Griffiths A.M.,University of Exeter |
Griffiths A.M.,Marine Biological Association of The United Kingdom |
Machado-Schiaffino G.,University of Oviedo |
Dillane E.,University College Cork |
And 13 more authors.
BMC Genetics | Year: 2010
Background: Anadromous migratory fish species such as Atlantic salmon (Salmo salar) have significant economic, cultural and ecological importance, but present a complex case for management and conservation due to the range of their migration. Atlantic salmon exist in rivers across the North Atlantic, returning to their river of birth with a high degree of accuracy; however, despite continuing efforts and improvements in in-river conservation, they are in steep decline across their range. Salmon from rivers across Europe migrate along similar routes, where they have, historically, been subject to commercial netting. This mixed stock exploitation has the potential to devastate weak and declining populations where they are exploited indiscriminately. Despite various tagging and marking studies, the effect of marine exploitation and the marine element of the salmon lifecycle in general, remain the "black-box" of salmon management. In a number of Pacific salmonid species and in several regions within the range of the Atlantic salmon, genetic stock identification and mixed stock analysis have been used successfully to quantify exploitation rates and identify the natal origins of fish outside their home waters - to date this has not been attempted for Atlantic salmon in the south of their European range.Results: To facilitate mixed stock analysis (MSA) of Atlantic salmon, we have produced a baseline of genetic data for salmon populations originating from the largest rivers from Spain to northern Scotland, a region in which declines have been particularly marked. Using 12 microsatellites, 3,730 individual fish from 57 river catchments have been genotyped. Detailed patterns of population genetic diversity of Atlantic salmon at a sub-continent-wide level have been evaluated, demonstrating the existence of regional genetic signatures. Critically, these appear to be independent of more commonly recognised terrestrial biogeographical and political boundaries, allowing reporting regions to be defined. The implications of these results on the accuracy of MSA are evaluated and indicate that the success of MSA is not uniform across the range studied; our findings indicate large differences in the relative accuracy of stock composition estimates and MSA apportioning across the geographical range of the study, with a much higher degree of accuracy achieved when assigning and apportioning to populations in the south of the area studied. This result probably reflects the more genetically distinct nature of populations in the database from Spain, northwest France and southern England. Genetic stock identification has been undertaken and validation of the baseline microsatellite dataset with rod-and-line and estuary net fisheries of known origin has produced realistic estimates of stock composition at a regional scale.Conclusions: This southern European database and supporting phylogeographic and mixed-stock analyses of net samples provide a unique tool for Atlantic salmon research and management, in both their natal rivers and the marine environment. However, the success of MSA is not uniform across the area studied, with large differences in the relative accuracy of stock composition estimates and MSA apportioning, with a much higher degree of accuracy achieved when assigning and apportioning to populations in the south of the region. More broadly, this study provides a basis for long-term salmon management across the region and confirms the value of this genetic approach for fisheries management of anadromous species. © 2010 Griffiths et al; licensee BioMed Central Ltd.
Haynes P.S.,Mayo Institute of Technology, Galway |
Brophy D.,Mayo Institute of Technology, Galway |
McGrath D.,Mayo Institute of Technology, Galway |
O'Callaghan R.,Central Fisheries Board |
And 2 more authors.
