|
|
|
| Registros recuperados: 173 | |
|
|
| 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 |
| |
|
| |
|
|
| Fromentin, Jean-marc; Restrepo, Victor. |
| At the ICCAT symposium on bluefin tuna that held in Santander in April 2008, Tangen et al.(2009) presented a first quantification of the fishing effort deployed by the Norwegian fishery targeting bluefin tuna in the North Sea and Norwegian Sea. Using a year-class curve analysis on the Norwegian CPUE, this document presents the first estimates of mortality rates of Atlantic bluefin tuna that migrated north from the mid-1950s to the late 1970s. The results indicate that bluefin tuna would have experienced a total mortality rate (Z) of 0.2 to 0.4 yr-1 (i.e. F at around 0.3 yr-1) during the late 1950s, 0.2 yr-1 during the 1960s and 0.1 yr-1 afterwards (assuming M=0.1 yr-1). These results appear to be rather robust and consistent with the VPA estimates from the... |
| Tipo: Text |
Palavras-chave: Thunnus thynnus; Fishing and natural mortalities; Year-class curves; Stock assessment. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00192/30294/28783.pdf |
| |
|
| |
|
|
| Hattour, A.; Ben Abdallah, L.; Guennegan, Y.. |
| Within the frame of the National Program (PNM), 'Assessment of Marine Tunisian Resources' (1996-1999), two prospecting surveys on small pelagic fishes, have been led in narrow collaboration with French Institute IFREMER. Their objectives were to specify the relative fishes abundance, their spatial-temporal variability but also to quantify the maximum sustainable yield (MSY) of this resource. A third important goal was to familiarize a Tunisian scientist team, with numerical methods and data processing used during the cruises (reading of echograms, treatments of data, etc.) in stocks assessment. It is known that the indirect stocks assessment methods of small pelagic species is not reliable, reason for which we opted to apply echo - integration techniques.... |
| Tipo: Journal Contribution |
Palavras-chave: Abundance; Biomass; Fishery surveys; Pelagic fisheries; Potential yield; Stock assessment; Biomass; Stock assessment; Pelagic fisheries; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_24251; Http://aims.fao.org/aos/agrovoc/c_5659. |
| Ano: 2004 |
URL: http://hdl.handle.net/1834/4237 |
| |
|
|
| Archarnbault, Benoit; Le Pape, Olivier; Baulier, Loic; Vermard, Youen; Veron, Matthieu; Rivot, Etienne. |
| We explore how alternative hypotheses on the degree of mixing among local subpopulations affect statistical inferences on the dynamics and stock assessment of a harvested flatfish population, namely, the common sole population in the Eastern Channel (ICES area VIId). The current paradigm considers a single, well-mixed, spatially homogeneous population with juveniles from all coastal nursery grounds along the French and UK coasts that contribute to a single adult population and one pool of eggs. Based on the available data and ecological knowledge, we developed a spatial Bayesian integrated life-cycle model that consists of three subpopulations (one near the UK coast and two near the French coast, denoted UK, West FR and East FR, respectively) supported by... |
| Tipo: Text |
Palavras-chave: Solea solea; Spatial life-cycle model; Coastal nurseries; Connectivity; Stock assessment; Hierarchical bayesian model. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00333/44430/44231.pdf |
| |
|
| |
|
|
| Inacio, A.; Barros, P.C.. |
| Foi feita uma avaliação da pescaria e do manancial de Hilsa kelee (magumba) na Baía de Maputo em Janeiro de 2011. Para a avaliação, foram aplicados dois tipos de modelos, um modelo dinâmico de produção geral baseado no modelo logístico de Schaefer, usando os dados de captura e índices de abundância, modelos baseados na composição por comprimentos e um modelo de podução por recruta por comprimentos com uma série de dados do período de 1992-2010. Os níveis de esforço de pesca mais elevados foram registados no ano de 2007 e o menor em 2009. As capturas totais estimadas para o período de 2006 a 2010 apresentam níveis abaixo das 3.000 t. O valor estimado mais baixo, cerca de 1.100 t, foi para o ano de 2009. A CPUE mostra um nível baixo em 2007 (119 kg por dia... |
| Tipo: Journal Contribution |
Palavras-chave: Fish stocks; Stock assessment. |
| Ano: 2012 |
URL: http://hdl.handle.net/1834/5141 |
| |
|
|
| Wöhler, O.C.; Giussi, A.R.; Hansen, J.E.. |
