Estimating the dispersal capacity of the introduced green mussel, Perna viridis (Linnaeus, 1758), from field collections and oceanographic modeling

Introduced species can often cause negative environmental and economic effects, but also offer opportunities to study the rate of range expansion from localized population centers. The green mussel, Perna viridis, was introduced to the waters of the Caribbean and Florida from the Indo-Pacific and remains relatively isolated in portions of northeastern Florida. The present study aimed at identifying the factors that influence the spatial and temporal patterns of green mussel larval settlement throughout the Intracoastal Waterway (ICW) of northeastern Florida, and to estimate dispersal distance using both field observations and a hydrographic model. Green mussel spat were collected from sites within the ICW on a monthly basis for much of 2007, 2008 and 2010 and a particle tracking model was used to predict larval movement during observed settlement periods from 2007. Settlement typically occurred during the summer months and was correlated to water temperature but not salinity or chlorophyll a concentration. Habitat also significantly influenced settlement patterns since most of the settlement occurred within the main channel of the ICW and not in adjacent feeder creeks. Observed settlement patterns suggested that most green mussel larvae likely dispersed 10 km or less but some were collected a minimum of 18 km from a potential source population. Model projections suggested that dispersal distance could often exceed 100 km but most of the particles dispersed along the coast as opposed to remaining within the ICW making comparisons between the model results and the observed settlement patterns difficult.