Shephard S.,Mayo Institute of Technology, Galway |
Reid D.G.,Marine Institute of Ireland |
Greenstreet S.P.R.,Marine Scotland - Marine Laboratory
ICES Journal of Marine Science | Year: 2011
The large fish indicator (LFI) was developed in the North Sea as a size-based indicator of fish community state. It is now established as OSPAR's fish community Ecological Quality Objective (EcoQO) metric and will be applied across all OSPAR regions. To produce a protocol for use when developing regional LFIs, the North Sea experience is interpreted using data from the Celtic Sea. Differences in fish community species composition and size distribution were reflected in a different species complex and large fish threshold (50 cm) for the Celtic Sea LFI. However, a lag of 12-14 years in the relationship between assemblage-averaged fishing mortality F com,y and the LFI suggested similar underlying ecological mechanisms to the North Sea. The indicator responded to changes in small fish biomass that follow fishing-induced changes in the level of predation by large demersal piscivores. The Celtic Sea LFI showed maximum observed values >0.40 before 1990, and 0.40 is here proposed as an EcoQO. Development of regional LFIs demands a flexible process rather than a strictly prescriptive protocol. © 2011 International Council for the Exploration of the Sea.
Kraak S.B.M.,University College Cork |
Kraak S.B.M.,Marine Institute of Ireland
Fish and Fisheries | Year: 2011
In situations of declining or depleted fish stocks, exploiters seem to have fallen prey to the Tragedy of the Commons, which occurs when the maximisation of short-term self-interest produces outcomes leaving all participants worse off than feasible alternatives would. Standard economic theory predicts that in social dilemmas, such as fishing from a common resource, individuals are not willing to cooperate and sacrifice catches in the short term, and that, consequently, the resource is overharvested. However, over the last decades, a multitude of research has shown that humans often achieve outcomes that are 'better than rational' by building conditions where reciprocity, reputation, and trust help to overcome the temptations of short-term self-interest. The evolution of the natural human tendency to cooperate under certain conditions can be explained, and its neuro-physiological and genetic bases are being unravelled. Nevertheless, fisheries management still often deploys top-down regulation and economic incentives in its aim to regulate fisher behaviour, and under-utilizes the potential for spontaneous responsible fisher behaviour through setting conditions that enhance natural cooperative tendencies. Here I introduce this body of knowledge on how to overcome the Tragedy of the Commons to the audience of fisheries scientists, hoping to open up novel ways of thinking in this field. I do this through a series of thought experiments, based on actual published experiments, exploring under what conditions responsible and cooperative fisher behaviour can be expected. Keys include reputation-building and indirect reciprocity, face-to-face communication, knowledge on the state of the resource, and self-decision on rules and sanctions. © 2010 Blackwell Publishing Ltd.
Kilcoyne J.,Marine Institute of Ireland |
Fux E.,U.S. Food and Drug Administration
Journal of Chromatography A | Year: 2010
Considerable efforts are being made worldwide to replace in vivo assays with instrumental methods of analysis for the monitoring of marine biotoxins in shellfish. Analysis of these compounds by the preferred technique of liquid chromatography tandem mass spectrometry (LC-MS/MS) is challenged by matrix effects associated with the shellfish tissues. In methods validation, assessment of matrix interferences is imperative to ensure the validity and accuracy of results being produced. Matrix interferences for the analysis of okadaic acid (OA) and azaspiracid 1 (AZA1) were assessed using acidic methods on electrospray triple stage quadrupole (TSQ) and hybrid quadrupole time of flight (QToF) instruments by the use of matrix matched standards for different tissue types. Using an acidic method no matrix interference and suppression was observed on the TSQ for OA and AZA1 respectively, whilst the opposite was observed on the QToF; matrix enhancement for OA and no matrix interference for AZA1. The suppression of AZAs on the TSQ was found to be due to interfering compounds being carried over from previous injections. The degree of suppression is very much dependant on the tissue type ranging from 15 to 70%. Several strategies were evaluated to eliminate these interferences, including the partitioning of the extract with hexane, optimisation of the chromatographic method and the use of on-line SPE. Hexane clean up did not have any impact on matrix effects. The use of an alkaline method and a modified acidic method eliminated matrix suppression for AZA1 on the TSQ instrument while an on-line SPE method proved to be effective for matrix enhancement of OA on the QToF. © 2010 Elsevier B.V.
