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Registros recuperados: 111 | |
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Mahe, Kelig; Elleboode, Romain; Persohn, Cecile; Dufour, Jean-louis. |
Age and growth of lemon sole (Microstomus kitt) were determined from 115 specimens collected in the Celtic Sea and in the North Sea in 2006 and 2007. Total length is ranged from 11 to 44 cm, while total weight varied between 12 and 1040 g. Age estimation was based on otoliths readings. The oldest male and female were estimated to be 9 years old. The length–weight relationships parameters for lemon sole in the Celtic Sea and in the North Sea were W=0.0043*TL3.2860 and W=0.0062*TL3.1505 respectively. Weight including both sexes increased with positive allometric growth. The von Bertalanffy growth equation in the North Sea was fitted on the basis of mean length-at-age data resulting in parameters values of TL∞ = 36.44 cm (S.E. = 0.484), K = 0.187 /y (S.E. =... |
Tipo: Text |
Palavras-chave: Lemon sole; Growth; Von Bertalanffy; Celtic Sea; North Sea. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00019/13024/10002.pdf |
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Leonardi, Sophie; Rubin, Alex; Meillat, Marc; Coppin, Franck; Delpech, Jean-paul; Morandeau, Fabien; Larnaud, Pascal. |
Ce rapport fait la synthèse des travaux réalisés en 2008 et en 2009 au cours du programme Selecmer. Celui-ci, réalisé à l'initiative des professionnels de la pêche en partenariat avec l'Ifremer, avait pour objectif de travailler à améliorer la sélectivité du chalut de fond qu'ils utilisent afin de diminuer les rejets des individus hors-tailles1, en particulier pour le merlan, tout en limitant les pertes commerciales immédiates. Une première phase a consisté à tester l'efficacité de fenêtres à mailles carrées. La deuxième phase a eu pour objectif de développer une grille sélective. Des essais en bassin et des campagnes vidéo en mer ont permis d'apporter des ajustements aux dispositifs sélectifs. L'ensemble des essais de sélectivité à bord des navires de... |
Tipo: Text |
Palavras-chave: Professional fishermen; Square mehs; Flume tank; Selective grid; North Sea; Channel; Bottom trawl; Selectivity; Fishing; Professionnels; Mailles carrées; Campagnes à la mer; Bassin d'essais; Grille sélective; Mer du Nord; Manche; Chalut de fond; Sélectivité; Pêche. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/rapport-6776.pdf |
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Kell, L; Pilling, G; Kirkwood, G; Pastoors, M; Mesnil, Benoit; Korsbrekke, K; Abaunza, P; Aps, R; Biseau, Alain; Kunzlik, P; Needle, C; Roel, B; Ulrich, Clara. |
Current scientific management objectives for ICES roundfish stocks are to ensure conservation of the biological resource and do not explicitly consider economic or social objectives. For example, there are currently no objectives to maximize the sustainable yield or to reduce variability in total allowable catches (TACs). This is despite the fact that the current system can result in wide annual fluctuations in TAC, limiting the ability of the fishing industry to plan for the future. Therefore, this study evaluated management strategies that stabilized catches by setting bounds on the interannual variability in TACs. An integrated modelling framework was used, which simulated both the real and observed systems and the interactions between system... |
Tipo: Text |
Palavras-chave: Whiting; TAC; Simulation; Saithe; Population modelling; North Sea; Management; Limiting variations; Harvest strategies; Hake; Haddock; Evaluation; Cod; Bounds. |
Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/2006/publication-3694.pdf |
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Petitgas, Pierre; Alheit, Juergen; Peck, Myron A.; Raab, Kristina; Irigoien, Xabier; Huret, Martin; Van Der Kooij, Jeroen; Pohlmann, Thomas; Wagner, Carola; Zarraonaindia, Iratxe; Dickey-collas, Mark. |
The abundance and spatial occupation of European anchovy Engraulis encrasicolus have increased in the North Sea since the mid-1990s. We use a cross-disciplinary approach combining genetics, transport modelling, survey time series analyses and physical oceanographic modelling to investigate 3 hypotheses on the reasons for this change. Evidence from connectivity studies suggests that the population of North Sea anchovy is separate from that in the Bay of Biscay. The recruitment pulses observed in survey data fit a life cycle which includes spawning in early summer and larval development in late summer. This also supports the concept of population expansion originating from local remnant population(s). In terms of growth physiology, suitable thermal windows... |
Tipo: Text |
Palavras-chave: Climate variability; Small pelagic fish; Regime shift; Temperature; Anchovy; North Sea. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00060/17140/14638.pdf |
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Marchal, Paul; Ulrich, Clara; Pastoors, M. |
