Éditeur(s) : Elsevier
Résumé : This paper presents a survey of French Eastern English Channel fishers' observations of the past and current state of the marine ecosystem and their wishes for the future, as a first step towards formulating management objectives. Twenty-nine semi-directive interviews were carried out in June 2006 among fishers and shellfish farmers. Cognitive maps proved useful to formalise their experience and knowledge. Most interviewees mentioned a decrease of the resource in recent years and pointed out the presence of several problems, such as pollution, degradation of the ocean floor and harmful impacts of human activities, including fishing. The indicators used by the fishers as the basis to form their opinion were similar to those generally used by scientists for assessing the state of exploited marine populations and communities (average fish length, CPUE, fished biomass...); additional indicators were the timing and duration of fishing seasons. (c) 2008 Elsevier Ltd. All rights reserved.
Ocean & Coastal Management (0964-5691) (Elsevier), 2008-06 , Vol. 51 , N. 6 , P. 450-462

Droits : 2008 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/2008/publication-6134.pdf
DOI:10.1016/j.ocecoaman.2008.04.005
http://archimer.ifremer.fr/doc/00000/6134/

Éditeur(s) : Elsevier
Résumé : Choice of sampling method and survey period can have an important impact on the perception of the structure and dynamics of an ecological community. For the Celtic Sea fish assemblage we compared data obtained by three different trawl surveys: an autumn groundfish survey with a GOV trawl, and a spring and an autumn groundfish survey, both carried out with a Portuguese high-headline trawl. Time-series of abundance estimates were not consistent among surveys for all species and were generally very noisy. An analysis of variance components showed that the sampling method contributed more to the variance in abundance estimates compared to survey period, interannual variability, or even sampling variance. Overall community assessments based on indicators such as proportions of non-commercial and piscivorous species, and the proportion of benthic species showed similar trends for all data series. The shape of the size spectrum based on abundances per length class summed over all fish species, although stable over time, was highly sensitive to the sampling method. With the exception of size spectra, community indicators for marine fish assemblages monitored by surveys seem to be robust to survey period and trawling gear, but species abundance trends are method dependent.
ICES Journal of Marine Science (1054-3139) (Elsevier), 2004-05 , Vol. 61 , N. 3 , P. 351-362

Droits : 2004 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd
http://archimer.ifremer.fr/doc/2004/publication-899.pdf
DOI:10.1016/j.icesjms.2004.01.004
http://archimer.ifremer.fr/doc/00000/899/

Éditeur(s) : Oxford university press
Résumé : The results of a survey on fishers' perceptions of recent changes in the eastern English Channel ecosystem carried out in 2006 were compared with fishery and bottom-trawl survey data. A hypothesis-testing framework was used, testing the null hypothesis that fishers' statements were true, which permitted evaluation of both agreement and disagreement. Overall good agreement between fishers' statements and scientific data was found, and both sources suggested that the fish community in the Channel is undergoing large changes, among which are decreases in some commercially important species; in addition, a number of human pressures impact the ecosystem. Fishers had an accurate perception of changes and their time-frames, but not necessarily of their causes. They had a greater power than survey data to detect recent changes, showing that fishers' perceptions have great potential as early warning signals.
ICES Journal of Marine Science (1054-3139) (Oxford university press), 2008-09 , Vol. 65 , N. 6 , P. 1057-1068

Droits : 2008 International Council for the Exploration of the Sea. Published by Oxford Journals.
http://archimer.ifremer.fr/doc/2008/publication-4474.pdf
DOI:10.1093/icesjms/fsn062
http://archimer.ifremer.fr/doc/00000/4474/

Éditeur(s) : Wiley-blackwell
Résumé : An ecomorphological method was developed, with a focus on predation functions, to define functional groups in the Celtic Sea fish community. Eleven functional traits, measured for 930 individuals from 33 species, led to 11 functional groups. Membership of functional groups was linked to body size and taxonomy. For seven species, there were ontogenetic changes in group membership. When diet composition, expressed as the proportions of different prey types recorded in stomachs, was compared among functional groups, morphology-based predictions accounted for 28-56% of the interindividual variance in prey type. This was larger than the 12-24% of variance that could be explained solely on the basis of body size. (C) 2013 The Fisheries Society of the British Isles
Journal Of Fish Biology (0022-1112) (Wiley-blackwell), 2013-08 , Vol. 83 , N. 2 , P. 355-377

Droits : 2013 The Fisheries Society of the British Isles
http://archimer.ifremer.fr/doc/00152/26294/24831.pdf
DOI:10.1111/jfb.12177
http://archimer.ifremer.fr/doc/00152/26294/