Meeting Abstract

S3-3  Monday, Jan. 4 09:00  Projected dispersal and range expansion of a potentially invasive polychaete in South Africa DAVID, Andrew A*; MATTHEE, Conrad A; LOVEDAY, Benjamin R; SIMON, Carol A ; Clarkson University, Potsdam, NY; Stellenbosch University, Stellenbosch, South Africa; Plymouth Marine Laboratory, Plymouth, United Kingdom ; Stellenbosch University, Stellenbosch, South Africa adavid@clarkson.edu

A major goal of invasion biology is predicting the spread and range expansion of introduced species such as that of the polychaete, Boccardia proboscidea, along the South African (SA) coast. Since B. proboscidea was in its incipient stages of a potential invasion, the closely related, Polydora hoplura was used as a “proxy species”. To assess dispersal potential, a high-resolution circulation model of the SA coast was constructed and coupled to a particle-tracking model. The results showed limited connectivity between eastern and western boundaries, with Cape Point proving to be a prominent barrier. These results were in contrast to high genetic connectivity observed in a population genetic study conducted on P. hoplura. The discrepancy was likely due to the inability of genetic studies to detect anthropogenic dispersal. Furthermore, temperature had a significant effect on larval survivorship and developmental rate of both species under thermal regimes representative of the SA coast. Survivorship curves for the two species were similar where high mortality was observed at the extreme low (< 17&degC) and high temperatures (> 28&degC). P. hoplura’s response to the different temperature treatments was congruent with its current distribution and due to similar survivorship curves we predicted that B. proboscidea can potentially become established along the same stretch of coast though anthropogenic dispersal will be the determining factor for widespread dispersal.