The scope of this study is to investigate the extent to which area-based management may have influenced the fishing efficiency of the Danish and Dutch demersal fleets harvesting cod, plaice and sole in the North Sea. Special consideration is given to the 'plaice box', a restricted area where fishing is prohibited to towed-gear fleets of horsepower exceeding 300 hp. An index of fishing power is calculated as the log-ratio between the catch per unit effort (CPUE) of any vessel and some survey abundance index. Annual trends in fishing are calculated as the year-effect derived from a general linear model (GLM) analysis of the index of fishing power. The fishing efficiency of Danish gill-netters and, to some extent, Danish seiners, has overall increased inside... |
Tipo: Text |
Palavras-chave: Fishing efficiency; Plaice box; Fisheries management; North Sea; Demersal fisheries. |
Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00589/70118/68112.pdf |
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Robinson, Craig D.; Webster, Lynda; Martinez-gomez, Concepcion; Burgeot, Thierry; Gubbins, Matthew J.; Thain, John E.; Vethaak, A. Dick; Mcintosh, Alistair D.; Hylland, Ketil. |
Understanding the status of contaminants in the marine environment is a requirement of European Union Directives and the Regional Seas Conventions, so that measures to reduce pollution can be identified and their efficacy assessed. The international ICON workshop (Hylland et al., in this issue) was developed in order to test an integrated approach to assessing both contaminant concentrations and their effects. This paper describes and assesses the concentrations of trace metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in sediments, mussels, and fish collected from estuarine, coastal and offshore waters from Iceland to the Mediterranean Sea. For organic contaminants, concentrations progressively increased from Iceland, to the... |
Tipo: Text |
Palavras-chave: Integrated assessment; ICES; North Atlantic; North Sea; Baltic Sea; Mediterranean Sea; Polycyclic aromatic hydrocarbons (PAHs); Polychlorinated biphenyls (PCBs); Trace metals; Environmental monitoring. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00324/43520/43051.pdf |
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Camphuysen, C.J.; Smeenk, C.; Addink, M.; Jansen, O.E.. |
Between 1998 and 2007, 2063 cetaceans were found stranded in the Netherlands, representing at least 14 species. Two species, humpback whale (Megaptera novaeangliae) and Blainville’s beaked whale (Mesoplodon densirostris), are additions to the Dutch list. Apart from the first humpback whales, relatively many balaenopterid whales were found in comparison with previous decades. Range extension of recovering populations may explain part of this trend. However, the decline in strandings frequency in sperm whales (Physeter macrocephalus), another species with a slowly recovering Atlantic population but with a distinct peak in strandings in the 1990s, suggests that the factors underlying these changes are complex. During the 20th century, the strandings frequency... |
Tipo: Article / Letter to the editor |
Palavras-chave: Cetaceans; Strandings; The Netherlands; North Sea; Wadden Sea; Fin whale; Sei whale; Minke whale; Humpback; 42.84. |
Ano: 2008 |
URL: http://www.repository.naturalis.nl/record/328649 |
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Lelievre, Stephanie; Vaz, Sandrine; Martin, C. S.; Loots, Christophe. |
The functional value of spawning habitats makes them critically important for the completion of fish life cycles and spawning grounds are now considered to be “essential habitats”. Inter-annual fluctuations in spawning ground distributions of dab (Limanda Limanda), plaice (Pleuronectes platessa), cod (Gadus morhua) and whiting (Merlangius merlangus) were investigated in the southern North Sea and eastern English Channel, from 2006 to 2009. The preferential spawning habitats of these species were modelled using generalised linear models, with egg distribution being used as proxy of spawners’ location. Egg spatial and temporal distributions were explored based on six environmental variables: sea surface temperature and salinity, chlorophyll a concentration,... |
Tipo: Text |
Palavras-chave: Egg Distribution; Spawning Grounds; North Sea; Temporal Variability; Habitat Modelling; GLM. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00185/29674/28046.pdf |
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Injuk, J.; Van Grieken, R.; De Leeuw, G.. |
