• 21st century fisheries management: a spatio-temporally explicit tariff-based approach combining multiple drivers and incentivising responsible fishing

      Kraak, Sarah B. M.; Reid, David G.; Gerritsen, H.D.; Kelly, Ciarán J.; Fitzpatrick, Mike; Codling, Edward A.; Rogan, Emer (Oxford University Press, 2012)
      Traditionally fisheries management has focused on biomass and mortality, expressed annually and across large management units. However, because fish abundance varies at much smaller spatio-temporal scales, fishing mortality can potentially be controlled more effectively if managed at finer scale. The ecosystem approach requires more indicators at finer scales as well. Incorporating ecosystem targets would need additional management tools with potentially conflicting results. We present a simple, integrated, management approach that provides incentives for “good behaviour”. Fishers would be given a number of fishing-impact credits, called real-time incentives (RTIs), to spend according to spatio-temporally varying tariffs per fishing day. RTI quotas and tariffs could be based on commercial stocks and ecosystem targets. Fishers could choose how to spend their RTIs, e.g. by limited fishing in high-catch or sensitive areas or by fishing longer in lower-catch or less sensitive areas. The RTI system does not prescribe and forbid, but instead allows fishers to fish wherever and whenever they want; ecosystem costs are internalized and fishers have to take them into account in their business decisions. We envisage no need for traditional landings or catch quotas for the fleets while operating under the scheme. The approach could facilitate further devolution of responsibility to industry.
    • Advanced Spatial Modeling to Inform Management of Data-Poor Juvenile and Adult Female Rays

      Dedman, Simon; Officer, Rick; Brophy, Deirdre; Clarke, Maurice; Reid, David G. (MDPI AG, 2017)
      Chronic overfishing has depleted numerous elasmobranch stocks in the North East Atlantic, but addressing this issue has been hampered by management complications and lacking data. Spatial management approaches have thus been advocated. This work presents a novel application and further development of an advanced spatial modeling technique to identify candidate nursery grounds and spawning areas for conservation, by subsetting already limited data. Boosted Regression Tree models are used to predict abundance of juvenile and mature female cuckoo (Leucoraja naevus), thornback (Raja clavata), blonde (Raja brachyura), and spotted (Raja montagui) rays in the Irish Sea using fish survey data and data describing fishing pressure, predation and environmental variables. Model-predicted spatial abundance maps of these subsets reveal distinct nuances in species distributions with greater predictive power than maps of the whole stock. These resulting maps are then integrated into a single easily understood map using a novel approach, standardizing and facilitating the spatial management of data-limited fish stocks.
    • Age and growth estimates for the starry smoothhound (Mustelus asterias) in the Northeast Atlantic Ocean

      Farrell, E D; Mariani, S; Clarke, M W (Oxford University Press, 2010)
      This study is the first to estimate age, growth and longevity of M. asterias based on interpretation of band pairs in sectioned vertebrae. Age and growth of 106 male and 114 female starry smooth-hound sharks (Mustelus asterias) were estimated by counting band pairs on unstained sectioned vertebrae. Growth curves were fitted to the length-at-age data using the von Bertalanffy and Gompertz models. The 1-parameter von Bertalanffy-L0 provided the best fit for males (L∞ = 104 cm TL, L0 = 30 cm TL and estimated K = 16 0.224) and females (L∞ = 133 cm TL, L0 = 30 cm TL and estimated K = 0.136). Longevity was estimated to be 11.8 and 20.2 years for males and females respectively. The length weight relationship is also presented for 304 male and 424 female M. asterias. The von Bertalanffy model was fitted to weight-at-age data. These estimates can form the basis of future work on the assessment and management of this species.
    • The age Distribution of the Herring Stocks around the Irish Coast during 1993

      Barnwall, E.; Molloy, J. (1994)
      The age distribution of stocks is usually considered as an indication of how healthy a stock may be. In general stocks which are lightly exploited will contain a much larger proportion of older fish than a stock which is heavily exploited. A stock which is heavily exploited will probably be dependent on one year class which will recruit to the fishery and which will immediately be subjected to fishing effort. Obviously in such a fishery failure of recruitment or poor recruitment will have drastic effect on the catches. Herrings can be aged accurately until are about 10 years old and generally recruit to the adult stocks during their third year. During this year, the majority of fish will spawn for the first time.
    • Anthropocene environmental change in an internationally important oligotrophic catchment on the Atlantic seaboard of western Europe