Gerritsen H.D.,Marine Institute of Ireland |
Minto C.,Mayo Institute of Technology, Galway |
Lordan C.,Marine Institute of Ireland
ICES Journal of Marine Science | Year: 2013
Demersal trawling impacts extensively on the seabed, and the extent and frequency of this impact can be assessed using Vessel Monitoring System (VMS) data (positional data of fishing vessels). Existing approaches interpolate fishing tracks from consecutive VMS locations (track interpolation) and/or aggregate VMS point data in a spatial grid (point summation). Track interpolation can be quite inaccurate with the current 2-hour time interval between VMS records, leading to biased estimates. Point summation approaches currently only produce relative estimates of impact and are highly sensitive to the grid size chosen. We propose an approach that provides absolute estimates of trawling impact from point data and is not sensitive to an arbitrary choice of grid-cell size. The method involves applying a nested grid and estimating the swept area (area covered by fishing gear) for each VMS point. We show that the ratio of the swept area to the surface area of a cell can be related to the proportion of the seabed that was impacted by the gear a given number of times. We validate the accuracy of this swept-area ratio approach using known vessel tracks and apply the method to international VMS data in the Celtic Sea. © 2013 © 2013 International Council for the Exploration of the Sea. Published by Oxford University Press. All rights reserved.
Grienke U.,National University of Ireland |
Silke J.,Marine Institute of Ireland |
Tasdemir D.,National University of Ireland
Food Chemistry | Year: 2014
The consumption of marine mussels as popular seafood has increased steadily over the past decades. Awareness of mussel derived molecules, that promote health, has contributed to extensive research efforts in that field. This review highlights the bioactive potential of mussel components from species of the genus Mytilus (e.g. M. edulis) and Perna (e.g. P. canaliculus). In particular, the bioactivity related to three major chemical classes of mussel primary metabolites, i.e. proteins, lipids, and carbohydrates, is evaluated. Within the group of proteins the focus is mainly on mussel peptides e.g. those obtained by bio-transformation processes, such as fermentation. In addition, mussel lipids, comprising polyunsaturated fatty acids (PUFAs), are discussed as compounds that are well known for prevention and treatment of rheumatoid arthritis (RA). Within the third group of carbohydrates, mussel polysaccharides are investigated. Furthermore, the importance of monitoring the mussel as food material in respect to contaminations with natural toxins produced by microalgae is discussed. © 2013 Elsevier Ltd. All rights reserved.
Johnson M.P.,National University of Ireland |
Lordan C.,Marine Institute of Ireland |
Power A.M.,National University of Ireland
Advances in Marine Biology | Year: 2013
This review summarizes the data on habitat, population ecology and ecosystem roles of Nephrops norvegicus. The species has a broad range in the northeast Atlantic and Mediterranean, although it is possible that small or isolated patches of suitable habitat may not be occupied due to restrictions on larval supply. Nephrops densities are related to the silt-clay content of sediments, with interactions between habitat quality and density indicating competition for resources. An analysis of density-size interactions across fishery functional management units (FUs) suggests that growth is suppressed at high densities due to competition (e.g. in the western Irish Sea), although recruitment dynamics or size-selective mortality may also shape the size structure of populations. Nephrops biomass available across FUs may be similar, reflecting a constant yield due to the inverse relationship between individual size and population density. Gaps in the understanding of Nephrops' ecology reflect uncertain ageing criteria, reliance on fisheries-dependent data and few if any undisturbed habitats in which to examine fisheries-independent interactions. © 2013 Elsevier Ltd.
Gerritsen H.,Marine Institute of Ireland |
Lordan C.,Marine Institute of Ireland
ICES Journal of Marine Science | Year: 2011
Vessel monitoring systems (VMS) automatically collect positional data from fishing vessels, and the data can be linked to catch data from logbooks to provide a census of spatially resolved catch-and-effort data. The most appropriate and practical method for integrating Irish VMS and logbook data is explored and validated. A simple speed rule is applied to identify VMS records that correspond to fishing activity. The VMS data are then integrated with the catch data from logbooks using date and vessel identifier. Several assumptions were investigated, and the resulting distribution maps of catch and effort appear to be unbiased. The method is illustrated with an example of a time-series of spatially explicit estimates of catch per unit effort. The proposed method is relatively simple and does not require specialist software or computationally intensive methods. It will be possible to generalize this approach to similar datasets that are available within the EU and many other regions. Analysis of integrated VMS and logbook data will allow fisheries data to be analysed on a considerably finer spatial scale than was possible previously, opening up a range of potential applications. © 2010 International Council for the Exploration of the Sea. Published by Oxford Journals. All rights reserved.
