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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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Allain, Virginie; Biseau, Alain; Kergoat, Bernard. |
French deepwater fish exploitation (500 m) began off the West coast of the British Isles in 1973. It further developed in the 1980s, and intensified in the 1990s. In 1997, the French fleet comprised 49 boats, and since 1995 has landed yearly about 19,500 t of deepwater fish species, of which, the grenadier Coryphaenoides rupestris (Macrouridae) has been the most abundant. Discard data were sampled on-board by observers on French high sea trawlers from 1995 to 1997. Eight species were identified as totally landed, 43 non-commercial species as totally discarded and only one, the grenadier, as both landed and discarded. The mean discarding rate by haul was 48.5% in weight, whereas the mean grenadier discarding rate was 21.2%; these rates increased with depth.... |
Tipo: Text |
Palavras-chave: Length frequency distribution; Discards; Discarding rate; Coryphaenoides rupestris; Alepacephalus bairdii. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-751.pdf |
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Pawlowski, Lionel; Lorance, Pascal. |
In the Northeast Atlantic fishery for roundnose grenadier Coryphaenoides rupestris, discards account for about 30% of the catch in weight. Data on discards are scarce; however, length distributions and discard rates appear to be relatively stable from year to year. In contrast, landings data available since 1990 show that the average pre-anal fin length has decreased from 20.7 cm in 1990 to 15.2 cm in 2008, resulting in a 58% reduction of the mean individual weight (850 g in 2008) and an increasing occurrence of overlapping class sizes between landings and discards in recent years. For stock assessment, the method of separable virtual population analysis (SVPA) was used. However, because of the lack of discard data for many of the years covered by the... |
Tipo: Text |
Palavras-chave: Stock assessment; Fishing effort; Discards; Time series; Macrouridae; Coryphaenoides rupestris; Atlantic Ocean. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11175/7527.pdf |
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