      Dalton, C; O'Dwyer, B; Taylor, D; DeEyto, E; Jennings, E; Chen, G; Poole, R; Dillane, M; McGinnity, P (Elsevier, 2014)
      Oligotrophic catchments with short spatey streams, upland lakes and peaty soils characterise northwest European Atlantic coastal regions. These catchments are important biodiversity refuges, particularly for sensitive diadromous fish populations but are subject to changes in land use and land management practices associated with afforestation, agriculture and rural development. Quantification of the degree of catchment degradation resulting from such anthropogenic impacts is often limited by a lack of long-term baseline data in what are generally relatively isolated, poorly studied catchments. This research uses a combination of palaeolimnological (radiometrically-dated variations in sedimentary geochemical elements, pollen, diatoms and remains of cladocera), census, and instrumental data, along with hindcast estimates to quantify environmental changes and their aquatic impacts since the late 19th century. The most likely drivers of any change are also identified. Results confirm an aquatic biotic response (phyto- and zooplankton) to soil erosion and nutrient enrichment associated with the onset of commercial conifer afforestation, effects that were subsequently enhanced as a result of increased overgrazing in the catchment and, possibly, climate warming. The implications for the health of aquatic resources in the catchment are discussed
    • Assessing the risk of vulnerable species exposure to deepwater trawl fisheries: the case of orange roughy Hoplostethus atlanticus to the west of Ireland and Britain

      Dransfeld, L.; Gerritsen, H.D.; Hareide, N.R.; Lorance, P. (Cambridge University Press, 2013)
      With slow growth rates, late maturity and a high maximum age of 100 years or more, orange roughy can be classified as a vulnerable deepwater fish species that can only sustain low rates of exploitation. Historical patterns of exploitation associated with this species suggest that it is currently not possible to manage its fisheries in the Northeast Atlantic sustainably, and the total allowable catch for orange roughy has been gradually reduced to zero for European fisheries since 2010. Orange roughy to the west of Ireland and Britain occurs on distinct bathymetric features (seamounts, hills and canyons) as well as on flat ground along the continental slope. Productivity-susceptibility analysis (PSA) was performed to evaluate the biological vulnerability of orange roughy in relation to other deepwater species and the risk that recent and current fisheries pose to its populations in the study area. Time-dependant PSA, based on the spatial overlap between orange roughy distribution and recent and current deepwater fisheries demonstrated a strong reduction in risk over time when fisheries stopped directed targeting practices and continued with mixed deepwater trawl fisheries. Some spatial overlap between the species and current fisheries remains, and while the method can show relative risk reduction, it cannot provide information on whether the risk is low enough to allow the recovery of depleted populations.
    • Assessing the status of shallow lakes using an additive model of biomass size spectra

      deEyto, E; Irvine, K (Wiley-Blackwell, 2007)
      1. Planktonic biomass size spectra were used to summarise the ecological quality of six shallow lakes sampled in spring, early summer and late summer. 2. A simple additive model fitted to the data was used to assess the applicability of the size spectrum theory to shallow lake ecosystems. 3. The additive model replicated the hierarchical pattern of biomass predicted by the predator-prey theory of aquatic production, and was a more appropriate model for predicting biomass size spectra than the frequently used linear regression. 4. Lakes with varying ecological quality were a significant source of variation in the additive model, and further research into using size spectra to monitor ecological quality in shallow lakes is warranted. Specifically, the production of size spectra from a wider range of sites is needed to provide greater statistical validation. 5. The use of size spectra can provide an attractive and cost-effective way for classifying lake ecosystems because it circumvents the need for difficult taxonomic description.
    • Assessment of biomarkers in Mytilus edulis to determine Good Environmental Status for implementation of MSFD in Ireland

      Giltrap, M.; Ronan, J.; Hardenberg, S.; Parkes, G.; McHugh, B.; McGovern, E.; Wilson, J.G. (Elsevier, 2013)
      Candidate OSPAR/ICES recommended biomarkers at the level of the individual in Mytilus edulis for determination of good environmental status for MSFD were evaluated against contaminant levels at sites around Ireland. The sites chosen ranged from moderate to low pollution levels, but the actual ranking of the sites varied according to the contaminant levels present. At the most contaminated site, Cork, 4 out of 16 contaminants exceeded the EAC, while at Shannon, no EACs were exceeded. The SOS assay suggested that Cork was the healthiest site with a LT50 of 17.6 days, while SOS for Shannon was 15.6 days. Likewise, condition factors varied among sites and did not always correspond to contaminant-based status. There may be uncertainty in assigning status around the not good:good boundary. This raises potential difficulties not only in the biomarker/contaminant load relationship but also in the reliability of the biomarkers themselves and hence barriers meeting compliance levels.
    • The Assessment of Irish Pelagic Species

