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dc.contributor.authorMcGarvey, Richard.en_US
dc.date.accessioned2014-10-21T12:35:42Z
dc.date.available2014-10-21T12:35:42Z
dc.date.issued1991en_US
dc.identifier.otherAAINN71424en_US
dc.identifier.urihttp://hdl.handle.net/10222/55249
dc.descriptionThe cyclical dynamics of the Georges Bank sea scallop fishery are investigated by time series and spatial data analysis, modelling, and dynamical hypothesis testing.en_US
dc.descriptionSurveys of Placopecten magellanicus, on Georges Bank, provided size-frequency distributions of the population from 1977 to 1988. Commercial time series of effort and catch, extending to 1944, corroborate the surveys. Population reproduction, early life history survival, and stock-recruitment interactions, within and between subareas along the clockwise direction of current flow, are computed.en_US
dc.descriptionRecruitment and egg production on the Northern Edge and Northeast Peak are correlated, suggesting a reproductively self-sustaining population. Large increases in stock-recruitment correlations were observed when the egg contribution of newly fecund scallops ages 3 and 4 was omitted from yearly totals which, together with physiological studies, suggests that scallops age 3 and 4 are not yet fully mature. Recruitment could be substantially enhanced by raising age of first capture.en_US
dc.descriptionHypotheses for the 15-year cycle of Georges Bank scallops are threefold; periodic environmental forcing, Schaefer predator-prey, or Ricker density dependence. The fishery closely matches assumptions and mathematical features of the age-structured, stochastic-recruitment Schaefer model, comparing auto- and cross-correlations of recruitment, effort and stocksize from model and data. Population cycle hypothesis testing criteria are applied that are qualitative, and therefore robust.en_US
dc.descriptionDensity dependence is implicated from age structure before compared with under exploitation. Due to a greatly shortened lifespan in the fishery, egg survivorship to age 2 is 300 times greater, estimated from survey, compared with a natural population, whose egg to recruit survival is deduced as the reciprocal of mean lifetime egg production.en_US
dc.descriptionThesis (Ph.D.)--Dalhousie University (Canada), 1991.en_US
dc.languageengen_US
dc.publisherDalhousie Universityen_US
dc.publisheren_US
dc.subjectBiology, Ecology.en_US
dc.subjectBiology, Oceanography.en_US
dc.subjectAgriculture, Fisheries and Aquaculture.en_US
dc.titleDynamics of the Georges Bank scallop fishery.en_US
dc.typetexten_US
dc.contributor.degreePh.D.en_US
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