Journal of Sea Research | Year: 2010
Turbot (Psetta maxima Linnaeus) is a high value commercially exploited marine flatfish which occurs in European waters, from the Northeast Atlantic to the Arctic Circle, the Baltic and Mediterranean Sea. In Ireland, turbot are the most valuable commercial non-quota species. Very little is known about their population dynamics in the wild, in particular during the sandy beach nursery phase of the life history. In 2000, a survey was established to assess flatfish species on nursery grounds on the west coast of Ireland. Eleven sandy beaches were assessed for 0+ turbot by beach seining, over an eight year period (2000-2007) during the months of August and September. The objective of the study was to estimate juvenile turbot abundance and size structure to determine if any spatial and annual trends existed. Large scale variability in the recruitment of fish to nursery grounds may be indicative of fluctuations in the adult stock. Turbot were found to recruit to five beaches consistently over the eight year period. Temporal and spatial variability in the relative abundance and length of turbot was discerned, with no apparent overall trend. However, certain nursery grounds were shown in most of the years examined to support higher abundances of turbot in comparison to other areas over the eight year period. Turbot abundances on nursery grounds were significantly correlated with mean spring sea temperatures during the pelagic stage. The condition of turbot did not significantly differ on an annual or spatial scale. Mean densities of 0+ turbot along the Irish coast were found to be similar and at times higher than other areas in Europe, ranging from 0.1 (±0.3) individuals 1000m-2 to 18.5 (±6.9) individuals 1000m-2. Mean turbot total length on beaches ranged from 3.8cm (±0.6) to 6.6cm (±4.3). The observed spatial and temporal variability in abundance and length highlights the need for long-term studies when assessing juvenile flatfish populations. Results from the present study have provided much needed baseline data on wild juvenile turbot populations which is severely lacking for this species both on an Irish and on a European scale. © 2010 Elsevier B.V.
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: ENV.2007.2.2.1.2. | Award Amount: 4.11M | Year: 2008
Eels play an important socioeconomic and ecological role in many European countries. Recruitment failure has contributed to a halving of catches from 40,000t in the last three decades to less than 20,000t today. The EUs Eel Recovery Plan aims to maximize silver eel production and escapement to the sea to maintain the stocks reproductive potential. However, very little is known about the contribution of eels of different European river systems to successful recruitment because almost nothing is known about the life of silver eels once they escape to the sea. We propose a research initiative to investigate the ecology and environmental dependencies of European eels during their spawning migration. Archival tags that detach from their eel hosts and communicate stored data via satellite will be used to determine migration routes, migration success and habitat preferences of different stock components. The information will be integrated with studies on eels in riverine and estuarine habitats, and leading edge biochemical techniques, to determine the most important eel habitats to conserve to enhance and conserve eel stocks in the UK and across Europe
Massa-Gallucci A.,University College Dublin |
Coscia I.,University College Dublin |
O'Grady M.,Central Fisheries Board |
Kelly-Quinn M.,University College Dublin |
Mariani S.,University College Dublin
Conservation Genetics | Year: 2010
One main challenge in conservation biology is to preserve genetic variability and adaptive variation within and among populations. However, constant anthropogenic habitat modifications have severe effects on the evolutionary dynamics shaping wild populations and pose a serious threat to the natural evolution of biodiversity. The aim of the present study was to unravel the genetic structuring of brown trout (Salmo trutta) populations in the largest freshwater catchment in Ireland, whose habitats have experienced major human-mediated changes over at least two centuries. A total of 419 juvenile fish were sampled from nine main rivers in the Corrib catchment and were genotyped using 12 microsatellites. Both Bayesian clustering and F ST-based analyses of genetic variance sorted these populations into five main genetically distinct groups, characterized by different extent of genetic differentiation among populations. These groups were also characterized by some degree of admixture, which can be partly explained by recent gene flow. Overall, the study suggests that the Corrib trout may conform to a metapopulation model with local populations that show different degrees of isolation and are interconnected by various level of gene flow. Results add further insights into metapopulation evolutionary dynamics and provide a useful basis to implement appropriate conservation strategies. © 2010 Springer Science+Business Media B.V.
Harrison A.J.,Central Fisheries Board |
Kelly F.L.,Central Fisheries Board |
Rosell R.S.,Agri Food and Biosciences Institute |
Champ T.W.S.,Central Fisheries Board |
And 2 more authors.
Biology and Environment | Year: 2010
The Irish Pollan Coregonus autumnalis Pallas is unique in western Europe, with its current known distribution being limited to four lakes in Ireland; Lough Neagh and Lower Lough Erne in Northern Ireland and Lough Ree and Lough Derg in the Republic of Ireland. In this paper we report the first authenticated record of pollan in a fifth Irish lake-Lough Allen, County Leitrim. Using hydroacoustic technology, combined with a ground-truth gill netting survey, abundance estimates show that the population is relatively small, numbering in the region of several thousand individuals. Captured fish ranged in age from 1+ to 4+, indicating reproductive success in each year over the previous four years. Threats to sensitive species such as pollan include eutrophication, competition with introduced species, land drainage and the resulting siltation of downstream lakes. Further detailed investigations on the status of this newly discovered population, including location of spawning sites, recruitment success and genetic relationship with other Irish populations, are crucial in informing management decisions with a view to protecting this unique and threatened fish species. © Royal Irish Academy.
