Predicting Risks of Invasion of Caulerpa Species in Florida

GLARDON, Christian/G.*; WALTERS, Linda/J.; QUINTANA-ASCENCIO, Pedro; WEISHAMPEL, John/F.; MCCAULEY, Lisa; Univ. of Central Florida, Orlando; Univ. of Central Florida, Orlando; Univ. of Central Florida, Orlando; Univ. of Central Florida, Orlando; Univ. of Central Florida, Orlando: Predicting Risks of Invasion of Caulerpa Species in Florida

The introduction of non-native animals and plants is a major threat to biodiversity, with dramatic effects on productivity and habitat structure. In 1984, Caulerpa taxifolia � aquarium strain, was released, probably as waste, into Mediterranean waters. It rapidly spread from an initial patch of about one meter square to over 13,000 ha, where it has overgrown all native flora and fauna, impacting fisheries and tourism in coastal communities. Florida is an area that closely matches the environmental conditions of invaded areas and, thus, is likely to be invaded in the near future. Our research focuses on the creation of ArcGIS maps to estimate the current distribution of the genus Caulerpa around Florida. Particular attention is given to the distribution of the potentially invasive species of this genus, including C. taxifolia, C. brachypus and C. racemosa. I surveyed 24 randomly chosen areas in each of 6 zones selected in a stratified manner along the Floridian coastline to evaluate the association of indicators that are potentially descriptive of the environment with Caulerpa occurrence. Temperature ranges, presence or absence of seagrass beds, human population density, and proximity to marinas were chosen as the 4 parameters expected to correlate to Caulerpa occurrences. A logistic regression model assessing the association of Caulerpa occurrence with measured variables is being developed to predict current and future probabilities of Caulerpa �hot spots� throughout the state; this will allow us to focus on particular areas for future surveys.

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