O'Boyle S.,U.S. Environmental Protection Agency |
Silke J.,Marine Institute of Ireland
Journal of Plankton Research | Year: 2010
A review of the distribution of phytoplankton in coastal, shelf and estuarine waters around Ireland was undertaken to consolidate our understanding of the ecology of these organisms in the region. In broad terms, the review has highlighted the relative importance of vertical water column stability and horizontal transport processes in influencing the abundance and composition of phytoplankton. In coastal waters, the seasonal stabilization and de-stabilization of the water column accounts for most of the natural variation in both phytoplankton species composition and biomass. Much of the remaining natural variability can be explained by the interaction of phytoplankton with a number of oceanographic features and processes such as the presence of tidal and thermohaline fronts, wind and topographically associated coastal upwelling, advection landward of offshore water masses and the flow of coastal and oceanic currents. In estuarine waters, the scenario is somewhat reversed, and although seasonality is important in broad terms, the structure of phytoplankton populations is determined more by local factors operating over much smaller time-scales in the order of days and weeks. The interplay of these factors, such as the periodic rise and fall of the tide and episodic changes in river flow, creates a broad range of conditions that result in greater variation in phytoplankton biomass, while at the same time selecting for a reduced number of species that are adapted to survive in this highly changeable environment.
A sensitive liquid chromatography/tandem mass spectrometry method for the determination of natural and synthetic steroid estrogens in seawater and marine biota, with a focus on proposed water framework directive environmental quality standards
Ronan J.M.,Trinity College Dublin |
McHugh B.,Marine Institute of Ireland
Rapid Communications in Mass Spectrometry | Year: 2013
Rationale: Trace levels of natural and synthetic steroid estrogens estrone (E1), 17β-estradiol (E2) and 17α-ethynyl estradiol (EE2) have been demonstrated to exert adverse effects in exposed organisms. E2 and EE2 have been proposed for inclusion in the Water Framework Directive (WFD) list of priority pollutants; however, the detection and accurate quantification of these compounds provide significant challenges, due to the low detection limits required. Methods: A sensitive method combining ultrasonication, solid-phase extraction (SPE) and liquid chromatography/tandem mass spectrometry, with electrospray ionisation in negative mode (LC/ESI-MS/MS), capable of determining E1, E2 and EE2 at concentrations between 0.07 and 60 ng/L for seawater and between 0.4 and 200 ng/g wet weight in Mytilus spp. is reported. Recoveries at the limit of quantification (LOQ) ranged from 95 to 102% and 88 to 100% for water and tissue, respectively. Salinity (12 to 35‰) and typical marine particulate matter loadings (between 10 and 100 mg/L) were not found to affect analyte recoveries. Results: The first detection of E1 by LC/MS/MS in Irish marine waters (Dublin Bay, at 0.76 ng/L) is reported. Steroids were not detected in Galway Bay, or in any mussel samples from Dublin, Galway and Clare. The level of E2 detected in the dissolved water phase was below the proposed WFD Environmental Quality Standard (EQS) in other surface waters. Conclusions: The proposed method is suitable for the detection of E1, E2 and EE2 at biologically relevant concentrations and, due to the specificity offered, is not subject to potential interferences from endogenous E1 and E2 which often complicate the interpretation of estrogenic biomarker assays. Copyright © 2013 John Wiley & Sons, Ltd.
Dore B.,Marine Institute of Ireland
Euro surveillance : bulletin européen sur les maladies transmissibles = European communicable disease bulletin | Year: 2010
Oysters from a harvesting area responsible for outbreaks of gastroenteritis were relaid at a clean seawater site and subsequently depurated in tanks of purified seawater at elevated temperatures. This combined treatment reduced norovirus levels to those detected prior to the outbreak. On the basis of norovirus monitoring the sale of treated oysters was permitted although the harvest area remained closed for direct sale of oysters. No reports of illness have been associated with the consumption of treated oysters.