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Alemany, Juliette; Rivot, Etienne; Foucher, Eric; Vigneau, Joel; Robin, Jean-paul. |
Among the English Channel fishery, the importance of cuttlefish stock has increased, following the cephalopods global landings and market trend. An adapted stock assessment model is needed in order to give good management advice with accurate uncertainties. Age based methods in this species are hampered by time consuming age determination with statoliths. A model requiring few data and adapted to the species life-history is therefore proposed. An assessment of this stock was conducted in June 2015 by fitting a two-stage biomass model on a 22 years’ time-series (1992-2014). The use of a Bayesian framework is particularly adapted for decision making, allowing the propagation of uncertainty in the model. It also permits the use of different sources of... |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00379/49066/49514.pdf |
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Alemany, Juliette; Foucher, Eric; Rivot, Etienne; Vigneau, Joel; Robin, Jean-paul. |
Among the English Channel fishery, the importance of cuttlefish stock has increased, following the cephalopods global landings and market trend. The stock is currently managed at regional scale but not by European regulations, although it is a shared species targeted by French and British fishing fleets at several stages of its life-cycle and across much of its distributional range. An assessment of this stock was conducted in June 2014 by fitting a two-stage biomass model on a 22 years’ time-series (1992-2013). As the assumptions of the model are based on a simplified life-cycle, it would be appropriate to compare the results with outputs from other models in order to obtain reliable biomass estimations. The final aim is to produce reliable management... |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00377/48773/49171.pdf |
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Gras, Michael; Roel, Beatriz A.; Coppin, Franck; Foucher, Eric; Robin, Jean-paul. |
The English Channel cuttlefish (Sepia officinalis) is the most abundant cephalopod resource in the Northeast Atlantic and one of the three most valuable resources for English Channel fishers. Depletion methods and age-structured models have been used to assess the stock, though they have shown limitations related to the model assumptions and data demand. A two-stage biomass model is, therefore, proposed here using, as input data, four abundance indices derived from survey and commercial trawl data collected by Ifremer and Cefas. The model suggests great interannual variability in abundance during the 17 years of the period considered and a decreasing trend in recent years. Model results suggest that recruitment strength is independent of spawning-stock... |
Tipo: Text |
Palavras-chave: Abundance indices; English Channel; Exploitation rate; Sepia officinalis; SST; Stock–recruitment relationship; Trawl survey; Two-stage biomass model. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00248/35923/34448.pdf |
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Guerault, Daniel; Desaunay, Yves; Bellois, Pierre; Grellier, Patrick; Robin, Jean-paul; Robineau, Brigitte. |
A survey of the glass-eel fishery in the Loire estuary in 1987 (265 boats, 117 tons gasseel, 13733 fishing trips) showed that 16 fishery species constitute the by-catch (49,3 million individuals, mainly juveniles, among which 98 % consist in flounder, sprat and brown shrimp). The analysis of catches in space and time leads to proposaIs for Iimiting the impact during the last fishing weeks. Taking into account the naturai mortality rates of the concerned juveniles, an attempt is made to estimate the actuai impact of the glasseel fishery, after a delay. Only 10 % of the caught brown shrimps wouid have been recruited in the summer shrimp fishery. Up to 85,5 to 97,6 % of juvenile fishes would have disappeared during the following year by natural mortality. |
Tipo: Text |
Palavras-chave: Anguille; Pêcherie; Prises accessoires; Estuaire; Loire; Eel; Fishery; By catch; Estuary; Loire. |
Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/00120/23102/20951.pdf |
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Faillettaz, Robin; Roger, Christophe; Mathieu, Michel; Robin, Jean-paul; Costil, Katherine. |
The presence of shells of the Atlantic rangia, Rangia cuneata, a brackish-water species native from the Gulf of Mexico also known as gulf wedge clam, was reported in 2017 on the French coasts of the English Channel, in the waterway that connects Caen to the sea. However, no information was available on whether a population of this alien species had successfully established in the region. Here, only empty shells—except for one live individual—were sampled in that waterway, and the sampling was shifted to the nearby marina of Ouistreham, where water is mesohaline (6.89 ± SD 0.06 PSU). In spring 2017, the mean density in the marina reached 110.45 ± 86.08 ind m-2, largely dominating the benthos community. The population was mostly composed of fairly large... |
Tipo: Text |
Palavras-chave: The Atlantic rangia; Alien species; Normandy (F); Brackish waters; Density; Growth; Reproduction. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00634/74623/74515.pdf |
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