| dc.contributor.author | McGarvey, Richard. | en_US |
| dc.date.accessioned | 2014-10-21T12:35:42Z | |
| dc.date.available | 1991 | |
| dc.date.issued | 1991 | en_US |
| dc.identifier.other | AAINN71424 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55249 | |
| dc.description | The 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.description | Surveys 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.description | Recruitment 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.description | Hypotheses 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.description | Density 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.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1991. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biology, Ecology. | en_US |
| dc.subject | Biology, Oceanography. | en_US |
| dc.subject | Agriculture, Fisheries and Aquaculture. | en_US |
| dc.title | Dynamics of the Georges Bank scallop fishery. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