      Molloy, J.; Mullins, E. (Marine Institute, 2001)
      The exploitation of pelagic species, particularly of herring and mackerel has for a long time been one of the most important components of the Irish fishing industry. Fisheries for both species have been responsible for the development of the very successful Irish pelagic fleet and also for the development of a very large processing industry in the Donegal area. The responsibility of assessing the stocks and providing management advice to the main Irish managing authority, The Department of the Marine and Natural Resources, lies with the Marine Fisheries Services Division (MFSD) of the Marine Institute. Both mackerel and herring have been continuously assessed since the 1960’s as a result of programmes carried out under the auspices of the International Council for the Exploration of the Sea (ICES) the international body that co-ordinates research and provides management advice to the EU. However, since the 1980’s both mackerel and herring stocks have been subjected to decreased total allowable catches (TACs) and decreased national quota and tighter management measures as a result of decreases in the stock sizes. This situation has forced the pelagic fleet, particularly that in the North west of Ireland to develop fisheries for alternative species so that it is not totally dependent on mackerel and herring. New fisheries have therefore developed for other pelagic species in recent years. Three species which are now exploited regularly are horse mackerel, (trachurus trachurus), also known as scad .or craig herring; blue whiting (Micromesistius poutassou) and Norwegian spring spawning herring (clupea harengus) also known as atlanto-scandian herring. When the fisheries for these species first developed there were no restrictions on catches for horse mackerel and blue whiting while catches on the Norwegian spring spawning herring were subject to an international agreement under which the EU was allowed a quota. None of these three species had previously been assessed by any Irish research project and the amount of scientific information was extremely limited. The international assessments carried out by ICES were based on poor data and had no input from Ireland. Ireland had for a number of years been taking significant catches of some species. The Processing Industry in Donegal were concerned that the lack of adequate biological sampling programmes could lead to inappropriate and inaccurate advice for the management of the stocks. This, it was felt, could have serious effects on the industry and would also demonstrate that Ireland had an irresponsible attitude to the development of these fisheries which was inconsistent with the Precautionary Approach to Fisheries Management. Therefore the Donegal Fish Merchants Association decided to co-operate with the Marine Institute to fund an initial biological sampling programmes on horse mackerel, blue whiting and Norwegian spring spawning herring and to make this data available to the relevant ICES Working Group. The objective of the sampling programme was to collect essential biological data necessary to expand the existing international programmes. In addition it was decided to provide an increased scientific input to existing MFSD assessment programmes such as the mackerel and horse mackerel tagging programmes, the international mackerel and horse mackerel egg surveys and the international blue whiting acoustic surveys. All the collected data has been submitted to the relevant ICES Assessment Working Groups from 1999 to 2001.
    • Azaspiracid Shellfish Poisoning: A Review on the Chemistry, Ecology, and Toxicology with an Emphasis on Human Health Impacts

      Twiner, M J; Rehmann, N; Hess, P; Doucette, G J (MDPI AG, 2008)
      Azaspiracids (AZA) are polyether marine toxins that accumulate in various shellfish species and have been associated with severe gastrointestinal human intoxications since 1995. This toxin class has since been reported from several countries, including Morocco and much of western Europe. A regulatory limit of 160 μg AZA/kg whole shellfish flesh was established by the EU in order to protect human health; however, in some cases, AZA concentrations far exceed the action level. Herein we discuss recent advances on the chemistry of various AZA analogs, review the ecology of AZAs, including the putative progenitor algal species, collectively interpret the in vitro and in vivo data on the toxicology of AZAs relating to human health issues, and outline the European legislature associated with AZAs.
    • Balanced harvesting can emerge from fishing decisions by individual fishers in a small-scale fishery

