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| Registros recuperados: 75 | |
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| Marandel, Florianne; Lorance, Pascal; Trenkel, Verena M.. |
| The thornback ray (Raja clavata) in the Bay of Biscay is presumed to have declined during the 20th Century. To evaluate this decline and estimate biomass trajectories, a hypothetical catch time series was created for the period 1903-2013. A Bayesian state-space biomass production model with a Schaefer production function was fitted to the hypothetical catch time series and to a shorter research vessel Catch Per Unit Eeffort (CPUE) time series (1973-2013, with missing years). A censored likelihood made it possible to obtain biomass estimates without a CPUE time series or only with an estimate of biomass depletion. A simulation-estimation approach showed a high sensitivity of results to the prior for the intrinsic growth rate. The model provided biomass... |
| Tipo: Text |
Palavras-chave: Population dynamics; Stock assessment; Data poor; Censored data; Bayes; Thornback ray; State-space model. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00359/47032/46947.pdf |
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| Trenkel, Verena; Bravington, Mark V.; Lorance, Pascal. |
| Catch curves are widely used to estimate total mortality for exploited marine populations. The usual population dynamics model assumes constant recruitment across years and constant total mortality. We extend this to include annual recruitment and annual total mortality. Recruitment is treated as an uncorrelated random effect, while total mortality is modelled by a random walk. Data requirements are minimal as only proportions-at-age and total catches are needed. We obtain the effective sample size for aggregated proportion-at-age data based on fitting Dirichlet-multinomial distributions to the raw sampling data. Parameter estimation is carried out by approximate likelihood. We use simulations to study parameter estimability and estimation bias of four... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00130/24168/22506.pdf |
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| Allain, Valerie; Lorance, Pascal. |
| Age is a necessary parameter used in population dynamics to assess the state of exploited resources. This parameter is poorly known for most deep-sea species (depth > 400 m). This work focused on age estimation from otoliths of Alepocephalus bairdii (Alepocephalidae), Coryphaenoides rupestris (Macrouridae), Helicolenus dactylopterus (Sebastidae) and Hoplostethus atlanticus (Trachichthyidae), which French fishery exploitation, off the west coasts of the British Isles, began the late 1980's. Considering otolith growth zones as annual, the four species all show high longevity: 38, 54, 43 and 130 years, respectively, together with slow growth. The differences in growth between sex were estimated and difficulties in accurately estimating the age were... |
| Tipo: Text |
Palavras-chave: Alepocephalus bairdii; Coryphaenoides rupestris; Helicolenus dactylopterus; Hoplostethus atlanticus; ANE; Slope fish; Age estimation; Otoliths. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00000/10396/7690.pdf |
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| Dransfeld, Leonie; Gerritsen, Hans D.; Hareide, Nils R.; Lorance, Pascal. |
| 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... |
| Tipo: Text |
Palavras-chave: Ecological risk assessment; VMS; Continental slope; Beryciformes; Atlantic Ocean. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00176/28758/27234.pdf |
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| Uiblein, F; Lorance, Pascal; Latrouite, Daniel. |
| Much is known in very broad terms about the distribution of deep-sea fishes, but information on fine-scale habitat selection and behaviour in the largest living space on earth is still rare. Based on video sequences from 4 dives performed with the manned submersible 'Nautile' at depths between 400 and 2000 in in the Bay of Biscay, NE Atlantic, we studied the behaviour of co-occurring slope-dwelling deep-sea fishes. Five different habitats were identified according to depth range or topographical and hydrological characteristics. For each fish species or genus that could be identified, estimates of absolute abundance were provided. The most frequently occurring species, round-nose grenadier Coryphaenoides rupestris, blackmouth catshark Galeus melastomus,... |
