Environmental effects and fish community structure.

PERMANOVA results from the model fish ~ exposure + distance + population, stratified by year and terms added sequentially (first to last). Df = degree(s) of freedom, SS = Sums of Squares, MS = Mean Squares, F = F statistic obtained from the model, R² = coefficient of determination, and p = probability of the obtained (model) F exceeding the predicted F statistic by chance.