      Plank, Michael J; Kolding, Jeppe; Law, Richard; Gerritsen, Hans D; Reid, David (Wiley, 2016)
      Catching fish in proportion to their productivity, termed balanced harvesting, has been suggested as a basis for the ecosystem approach to fishing. Balanced harvesting has been criticized as uneconomical and unachievable because of the level of micromanagement it would require. Here, we investigate the consequences of allowing a fixed number of fishers in a small‐scale fishery to choose what size fish to attempt to catch. We examine this from a game‐theoretic perspective and test our predictions using an agent‐based model for fishers’ decisions coupled with a size‐spectrum model for the dynamics of a single fish species. We show that small‐scale gillnet fishers, operating without size‐based regulations, would end up catching small and large fish in proportion to their productivity, in other words balanced harvesting. This is significant because it shows that, far from being unachievable, balanced harvesting can emerge without external intervention under some circumstances. Controls are needed to prevent overfishing, but minimum size regulations alone are not sufficient to achieve this, and actually reduce the sustainable yield by confining fishing to a relatively unproductive part of the size‐spectrum. Our findings are particularly relevant for small‐scale fisheries in areas where there is poverty and malnutrition because here provision of biomass for food is more important than the market value of the catch.
    • Balancing selection on MHC class I in wild brown trout Salmo trutta

      O'Farrell, B; Dennis, C; Benzie, JA; McGinnity, P; Carlsson, J; De Eyto, E; Coughlan, J; Igoe, F; Meehan, R; Cross, T (Wiley, 2012-09)
      Evidence is reported for balancing selection acting on variation at major histocompatibility complex (MHC) in wild populations of brown trout Salmo trutta. First, variation at an MHC class I (satr-uba)–linked microsatellite locus (mhc1) is retained in small S. trutta populations isolated above waterfalls although variation is lost at neutral microsatellite markers. Second, populations across several catchments are less differentiated at mhc1 than at neutral markers, as predicted by theory. The population structure of these fish was also elucidated.
    • Bayesian survey-based assessment of North Sea plaice (Pleuronectes platessa): extracting integrated signals from multiple surveys

      Bogaards, J A; Kraak, S B M; Rijnsdorp, A D (Oxford University Press, 2009)
      Dependence on a relatively small sample size is generally viewed as a big disadvantage for survey-based assessments. We propose an integrated catch-at-age model for research vessel data derived from multiple surveys, and illustrate its utility in estimating trends in North Sea plaice abundance and fishing mortality. Parameter estimates were obtained by Bayesian analysis, which allows for estimation of uncertainty in model parameters attributable to measurement error. Model results indicated constant fishing selectivity over the distribution area of the North Sea plaice stock, with decreased selectivity at older age. Whereas separate analyses of survey datasets suggested different biomass trends in the southeast than in the western and central North Sea, a combined analysis demonstrated that the observations in both subareas were compatible and that SSB has been increasing over the period 1996- 2005. The annual proportion of fish that dispersed in a northwesterly direction was estimated to increase from about 10% at age 2 to 33% at age 5 and older. We also found higher fishing mortality rates than reported in ICES assessments, which could be the consequence of inadequate specification of catchability-at-age in this study or underestimated fishing mortality by the conventional ICES assessment, which relies on official landings figures.
    • Biased stock assessment when using multiple, hardly overlapping, tuning series if fishing trends vary spatially

      Kraak, S B M; Daan, N; Pastoors, M A (Oxford University Press, 2009)
      Fishing-effort distributions are subject to change, for autonomous reasons and in response to management regulations. Ignoring such changes in a stock-assessment procedure may lead to a biased perception. We simulated a stock distributed over two regions with inter-regional migration and different trends in exploitation, and tested the performance of Extended Survivors Analysis (XSA) and a statistical catch-at-age model in terms of bias, when spatially restricted tuning series were applied. If we used a single tuning index that covered only the more heavily fished region, estimates of fishing mortality and spawning-stock biomass were seriously biased. If two tuning series each exclusively covering one region were used (without overlap but together covering the whole area), estimates were also biased. Surprisingly, a moderate degree of overlap of spatial coverage of the two tuning indices was sufficient to reduce bias of the XSA assessment substantially. However, performance was best when one tuning series covered the entire stock area.
    • Bioactive agents from marine mussels and their effects on human health

      Grienke, U.; Silke, J.; Tasdemir, D. (Elsevier, 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
    • Biosensors for the monitoring of harmful algal blooms

