Original paper

Zebra mussel (Dreissena polymorpha) veliger larvae: distribution and relationship to phytoplankton biomass and composition in the Rideau River, Ontario, Canada

Vidal, Maeva; Hamilton, Paul B.; Pick, Frances R.

Abstract

The zebra mussel (Dreissena polymorpha) is an invasive species in the Rideau River (Ontario, Canada), where it was first discovered in the early 1990s. The spatial and temporal distributions of its larvae were examined in relation to phytoplankton community structure and chlorophyll-a concentrations in this lowland river. Two peaks in larval density were anticipated over the ice-free season. However, D. polymorpha in the Rideau River waterbasin had only one major spawning event in late May or early June, and seed populations were concentrated in the lower reaches. No clear association between water chemistry and veliger densities was observed, although a significant negative correlation was found between chlorophyll-a concentrations and veliger densities when a spatial lag was incorporated into the analysis pointing to a downstream impact of adult zebra mussel beds on phytoplankton biomass. However, no significant impact on phytoplankton taxonomic composition or size distribution was detected.

Keywords

dreissena polymorphaveligerschlorophyllphytoplanktonrideau river