Local dispersion of nonmotile invasive bivalve species by wind-driven lake currents

Abstract

Asian clam (Corbicula fluminea) is among the most aggressive freshwater invaders worldwide causing major ecological and economic damage. However, the mechanisms leading to the water-borne dispersion of the species within aquatic ecosystems, particularly lakes, is an area where research is at a relatively early stage. A numerical model has been developed to analyze and describe the dispersion that is produced by the actions of waves and currents. The model represents the basic particle processes of release (R), water-borne transport (T), and survival (S). The model has been applied to a large, deep lake—Lake Tahoe. The dispersion model results reveal that (1) under episodic, extreme wind forcing, larvae are carried away from the original areas, along a discrete number of preferred pathways, (2) bays can act as retention zones, with low current velocities and recirculating eddies, and (3) the majority of the larvae released in the infested areas stay within these areas or disperse on a small spatial scale.