      McPartlin, D. A.; Loftus, J. H.; Crawley, A. S.; Silke, J.; Murphy, C. S.; O’Kennedy, R. J. (Elsevier, 2017)
      Harmful algal blooms (HABs) are a major global concern due to their propensity to cause environmental damage, healthcare issues and economic losses. In particular, the presence of toxic phytoplankton is a cause for concern. Current HAB monitoring programs often involve laborious laboratory-based analysis at a high cost and with long turnaround times. The latter also hampers the potential to develop accurate and reliable models that can predict HAB occurrence. However, a promising solution for this issue may be in the form of remotely deployed biosensors, which can rapidly and continuously measure algal and toxin levels at the point-of-need (PON), at a low cost. This review summarises the issues HABs present, how they are difficult to monitor and recently developed biosensors that may improve HAB-monitoring challenges.
    • Biotic response to forest harvesting in acidic blanket peat fed streams: a case study from Ireland

      O'Driscoll, Connie; de Eyto, Elvira; Rodgers, Michael; O'Connor, Mark; Asam, Zaki-ul-Zaman; Xiao, Liwen (Elsevier, 2013)
      Blanket peat catchments are important biodiversity refugia and are increasingly recognised for their role in regional carbon and water balances. A key pressure on these catchments is forest clearfelling which increases stream phosphorus potentially leading to eutrophication. However, these unique systems are underrepresented in the development of bioassessment monitoring programmes and so are at risk to impacts. In this study, a multiple before-after-control-impact (MBACI) study was designed in three neighbouring peatland catchments and provided a unique opportunity to assess the impact of forest clearfelling events on macroinvertebrate and phytobenthic assemblages. Statistical analysis revealed substantial differences in the macroinvertebrate assemblages after clearfelling with higher abundances of chironomids. Macroinvertebrate derived indices EPT, diversity and species richness were significantly reduced. This was accompanied by a shift in functional feeding group representation away from shredders and collector–filterers to a dominance of collector–gatherers after clearfelling. In contrast, forest clearfelling did not significantly impact the diatom assemblages and diatom derived indices remained static for the duration of the study period.
    • Boarfish (Capros aper) target strength modelled from magnetic resonance imaging (MRI) scans of its swimbladder

      Fassler, S.; O'Donnell, C.; Jech, J. (International Council for the Exploration of the Sea (ICES), 2013)
      Boarfish (Capros aper) abundance has increased dramatically in the Northeast Atlantic from the early 1970s after successive years of good recruitment attributed to an increase in sea surface temperature. Due to increased commercial fishing over recent years, an acoustic boarfish survey funded by the Killybegs Fishermen's Organisation was initiated by the Marine Institute to establish a baseline for the future management of this stock. In the absence of any species-specific boarfish target strength (TS), acoustic backscatter was estimated by a Kirchhoff-ray mode model using reconstructed three-dimensional swimbladder shapes which were computed from magnetic resonance imaging scans of whole fish. The model predicted TS as a function of size, fish tilt angle, and operating frequency. Standardized directivity patterns revealed the increasing importance of changes in the inclination of the dorsal swimbladder surface at higher frequencies (120 and 200 kHz) and a less directive response at lower frequencies (18 and 38 kHz). The model predicted a TS-to-total fish length relationship of TS = 20 log10(L) − 66.2. The intercept is ∼1 dB higher than in the general physoclist relationship, potentially reflecting the bulky nature of the boarfish swimbladder with its relatively large circumference.
    • Certified Reference Materials for Marine Monitoring

      Pellizzato, Francesca; McGovern, Evin; Quevauviller, Philippe (J. Wiley & Sons, Chichester, West Sussex, 2011)
    • Chemical aspects of ocean acidification monitoring in the ICES marine area.

      Hydes, D.J.; McGovern, E.; Walsham, P. (International Council for the Exploration of the Sea, 2013)
      It is estimated that oceans absorb approximately a quarter of the total anthropogenic releases of carbon dioxide to the atmosphere each year. This is leading to acidification of the oceans, which has already been observed through direct measurements. These changes in the ocean carbon system are a cause for concern for the future health of marine ecosystems. A coordinated ocean acidification (OA) monitoring programme is needed that integrates physical, biogeochemical, and biological measurements to concurrently observe the variability and trends in ocean carbon chemistry and evaluate species and ecosystems response to these changes. This report arises from an OSPAR request to ICES for advice on this matter. It considers the approach and tools available to achieve coordinated monitoring of changes in the carbon system in the ICES marine area, i.e. the Northeast Atlantic and Baltic Sea.