Eliasen S.Q.,University of Aalborg |
Papadopoulou K.-N.,Hellenic Center for Marine Research |
Vassilopoulou V.,Hellenic Center for Marine Research |
ICES Journal of Marine Science | Year: 2014
Discard of unwanted catches are common in European fisheries, but reducing or banning this has been given high priority in the proposal for the reform of the Common Fisheries Policy. Although many technical regulations have been introduced to limit unwanted catches, there is little understanding of the underlying socio-economic and institutional incentives causing discard at the fisher level. The paper presents an approach which views discards as a result of decisions made both on deck and at earlier stages of the fishing planning and implementation process. Decisions made by fishers resulting in a more selective fishery are considered selective behaviour. It is argued that fishing practices are institutionally embedded within three institutional spheres: state, market, and community, which together with natural conditions create incentives and frameworks for discard and selective behaviour. A comprehensive list of factors which may influence discards and selective behaviour is developed and applied to three case studies-all trawl fisheries-in Denmark, Greece, and England. The paper discusses cross-case findings of how the identified factors may create drivers for discard. Finally, a refined list of factors is presented in a tree structure and the usefulness of the list as a tool for analysing drivers for discard and selective behaviour, in a context of developing mitigating measures, is discussed. © 2014 International Council for the Exploration of the Sea. All rights reserved.
Mirbahai L.,University of Birmingham |
Yin G.,BGI Shenzhen |
Bignell J.P.,Cefas |
Li N.,BGI Shenzhen |
And 2 more authors.
Epigenetics | Year: 2011
The link between environment, alteration in DNA methylation and cancer has been well established in humans; yet, it is under-studied in unsequenced non-model organisms. The occurrence of liver tumors in the flatfish dab collected at certain UK sampling sites exceeds 20%, yet the causative agents and the molecular mechanisms of tumor formation are not known, especially regarding the balance between epigenetic and genetic factors. Methylated DNA Immunoprecipitation (MeDIP) combined with de novo high-throughput DNA sequencing were used to investigate DNA methylation changes in dab hepatocellular adenoma tumors for the first time in an unsequenced species. Novel custommade dab gene expression arrays were designed and used to determine the relationship between DNA methylation and gene expression. In addition, the confirmatory techniques of bisulfite sequencing PCR (BSP) and RT-PCR were applied. Genes involved in pathways related to cancer, including apoptosis, wnt/β-catenin signaling and genomic and nongenomic estrogen responses, were altered both in methylation and transcription. Global methylation was statistically significantly 1.8-fold reduced in hepatocellular adenoma and non-cancerous surrounding tissues compared with liver from non-cancer bearing dab. Based on the identified changes and chemical exposure data, our study supports the epigenetic model of cancer. We hypothesize that chronic exposure to a mixture of environmental contaminants contributes to a global hypomethylation followed by further epigenetic and genomic changes. The findings suggest a link between environment, epigenetics and cancer in fish tumors in the wild and show the utility of this methodology for studies in non-model organisms. © 2011 Landes Bioscience.
Heymans J.J.,Scottish Association for Marine Science |
Mackinson S.,Cefas |
Sumaila U.R.,Fisheries Center |
Dyck A.,Fisheries Center |
And 2 more authors.
PLoS ONE | Year: 2011
Background: This study examines the impact of subsidies on the profitability and ecological stability of the North Sea fisheries over the past 20 years. It shows the negative impact that subsidies can have on both the biomass of important fish species and the possible profit from fisheries. The study includes subsidies in an ecosystem model of the North Sea and examines the possible effects of eliminating fishery subsidies. Methodology/Principal Findings: Hindcast analysis between 1991 and 2003 indicates that subsidies reduced the profitability of the fishery even though gross revenue might have been high for specific fisheries sectors. Simulations seeking to maximise the total revenue between 2004 and 2010 suggest that this can be achieved by increasing the effort of Nephrops trawlers, beam trawlers, and the pelagic trawl-and-seine fleet, while reducing the effort of demersal trawlers. Simulations show that ecological stability can be realised by reducing the effort of the beam trawlers, Nephrops trawlers, pelagic- and demersal trawl-and-seine fleets. This analysis also shows that when subsidies are included, effort will always be higher for all fleets, because it effectively reduces the cost of fishing. Conclusions/Significance: The study found that while removing subsidies might reduce the total catch and revenue, it increases the overall profitability of the fishery and the total biomass of commercially important species. For example, cod, haddock, herring and plaice biomass increased over the simulation when optimising for profit, and when optimising for ecological stability, the biomass for cod, plaice and sole also increased. When subsidies are eliminated, the study shows that rather than forcing those involved in the fishery into the red, fisheries become more profitable, despite a decrease in total revenue due to a loss of subsidies from the government. © 2011 Heymans et al.
