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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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| 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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