| Tipo: Text |
Palavras-chave: Submersible observations; Assemblage structure; Density; Locomotion; Vertical positioning; Foraging; Species specific; Behavioural flexibility. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00000/10666/7591.pdf |
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| Farias, Ines; Morales-nin, Beatriz; Lorance, Pascal; Figueiredo, Ivone. |
| The biology, ecology, and dynamics of the deep-sea teleost black scabbardfish in the northeast Atlantic are reviewed. The black scabbardfish is a commercial bathypelagic species found in the NE Atlantic mostly from Iceland to the Canary Islands and Western Sahara, at depths from 800 to 1300 m. The spatial structure of its population is still uncertain, although the existence of one single stock that migrates around the NE Atlantic driven by feeding and reproduction is the most likely hypothesis consistent with available data. This review is based on data from commercial fisheries off the Faroe Islands, Hatton Bank, the west of the British Isles, and Portugal (mainland, Azores, and Madeira) and from Icelandic and Scottish scientific surveys collected... |
| Tipo: Text |
Palavras-chave: Deep-water longline fisheries; Migration; Life cycle; Trichiuridae; Aphanopus carbo; North Atlantic Ocean. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00175/28636/27058.pdf |
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| Fernandes, Paul G.; Ralph, Gina M.; Nieto, Ana; Criado, Mariana Garcia; Vasilakopoulos, Paraskevas; Maravelias, Christos D.; Cook, Robin M.; Pollom, Riley A.; Kovacic, Marcelo; Pollard, David; Farrell, Edward D.; Florin, Ann-britt; Polidoro, Beth A.; Lawson, Julia M.; Lorance, Pascal; Uiblein, Franz; Craig, Matthew; Allen, David J.; Fowler, Sarah L.; Walls, Rachel H. L.; Comeros-raynal, Mia T.; Harvey, Michael S.; Dureuil, Manuel; Biscoito, Manuel; Pollock, Caroline; Phillips, Sophy R. Mccully; Ellis, Jim R.; Papaconstantinou, Constantinos; Soldo, Alen; Keskin, Cetin; Knudsen, Steen Wilhelm; Gil De Sola, Luis; Serena, Fabrizio; Collette, Bruce B.; Nedreaas, Kjell; Stump, Emilie; Russell, Barry C.; Garcia, Silvia; Afonso, Pedro; Jung, Armelle B. J.; Alvarez, Helena; Delgado, Joao; Dulvy, Nicholas K.; Carpenter, Kent E.. |
| Europe has a long tradition of exploiting marine fishes and is promoting marine economic activity through its Blue Growth strategy. This increase in anthropogenic pressure, along with climate change, threatens the biodiversity of fishes and food security. Here, we examine the conservation status of 1,020 species of European marine fishes and identify factors that contribute to their extinction risk. Large fish species (greater than 1.5 m total length) are most at risk; half of these are threatened with extinction, predominantly sharks, rays and sturgeons. This analysis was based on the latest International Union for Conservation of Nature (IUCN) European regional Red List of marine fishes, which was coherent with assessments of the status of fish stocks... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00416/52739/53608.pdf |
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| Nicolaus, E. E. Manuel; Barry, Jon; Bolam, Thi P. C.; Lorance, Pascal; Marandel, Florianne; Phillips, Sophy R. Mccully; Neville, Suzanna; Ellis, Jim R.. |
| Trace metal concentrations in muscle and liver tissues from two offshore species of skate were examined. Concentrations of mercury in muscle of Leucoraja circularis (n = 20; 23–110.5 cm total length, 157–490 m water depth) and L. fullonica (n = 24; 28.5–100 cm total length, 130–426 m water depth) were 0.02–1.8 and 0.04–0.61 mg kg− 1, respectively. Concentrations of both As and Hg increased with total length. Only the largest specimen had a concentration of Hg in muscle > 1.0 mg kg− 1. Data were limited for specimens > 90 cm long, and further studies on contaminants in larger-bodied skates could usefully be undertaken. |
| Tipo: Text |
Palavras-chave: Trace metals; Sandy ray; Shagreen ray; Bay of Biscay; Celtic Sea. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00397/50829/51592.pdf |
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| Registros recuperados: 75 | |
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