Browsing Marine Environment & Food Safety Services by Title
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Use of LC-MS testing to identify lipophilic toxins, to establish local trends and interspecies differences and to test the comparability of LC-MS testing with the mouse bioassay: an example from the Irish biotoxin monitoring programme 2001During 2001, the Marine Institute has extended its range of chemical tests to include the analysis of DSP toxins by Liquid Chromatography coupled to Mass Spectrometry (LC-MS). Thus the range of compounds determined extends from domoic acid over DSP compounds (okadaic acid and DTXs) to azaspiracids (AZAs). These tests complement the mouse bioassay, which is the current reference method for lipophilic toxins within the European Community. The development and performance characteristics of the LC-MS method are discussed. Isomer patterns and interspecies differences are discussed as well as local trends in time and variability at one production site at a given time. Comparison of the LC-MS results with the results from the mouse bioassay showed good agreement (93%), and a small but significant number of discrepancies (7%). Overall, the chemical testing has proven to be an invaluable tool in the assessment of shellfish toxicity in Ireland. Lacks of standards and reference materials are discussed as well as the need for further research into the equivalence of methods.
Utilising caging techniques to investigate metal assimilation in Nucella lapillus, Mytilus edulis and Crassostrea gigas at three Irish coastal locationsPollution by metals has been of increasing concern for a number of decades but at present, the mechanism of metal accumulation in sentinel species is not fully understood and further studies are required for environmental risk assessment of metals in aquatic environments. The use of caging techniques has proven to be useful for assessment of water quality in coastal and estuarine environments. This study investigates the application of caging techniques for monitoring uptake of 20 elements [Li, Na, Mg, Al, P, K, Ca, V, Cr, Mn, Fe, Ni, Co, Cu, As, Sb, Pb, Hg, Cd and Zn] in three marine species namely Nucella lapillus, Mytilus edulis and Crassostrea gigas. Stable isotopes were used to determine predatory effects and also used for modelling metal uptake in test species and to track nutrient assimilation. Metal levels were monitored at three different coastal locations, namely Dublin Bay, Dunmore East and Omey Island over 18 weeks. Significant differences in concentrations of Mn, Co and Zn between mussels and oysters were found. Correlations between cadmium levels in N. lapillus and δ13C and δ15N suggest dietary influences in Cd uptake. Levels of Zn were highest in C. gigas compared to the other two species and levels of Zn were most elevated at the Dunmore East site. Copper levels were more elevated in all test species at both Dublin Bay and Dunmore East. Mercury was raised in all species at Dunmore East compared to the other two sites. Biotic accumulation of metals in the test species demonstrates that caging techniques can provide a valid tool for biomonitoring in metal impacted areas.
Viral gametocytic hypertrophy of the Pacific oyster Crassostrea gigas in IrelandViral gametocytic hypertrophy (VGH) was detected during an investigation of mortalities in Pacific oysters Crassostrea gigas from 2 separate Irish production sites. The basophilic inclusions were observed in the gonad tissue of oysters sampled in August and October 2007. The oysters involved did not show any macroscopic disease signs. Transmission electron microscopy demonstrated the presence of viral particles in these intranuclear inclusions. The particles were small, non-enveloped, icosahedral and approximately 50 nm in diameter and thus had characteristics similar to the Papillomaviridae and Polyomaviridae families. No host defence reaction was observed. The viral particles described here appear to be similar to those described in C. virginica from the USA and Canada and to those described in C. gigas from Korea and France.
Water Framework Directive: marine ecological tools for reference, intercalibration and classification (METRIC): final report for the ERTDI-funded project: 2005-W-MS-36Water quality monitoring programmes exist in many of the Member States throughout the European Union (EU). With the implementation of the Water Framework Directive (WFD, Council Directive 2000/60/EC) all Member States must harmonise their national monitoring methods for each common metric (parameter indicative of a biological water quality element) used to determine the state of the aquatic environment to ensure consistent and comparable classification results for all biological community quality elements used (WFD Annex V, 1.4.1). The Marine Ecological Tools for Reference, Intercalibrationand Classification (METRIC) project, therefore, was designed specifically to support the Irish role in the EU Intercalibration Exercise of biological quality elements (BQEs) in order to set harmonised ecological quality criteria for the assessment of water quality in the transitional and coastal (TraC) waters of Europe. The BQEs investigated by METRIC included: Plants (phytoplankton, macroalgae andangiosperms), Benthic macroinvertebrates (soft-bottom habitat), Fish (estuarine).