News Article | December 21, 2016
The aim of the framework contract is to provide the European Commission the scientific advice they need in order to ensure the sustainable management of EU fisheries outside EU waters, which are managed by international fishery management organisation. The provision of scientific advice will especially focus on the External Dimension of the Common Fisheries Policy (excluding the Mediterranean Sea and the Black Sea). The advice and services required by the European Commission will support the implementation of the Common Fisheries Policy (CFP), especially the external policy, by applying the precautionary approach and focusing on safeguarding the entire ecosystem, and ensuring that the EU environmental laws (Marine Strategy Framework Directive) and the Integrated Maritime Policy are complied with. The EUR 4M budget for the framework contract is funded by the EU via the European Maritime and Fisheries Fund. Other organisations that are part of the consortium led by AZTI include Institut national supérieur des sciences agronomiques, agroalimentaires, horticoles et du paysage (AGROCAMPUS OUEST); Centre for Environment, Fisheries and Aquaculture Science (CEFAS); Spanish Institute of Oceanography (IEO); Institute for Marine Resources & Ecosystem Studies (IMARES); Instituto Português do Mar e da Atmosfera, I.P. (IPMA); Institut de Recherche pour le Développement (IRD); and MRAG Limited (MRAG).
Hoving H.-J.T.,Leibniz Institute of Marine Science |
Laptikhovsky V.V.,CEFAS |
Robison B.H.,Monterey Bay Aquarium Research Institute
Current Biology | Year: 2015
Summary Coleoid cephalopods are thought to go through only one reproductive cycle in their life. We here report that vampire squid (Vampyroteuthis infernalis) show evidence of multiple reproductive cycles. Female vampire squid spawn their eggs, then return to a resting reproductive state, which is followed by the development of a new batch of eggs. This reproductive cycle is likely to be repeated more than twenty times. This combination of reproductive traits is different from that of any other extant coleoid cephalopod. © 2015 Elsevier Ltd All rights reserved.
Tidd A.N.,Cefas |
Hutton T.,CSIRO |
Kell L.T.,ICCAT Secretariat |
ICES Journal of Marine Science | Year: 2011
A profitable fishery attracts additional effort (vessels enter), eventually leading to overcapacity and less profit. Similarly, fishing vessels exit depending on their economic viability (or reduced expectations of future benefits) or encouraged by schemes such as decommissioning grants and/or when there is consolidation of fishing effort within a tradable rights-based quota system (e.g. individual transferable quotas). The strategic decision-making behaviour of fishers in entering or exiting the English North Sea beam trawl fishery is analysed using a discrete choice model by integrating data on vessel characteristics with available cost data, decommissioning grant information, and other factors that potentially influence anticipated benefits or future risks. It is then possible to predict whether operators choose to enter, stay, exit, or decommission. Important factors affecting investment include vessel age and size, future revenues, operating costs (e.g. fuel), stock status of the main target species, and the impact of management measures (e.g. total allowable catches) and total fleet size (a proxy for congestion). Based on the results, the predicted marginal effects of each factor are presented and the impact of each is discussed in the context of policies developed to align fleet capacity with fishing opportunities. ©  Crown copyright.
Nascimento S.M.,State University of Norte Fluminense |
Correa E.V.,State University of Norte Fluminense |
Menezes M.,Federal University of Rio de Janeiro |
Varela D.,University of Los Lagos |
And 2 more authors.
Harmful Algae | Year: 2012
Since 1998, blooms of the epi-benthic dinoflagellate, Ostreopsis cf. ovata Fukuyo have been reported in the Arraial do Cabo area, Rio de Janeiro, Brazil. This dinoflagellate can produce one of the most lethal marine toxins, palytoxin (PLTX) and its analogues. In the study reported herein, the growth rate, cellular dimensions and toxin profile of two O. cf. ovata strains isolated from Armação dos Búzios, Rio de Janeiro were investigated. Molecular analysis (5.8S rDNA gene and ITS regions) of one strain was also performed. Respectively, strains LCA-E7 and LCA-B7 showed growth rates of 0.15 and 0.10divday -1, and cell dimensions of the strains and field population were similar to those found for O. ovata from the Mediterranean Sea. Ribosomal DNA genetic sequences obtained from the nuclear region (ITSs and 5.8S) of strain LCA-E7 confirmed that this is O. cf. ovata and grouped this isolate in a robust clade with isolates from Brazil and the Mediterranean. The production of putative (p)PLTX and ovatoxin (OVTX) was assessed using ouabain inhibited hemolytic assays. Extracts of the two strains caused hemolysis and was positively related to O. cf. ovata cell numbers. Analysis by liquid chromatography tandem mass spectrometry identified OVTX-a, -b, -c, -d and -e. Estimated concentrations varied between 20 and 171pg[OVTX-a]cell -1, 23 and 205pg[OVTX-b]cell -1, 3 and 37pg[OVTX-c]cell -1 and 3 and 80pg[OVTX-d+e]cell -1. OVTX-a and -b were the major components of the toxin profile produced by strains LCA-E7 and LCA-B7 and represented between 45 and 95% of the total OVTX+pPLTX content of these cells. Concentrations of OVTXs produced by the Brazilian strains were higher than those found in an O. cf. ovata Adriatic isolate, although in the same magnitude. © 2011 Elsevier B.V.