| Sequential population analysis on Long Tail Hake (Macruronus magellanicus)from the Southwest Atlantic. Years 1985-1995. VPA on the Long Tail Hake (Macruronus magellanicus), based on data covering the years 1985 up to 1995, was performed to assess the current state of the stock. Simulation trials, inducing uncertainty about both the natural mortality rate and recruitment were also accomplished, to evaluate the risk of overfishing which is associated to different fishing alternatives, always under the assumption of a single and closed Long Tail Hake population. CPUE data were not appropriate for tunning, so the traditional VPA has been applied. During the period of study, stock biomass and spawning stock biomass showed an increased trend. Long and short-term... |
| Tipo: Journal Contribution |
Palavras-chave: Stock assessment; Fishery management; Catch/effort; Fishing mortality; Overfishing; Biomass; Sexual maturity; Stock assessment; Fishery management; Biomass; Overfishing; Sexual maturity; Http://aims.fao.org/aos/agrovoc/c_24251; Http://aims.fao.org/aos/agrovoc/c_24026; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_34068; Http://aims.fao.org/aos/agrovoc/c_7016. |
| Ano: 1999 |
URL: http://hdl.handle.net/1834/1875 |
| |
|
| |
|
| |
|
|
| Nishida, T.; Komatsu, T.. |
| Strengthening tuna management is one of the primary tasks for the new Indian Ocean Tuna Commission (IOTC). Stock assessment and the prediction of the dynamics of the tuna resources will become increasingly important research topics because they provide the basic information for the management decision process. Under these circumstances, this paper attempts to develop the stock analyses and prediction techniques using neural networks. As a first step and as a test study, analyses and predictions of catch rates of the Japanese yellowfin tuna longline fisheries are attempted. |
| Tipo: Proceedings Paper |
Palavras-chave: Fishery management; Stock assessment; Catch/effort; Tuna fisheries. |
| Ano: 1998 |
URL: http://hdl.handle.net/1834/60 |
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
|
| Rey-valette, H; Martins, P. |
| A new programme concerning the experimentation of about thirty Fish Aggregating Devices (FADs) is to start in the Cape Verde Islands at the end of 1999. In this context, this communication is intended: - to evaluate the halieutic, economic and social conditions of the artisanal fishery in this archipelago, notably in terms of assets and constraints. Although these conditions are very heterogeneous depending on islands, the fads seem to be able to help the stabilization and the development of the fishing activities, disadvantaged by a low productivity, limited operating ranges of boats, and very irregular outings at sea. But the narrowness of the domestic market is likely to cause drops in the fish prices if the production increases, while the absence of... |
| Tipo: Text |
Palavras-chave: Attracting techniques; Capture fishery economics; Fishery management; Operational costs; Stock assessment; Tuna fisheries; Article Geographic Terms: Cape Verde Is.. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00042/15317/12644.pdf |
| |
|
|
| Caill-milly, Nathalie; Duclercq, Benoit; Morandeau, Gilles. |
| Between 1980 and 1986, some Arcachon oyster farmers took up breeding the Japanese clam on the foreshore (Robert et Deltreil, 1990). This production was short lived. The steep fall in prices due to economic competition from Spain, Portugal, Italy and Tunisia, predator action such as the trigger fish (Popovsky et al., 1999), added to the significant amount of mortality that occurred in the summer and autumn of 1992 that affected two-thirds of the total stock, led to clam farming being abandoned at the end of the 1980s. In the Arcachon basin, the Japanese clam (Ruditapes philippinarum) population, now natural to the area, has found favourable conditions for development and is expanding rapidly there. This species has been supplanting the local species... |
| Tipo: Text |
Palavras-chave: Ruditapes philippinarum; Veneridae; Popluation structure; Biomass; Stock assessment; Arcachon Bassin; Veneridae; Ruditapes Philippinarum; Bivalvia; Mollusca; Structure Population; Biomasse; Abondance; Evaluation Stock. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/2006/rapport-2218.pdf |
| |
| Registros recuperados: 173 | |
|
|
|