The atmospheric input of up to 16 trace and other elements into the North Sea is further assessed from aerosol concentrations measured at a coastal station in Belgium, on ships during two cruises, and on a platform, in the years 1992-1994. The Slinn and Slinn model is used to calculate the dry deposition from the measured aerosol concentrations. The total (dry and wet) deposition into the North Sea environment is estimated to be (in tonnes per year): 560 for V, 1300 for Cr, 650 for Ni, 690 for Cu, 3500 for Zn and 1970 for Pb. The 'giant' particles dominate the fluxes. The atmospheric contribution to the total input into the North Sea, including riverine inputs and direct discharges, are estimated to be 28% for Cu, 29% for Zn and 57% for Pb. The inputs... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerosols Experimental data Fallout Heavy metals Measurement Modelling ANE; North Sea. |
Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=309 |
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Redant, F.; De Clerck, R.. |
The report describes the Belgian <i>Nephrops</i> directed fishery in the Central North Sea (Botney Gut-Silver Pit area) and analyzes the diurnal variations in CPUE and catch composition of several commercial <i>Nephrops</i> trawlers operating in this area. Peak CPUE-values were generally obtained after dawn and before dusk. Some anomalies however did occur. These are discussed in relation to the natural variations in light intensity on the sea floor and the food requirements of <i>Nephrops</i>. There was no evidence of significant changes in the length composition of <i>Nephros</i> taken at different times of the day. The data even suggest that all size groups of <i>Nephros</i> respond in the same... |
Tipo: Info:eu-repo/semantics/book |
Palavras-chave: Circadian rhythms Length Nephrops ANE; Belgium ANE; North Sea. |
Ano: 1984 |
URL: http://www.vliz.be/imisdocs/publications/129008.pdf |
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Fransz, H.G.; Mommaerts, J.-P.; Radach, G.. |
North Sea ecosystem models published in accessible literature are partitioned into groups with respect to their emphasis on significance and detail of different trophic levels of the ecosystem. These subsets are treated separately in the three main chapters, which deal with relationships with physical dynamics, lower trophic level interactions and higher trophic level interactions. They are preceded by chapters that introduce the scope of the models, the history of modelling approaches, main purposes and specific aims, general aspects of internal structure, and modelling techniques applied. The main chapters compare the process descriptions characteristic of the subsets of models, and discuss aims and results with emphasis on significance and contribution... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Benthos Ecosystem management Environmental effects Marine environment Models Nutrient cycles Plankton Predation Primary production Trophodynamic cycle ANE; North Sea. |
Ano: 1991 |
URL: http://www.vliz.be/imisdocs/publications/262355.pdf |
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Dedeurwaerder, H.L.; Dehairs, F.A.; Decadt, G.; Baeyens, W.F.J.. |
In this study we have investigated air-sea exchanges in the Belgian coastal area located in the Southern Bight of the North Sea. Since 1980 the tropospheric aerosol contents for the trace elements Cd, Cu, Mn, Pb, Zn and for the reference elements Al , Fe, Na have been monitored on an intermittent basis from a maritime sampling platform (Light-Vessel West-Hinder; position: 51°23.5'N- 2°21.5'E, fig. 1). During 1981 sampling campaigns at sea were paralleled by sampling campaigns on land, in the coastal area (natural reserve De Blankaert, located at 20 Km inland), in order to allow for a better evaluation of the specific source or sink role of the sea. No major source of pollution exists between the maritime and the continental sampling sites. During these... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aeolian deposits Resuspension Trace metals ANE; North Sea; Southern Bight. |
Ano: 1984 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3323 |
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Cotter, A; Mesnil, Benoit; Piet, G. |
A year-class curve is a plot of log cpue (catch per unit effort) over age for a single year class of a species (in contrast to the better known catch curve, fitted to multiple year classes at one time). When linear, the intercept and slope estimate the log cpue at age 0 and the average rate of total mortality, Z, respectively. Here, we suggest methodological refinements within a linear least squares framework. Candidate models may include a selectivity term, fleet-specific parameters, and polynomials in year to allow for gradual variations of Z. An iterative weighting method allows for differing precisions among the different fleets, and a forward (one-step ahead) validation procedure tests predicted cpue against observed values. Choice of the best... |
Tipo: Text |
Palavras-chave: Year class curve; Plaice; North Sea; Iteratively weighted least squares; Forward validation; Fish stock assessment; Cpue; Analysis of relative residual variance. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2776.pdf |
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Registros recuperados: 111 | |
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