Predictive ecological niche modeling in aquatic systems

Predictive ecological niche modeling [ENM] in terrestrial systems has produced interesting and innovative work. Application of these methods in aquatic systems would lead to similar advances in aquatic biodiversity research. Herein, ENM is applied to predicting the distributions of some freshwater fishes, testing for evidence of ecological niche conservatism in North American freshwater fishes, and predicting invasive potential in the U.S. for a variety of European fishes. Initial analyses test the efficacy of ecological niche modeling for predicting fish species' potential distributions using an artificial-intelligence algorithm, the Genetic Algorithm for Rule-Set Prediction [GARP]. Models of species' ecological niches are developed using GARP, and projected onto geography to predict species distributions for twelve fishes from Kansas. Models were tested with independent validation data using Receiver Operating Characteristic [ROC] analyses. Of the species tested, all were statistically significant with the models showing excellent predictive ability. Omission errors across taxa ranged from 0--17%.; Ecological niche modeling is then used to look for evidence of ecological niche conservatism in 6 clades of freshwater fishes. This is achieved by evaluating reciprocal predictivity of distributional predictions made based on ecological niche models developed for each individual taxon in a clade. Omission percentages, total and average commission, and ROC analyses were calculated to evaluate predictive ability. Ecological niche conservatism was found generally across the starheaded topminnows, the sand darters, and the N. longirostris species group. There was some inter-predictivity within the N. rubellus group, but almost no inter-predictivity within the black basses, indicating a lack of conservatism for the niche parameters investigated. These results demonstrate that ecological niches act as stable constraints on freshwater fish distributions.; Ecological niche modeling was then used to predict invasive potential for 27 species of European freshwater fishes that are either currently, or are proposed to be, imported into the United States. Ecological niche models were developed using native range data for each species, and subsets of the native range data were used to validate models. Models were then projected onto the conterminous United States to visualize the invasive potential for each species.