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Holley, Jean-francois; Marchal, Paul. |
A typology is presented for the French offshore fleet fishing in the North Atlantic. The investigation was carried out separately for all years between 1985 and 2002. Two methods were combined: PCA and cluster analysis. In 1985, most vessels targeted saithe off western Scotland (vessels from Lorient) and in the northern North Sea (vessels from Boulogne and Fecamp). Then, probably because of the decline in biomass of saithe, some vessels started to target deepwater species from the early 1990s. In 2002, some vessels fished exclusively for saithe (>80%), while others targeted mainly deepwater species. In all, 12 fisheries are identified for the period 1985-2002. Results are given of a preliminary investigation trying to identify the external factors... |
Tipo: Text |
Palavras-chave: Saithe; Multivariate analyses; Mixed fisheries; Fishing strategy; Fisheries dynamics; Deepwater species. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-384.pdf |
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Lorance, Pascal; Pawlowski, Lionel; Trenkel, Verena. |
A database of tallybooks, from skippers' own logbooks, provided by the French industry involved in deep-water fishing to the west of the British Isles was used to standardise blue ling Landings per Unit of Effort (LPUEs). The data covered the years 1992-2008 with more extensive data for the period 2000-2007. For each haul, landings by species, tow duration, depth and location were reported. Compared to EU logbooks, this database is on a haul by haul basis instead of being aggregated by fishing sub-trips combining hauls from the same day, ICES rectangle and gear. Moreover, it includes depth, which is a major factor for catch rates in deepwater fisheries. LPUEs were estimated from Generalised Additive Models (GAMs) with depth, vessel, statistical rectangle... |
Tipo: Text |
Palavras-chave: Molva dypterygia; Abundance indices; Fishing strategy; Tweedie distribution. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00102/21330/18953.pdf |
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Trenkel, Verena; Rochet, Marie-joelle; Mahevas, Stephanie. |
Norway lobster, Nephrops norvegicus (L.) was found to show diel activity patterns with more individuals outside their burrows at dawn and dusk in the Bay of Biscay in August 2004 and catchabilities were higher at these times. Using data from an onboard observer programme of Nephrops trawlers in 2002-2005, we investigated whether the expected variability in catchability was visible in commercial catches. Catch numbers per haul varied spatially and between months but no signal for diel variations was found. Fishing strategies developed by the Nephrops trawlers had several components. On a seasonal level they started around sunrise. On a haul level, haul duration decreased from haul to haul, with the longest hauls taking place at the time of highest... |
Tipo: Text |
Palavras-chave: Time of day; Fishing strategy; Diel activity patterns; Catchability. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2618.pdf |
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Gourguet, Sophie; Thebaud, Olivier; Dichmont, C.; Jennings, S.; Little, L. R.; Pascoe, S.; Deng, R. A.; Doyen, L.. |
Balancing bio-economic risks and high profit expectations is often a major concern in fisheries management. We examine this trade-off in the context of the Australian Northern Prawn Fishery (NPF). The fishery derives its revenue from different prawn species with different dynamics and recruitment processes. A multi-species bio-economic and stochastic model is used to examine the trade-offs between mean profitability of the fishery and its variance, under a range of economic scenarios, fishing capacities and distributions of fishing effort across the various sub-fisheries that comprise the NPF. Simulation results show that the current fishing strategy diversifying catch across sub-components of the fishery entails a compromise between expected performance... |
Tipo: Text |
Palavras-chave: Bio-economic modelling; Uncertainty; Risk-performance trade-offs; Fishing strategy; Northern Prawn Fishery. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00216/32775/31320.pdf |
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Lorance, Pascal; Pawlowski, Lionel; Trenkel, Verena. |
Haul-by-haul data derived from skippers' personal logbooks, from the French deep-water fishery to the west of the British Isles, were used to calculate standardized blue ling (Molva dypterygia) landings per unit effort (lpue) for the period 2000-2008. Lpue values were estimated using generalized additive models with depth, vessel, statistical rectangle, area, and year as explanatory variables. Because of their statistical distribution, landings were modelled by a Tweedie distribution, which allows datasets to contain many zeros. To investigate how to track stock trends reliably, lpue values were estimated in five areas for different subsets of the data. The subsets consisted of hauls during the spawning season (when blue ling aggregate), outside the... |
Tipo: Text |
Palavras-chave: Abundance indices; Fishing strategy; GAM; Molva dypterygia; Tallybook. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00016/12713/9647.pdf |
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