Fisheries Management and Ecology | Year: 2013
Since the Common Fisheries Policy reform in 2002, there have been various proposals for designing effective input-management tools in the context of demersal multispecies and multimétier fisheries to augment quota management. The relationship between fishing mortality and effort exerted by the English beam trawl fleet is investigated for two stocks of North Sea demersal fish, plaice, Pleuronectes platessa L., and sole, Solea solea (L.). Catchability was adjusted by accounting for targeting by this gear, seasonal and area effects, and individual vessel variation, using results from a generalised linear mixed-effects model (GLMM) that included random effects (in this case, vessel). Descriptors were standardised in relation to distinct submétiers and their impact on both species. Fishing efficiency was calculated as the ratio between relative nominal landings per unit effort derived from the GLMM and survey indices from a standard survey vessel. Fishing efficiency for sole increased (+0.6% annually) and for plaice decreased (-6.2%), likely because of changes in targeting, fuel costs and regulations. © 2013 Crown.
van der Molen J.,Cefas |
Smith H.C.M.,University of Exeter |
Lepper P.,Loughborough University |
Limpenny S.,Cefas |
Continental Shelf Research | Year: 2014
Three models were applied to obtaina first assessment of some of the potential impacts of large-scale operational wind turbine arrays on the marine ecosystem in a well-mixed area in a shelf sea: a biogeochemical model,a wave propagation model and an a coustic energy flux model.The results of the models are discussed separately and together to elucidate the combined effects. Overall,all three models suggested relatively weak environmental changes for the mechanisms included in this study, however these are only a subset of all the potential impacts,and a number of assumptions had to be made. Further work is required to address these assumptions and additional mechanisms. All three models suggested most of the changes with in the wind turbine array,and small changes up to several tens of km outside the array. Within the array, the acoustic model indicated the most concentrated, spatially repetitive changes to the environment,followed by the SWAN wave model,and the biogeochemical model being the most diffuse. Because of the different spatial scales of the response of the three models,the combined results suggested a spectrum of combinations of environmental changes with in the wind turbine array that marine organism smight respond to. The SWAN wave model and the acoustic model suggested a reduction in changes with increasing distance between turbines. The SWAN wave model suggested that the biogeochemical model, because of the in ability of its simple wave model to simulate wave propagation,over-estimated the biogeochemical changes by a factor of 2 or more. The biogeochemical model suggested that the benthic system was more sensitive to the environmental changes than the pelagic system. © 2014 Published by Elsevier Ltd.
Tidd A.N.,Cefas |
Hutton T.,CSIRO |
Kell L.T.,ICCAT Secretariat |
Blanchard J.L.,University of Sheffield |
Blanchard J.L.,Imperial College London
Fisheries Research | Year: 2012
A discrete choice model is applied to determine how fishing effort is allocated spatially and temporally by the English and Welsh North Sea beam trawl fleet. Individual vessels can fish in five distinct areas, and the utility of fishing in an area depends on expected revenue measured as previous success (value per unit effort) and experience (past fishing effort allocation), as well as perceived costs (measured as distance to landing port weighted by fuel price). The model predicts fisher location choice, and the predictions are evaluated using iterative partial cross validation by fitting the model over a series of separate time-periods (nine separate time-periods). Results show the relative importance of the different drivers that change over time. They indicate that there are three main drivers throughout the study, past annual effort, past monthly effort in the year of fishing, and fuel price, largely reflecting the fact that previous practices where success was gained are learned (i.e. experience) and become habitual, and that seasonal variations also dominate behaviour in terms of the strong monthly trends and variable costs. In order to provide an indication of the model's predictive capabilities, a simulated closure of one of the study areas was undertaken (an area that mapped reasonably well with the North Sea cod 2001 partial closure of the North Sea for 10 weeks of that year). The predicted reallocation of effort was compared against realized/observed reallocation of effort, and there was good correlation at the trip level, with a maximum 10% misallocation of predicted effort for that year. © 2012.