GEOSCAN, résultats de la recherche


TitreThe impact of commercial fishing on the determination of habitat associations of sea scallops
AuteurSmith, S J; Black, J; Todd, B J; Kostylev, V E
SourceICES Annual Science Conference, abstracts; 2009 p. 140-141
Séries alt.Secteur des sciences de la Terre, Contribution externe 20080216
Réunion2008 ICES Annual Science Conference; Halifax; CA; Septembre 22-26, 2008
ProvinceRégion extracotière de l'est
Lat/Long OENS-66.4167 -65.5000 43.6667 43.1667
Sujetspeuplements biologiques; biomes; diversification biotique; écosystèmes; écologie marine; bathymétrie; topographie du fond océanique; topographie du fond océanique; assemblages fauniques; distribution de la faune; etudes fauniques; faunes; géologie marine; géologie de l'environnement
ProgrammeLes géosciences à l'appui de la gestion des océans
Résumé(disponible en anglais seulement)
The sea scallop (Placopecten magellanicus) population off southwestern Nova Scotia in Scallop Fishing Area 29 has been monitored by an annual drag survey since the fishery started there in 2001. A new stratification scheme based upon surficial geology maps from a multibeam bottom mapping and geology groundtruth project completed in 2004 in this area have been used for the survey design since 2005. Survey data from before 2005 have been post-stratified using the new strata. The efficiency of the design with respect to variance reduction appears to have diminished over time suggesting that the association between scallop abundance and bottom type may not have been as strong or constant as first assumed. Modelling of the association between scallop abundance and bottom type and depth using a Bayesian hierarchical approach confirms this diminishing relationship. Comparison of the results from the model with spatial measures of fishing effort based upon satellite vessel monitoring data suggests that either the habitat is being changed by fishing or the use of abundance as an indicator of the strength of preference or association is misleading when the population is being depleted by the fishery. We were able to track these changes because we had survey data from the beginning of this fishery. These results could have implications on the interpretation of species habitat associations from areas where data is only available from periods when the population had been exploited over a long time.