Using 2-dimensional dispersal kernels to identify the dominant influences on larval dispersal on continental shelves

Abstract

Pelagic larval dispersal is thought to be the main mechanism connecting many marine populations and is an important determinant both of an individual's success and a population's distri- bution and spatial structure. Thus, quantitative estimates of the retention or dispersion of larvae from spawning grounds is important for the determination of recruitment success in fisheries. Models can be used to study connectivity through a dispersal curve or dispersal kernel: the probability that a larva will settle at a given distance from its release location. We applied a 3-dimensional circulation model and a Lagrangian particle tracking model to the southeast US continental shelf to describe dispersal kernels in 2 dimensions. We used a fully orthogonal design to assess the importance of fac- tors that influence the dispersal kernel, including spawning time, spawning location, larval behavior (vertical position in the water column), larval duration, and turbulent dispersal. Our results indicate that adult behavior, in the form of spawning time and location, may be more important than larval behavior in determining larval dispersal on the inner- and mid-shelves in this region.