed Forum identified two key areas as being crucial to the development of the Irish seaweed industry: 1) Seaweed aquaculture was assumed to provide the most cost-effective method to meet growing market demand with high-quality seaweed for specific sectors such as human consumption, cosmetics and biotechnology. Additionally, a seaweed aquaculture industry is expected to create attractive and high-skilled jobs, especially in peripheral communities in coastal areas. This is based on the fact that seaweeds of interest to high quality applications are often not bulk species, which are easy to harvest in large amounts. Therefore, with cultivation you strongly increase volume/area, which facilitates harvesting and also standardises quality. Cultivation of a bulk species such as kelp is economically not feasible in Europe. 2) The development and introduction of harvesting machinery suitable for Irish conditions was thought to have a significant impact on the expansion of a viable Irish seaweed industry. As a measure to ensure long-term continuity of raw-material supply of bulk species (e.g. A. nodosum, Laminaria species) the investigation of mechanical harvesting techniques with emphasis on sustainability and environmental impact were prioritised as an R&D area (National Seaweed Forum, 2000). An initial comprehensive study of hand and mechanical harvesting of Ascophyllum nodosum, including an environmental impact assessment, was conducted in the late 1990s (Kelly et al., 2001). In this study, a device similar to the Norwegian Ascophyllum cutter (a flat-bottomed boat fitted with a Vaughan vertical wet-well chopper pump) was used. When hand and mechanical harvesting were compared, there was no significant difference in environmental impact caused by the two methods, but mechanical harvesting was found to be less effective and more expensive than hand harvesting. At present, kelp species in Ireland such as L. digitata, L. saccharina and Alaria esculenta, are harvested by hand but only in small amounts. This means that the natural sustainable resources of kelps of Irish shores are under-utilised. Due to the economic importance of L. digitata and L. hyperborea for alginate extraction and the growing demand for kelp by the phycocolloid and other industries, the introduction of mechanical harvesting is currently being considered for Ireland. Mechanised harvesting enables the harvester to remove large amounts of biomass from an area in a relatively short time. It is therefore essential to develop a suitable management scheme to ensure sustainable exploitation of natural resources and continuous integrity of marine habitats. The objective of the present study is to provide an extensive literature review on kelp research, harvesting and resource management as essential background knowledge for the development of an appropriate management strategy for Ireland. The report addresses the following topics: • Biology of kelps • Biodiversity of kelp forests and ecological significance of kelps • Commercial kelp harvesting in France and Norway (methods, management and environmental impact) • Investigations of kelp in Ireland (Growth rates, biomass, biodiversity of kelp beds, regeneration potential, kelp resources) • Legal framework for seaweed harvesting in Ireland • Conclusions and recommendations
    • Salmon Mortalities at Inver Bay and McSwyne’s Bay Finfish farms, County Donegal, Ireland, during 2003

      Cronin, M.; Cusack, C.; Geoghegan, F.; Jackson, D.; McGovern, E.; McMahon, T.; O'Beirn, F.X.; Ó Cinneide, M.; Silke, J. (Marine Institute, 2004)
      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.
    • Trace Metal and Chlorinated Hydrocarbon Concentrations in Shellfish from Irish Waters 2001

      Glynn, D; Tyrrell, L; McHugh, B; Rowe, A; Monaghan, E; Costello, J; McGovern, E (Marine Institute, 2003)
      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.
    • Trace Metal and Chlorinated Hydrocarbon Concentrations in Shellfish from Irish Waters 2002

      Glynn, D; Tyrrell, L; McHugh, B; Monaghan, E; Costello, J; McGovern, E (Marine Institute, 2004)
      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.
    • Trace Metal and Chlorinated Hydrocarbon Concentrations in Shellfish from Irish Waters, 1997-1999

      McGovern, E; Rowe, A; McHugh, B; Costello, J; Bloxham, M; Duffy, C; Nixon, E (Marine Institute, 2001)
      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, the Marine Institute collected water and shellfish samples from major shellfish growing areas and analysed for physicochemical parameters, trace metal levels and chlorinated hydrocarbon concentrations. Since, with the exception of mercury, there are no currently applicable European standards for the concentration of these contaminants in shellfish, the levels were compared with the available standards and guidance values for human consumption, as compiled by the Oslo and Paris Commission (OSPAR) countries. As in previous years, the water quality from shellfish growing areas was good and conformed to the guidelines and requirements of the Directive. Petroleum hydrocarbons were not observed in any of the shellfish waters or as deposits on the shellfish. Chlorinated hydrocarbon levels were very low, evidence of the clean, unpolluted nature of Irish shellfish and shellfish producing waters. Trace metal levels were consistently low with the exception of cadmium in oyster tissue, which was slightly elevated in the 1999 samples from Clew Bay, Inner Tralee Bay, Aughinish Limerick and Kilkieran. However these levels did not exceed the Dutch human consumption standard value or the EU maximum limit of 1.0 mg/kg wet weight due to apply from 2002. This survey confirms previous studies which show Irish shellfish products are effectively free from trace metal and chlorinated hydrocarbon contamination.
    • Trace Metal and Chlorinated Hydrocarbon Concentrations in Shellfish from Irish Waters, 2000

      Glynn, D; Tyrrell, L; McHugh, B; Rowe, A; Costello, J; McGovern, E (Marine Institute, 2003)
      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.
    • Trace Metal and Chlorinated Hydrocarbon Concentrations in Various Fish Species Landed at Selected Irish Ports, 1997-2000

      Tyrrell, L; Glynn, D; Rowe, A; McHugh, B; Costello, J; Duffy, C; Quinn, A; Naughton, M; Bloxham, M; Nixon, E; et al. (Marine Institute, 2003)
      The Marine Institute samples a range of finfish species landed at five major Irish ports on an annual basis, in accordance with the monitoring requirements of various European legislation designed to ensure food safety. During 1997 – 2000, a total of 112 samples from 23 different species of finfish were collected from five major Irish fishing ports and analysed for total mercury concentration in the edible. The concentration of mercury ranged from 0.03 to 0.18 mg/kg wet weight in 1997, <0.03 to 0.19 mg/kg wet weight in 1998, <0.03 to 0.29 mg/kg wet weight in 1999 and 0.03 to 0.33 mg/kg wet weight in 2000. These levels are well within the maximum limit of 0.50 mg/kg wet weight for mercury in fishery products set by the EC. This survey confirms previous studies, which show that Irish seafoods are 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 standard or guidance value for fish tissue, which are applied by contracting parties to OSPAR. The levels of these additional contaminants are well below the strictest values listed.