The Biological and Demographic Factors Determining Popultion Connectivity in Sea Scallops (Placopecten magellanicus) on Georges Bank

Abstract

The Georges Bank (GB) scallop (Placopecten magellanicus) population is an economically valuable fishery in Canada and the US. The roles of biological factors such as larval swimming behaviour, development rates and spawning season and of demographic factors such as adult distribution and larval mortality in determining population connectivity in scallops on GB are currently unknown. In this thesis, a new particle-tracking model is developed and used to simulate larval dispersal in realistic 3D currents. It highlights the influences of biological and demographic factors, and quantifies their effects on larval dispersal and population connectivity. Larval depth-distribution and adult distribution are found to have significant impacts, and further, it is suggested that the previously overlooked spring spawning event may contribute significantly to population connectivity. These results are used to help prioritize future field, lab and modelling work that is requisite to understanding the connectivity in this metapopulation.