Coscia I.,University College Dublin |
Rountree V.,University College Dublin |
King J.J.,Central Fisheries Board |
Roche W.K.,Central Fisheries Board |
Mariani S.,University College Dublin
Journal of Fish Biology | Year: 2010
Meristic identification, mitochondrial DNA and a suite of microsatellite markers were employed to estimate the incidence of hybridization in wild populations of anadromous Allis shad Alosa alosa and twaite shad Alosa fallax in southern Irish riverine and estuarine waters. It was shown that 16% of the fishes examined were misclassified using meristic count of gill rakers. Next, a significant proportion of fishes that were robustly assigned to a species using nuclear markers were shown to possess the mtDNA of the other. The genomes of A. alosa and A. fallax in Ireland are extensively introgressed, which suggests a complex history of hybridization between these species, which can only partially be explained by recent man-made habitat changes. © 2010 The Authors. Journal compilation © 2010 The Fisheries Society of the British Isles.
Hawkins C.J.,National University of Ireland |
Caffrey J.M.,Central Fisheries Board |
Stuart P.,National University of Ireland |
Lawton C.,National University of Ireland
Parasitology Research | Year: 2010
Native Eurasian otter (Lutra lutra) and introduced American mink (Mustela vison) carcasses collected throughout Ireland were screened for biliary parasites. Secondary intermediate hosts, Cyprinid fish, were also examined for Opistorchiid metacercariae. Twenty-nine mink and 24 otter gall bladders were screened for biliary parasites. A single mink and three otters were found to be infected with the digenetic trematode Pseudamphistomum truncatum. Eighty-nine percent of roach (Rutilus rutilus) from the River Shannon were infected with P. truncatum metacercariae, confirming the persistence of the parasite. This is the first record of the species in Ireland, and its recent introduction is probably related to the movement and release of Cyprinid fishes by anglers. © 2010 Springer-Verlag.
Reynolds J.D.,Trinity College Dublin |
Lynn D.,National Parks and Wildlife Service |
O'Keeffe C.,National Parks and Wildlife Service |
Lucey J.,U.S. Environmental Protection Agency |
And 3 more authors.
Freshwater Crayfish | Year: 2010
Lhe white-clawed crayfish, Austropotamobius pallipes (Lereboullet), is the only crayfish species in Ireland. The Irish population is unique in the EU in not having alien species overlapping in its range. Austropotamobius pallipes is protected under the EU Habitats Directive [92/43/EEC], which requires a standardized periodic assessment of its current status. The first assessment was carried out in 2007, and involved updating a database of all historic records, and comparing this with a new database of current records. While A. pallipes is still widespread in Ireland, there was a significant decline in its natural range. The species conservation status was assessed as "Unfavourable inadequate" due to this decline in range. © 2010 International Association of Astacology.
Caffrey J.M.,Central Fisheries Board |
Millane M.,Central Fisheries Board |
Evers S.,Central Fisheries Board |
Moran H.,Central Fisheries Board |
Butler M.,Western Regional Fisheries Board
Aquatic Invasions | Year: 2010
This technical paper presents results from pilot field trials conducted on the novel use of a biodegradable jute material to eradicate the highly invasive aquatic macrophyte Lagarosiphon major Ridley from Lough Corrib, Ireland. The results demonstrate the ability of the jute material to comprehensively kill L. major and to restore native macrophyte communities to areas of the lake that were previously overgrown with this priority invasive species. To date, eight indigenous plant species (four charophytes and four angiosperms) have been recorded growing through the loose-weave jute fabric. However, no Lagarosiphon has been recorded as doing so. This material has the potential for broader application in the management of nuisance aquatic weeds and in the restoration of native flora extirpated by these alien species. © 2010 The Author(s).