PARENT SESSION
Contributed Oral Session 119: Invasive Species : Aquatic Invaders
Thursday, August 11, 8:00 AM - 11:30 AM, Meeting Room 520 A, Level 5, Palais des congrès de Montréal
Forecasting the distribution of the invasive New Zealand mudsnail in North America.
Loo, Sarina*,1, 1 Monash University, Melbourne, Australia
ABSTRACT- Invasive species have been predicted to be the second greatest driver of freshwater species loss over the next century. An understanding of the potential distribution of aquatic invaders contributes to the evaluation of the environmental, economic and social costs of invasive species. The invasive New Zealand mudsnail, Potamopyrgus antipodarum , is rapidly spreading in the western USA and has been reported in the Great Lakes. The snail is also a successful invader of streams and rivers in Australia and Europe. The New Zealand mudsnail has been reported to occur in densities of up to 800 000 per m2 , may outcompete native macroinvertebrates for resources and have ecosystem-level impacts. To assess the potential distribution of the snail in North America, I used the Genetic Algorithm for Rule-set Production (GARP) modelling framework. GARP performs a spatially explicit ecological niche modelling analysis to predict the potential distribution of a species, based on known records of the species' occurrence. Three models for North America were built using distributional datasets from either 1) the snail's native range in New Zealand, 2) its invaded range in Australia, or 3) its invaded range in Europe. The model outputs were compared to the current invaded range in North America. Each model forecasted different potential distributions and I explored the environmental predictor variables that influence the snail's distribution on each continent as a reason for the model differences. Despite variation among the spatial distribution models, they generally forecast an expansion in the New Zealand mudsnail's range across the northeastern and western regions of North America.
Key words: freshwater biological invasion, spatial distribution models, New Zealand mudsnail, Genetic Algorithm for Rule-set Production (GARP)