IS FISH SPECIES RICHNESS AT SITES IN THE CANADIAN GREAT-LAKES THE RESULT OF LOCAL OR REGIONAL FACTORS

We tested the hypothesis that fish species representation at Canadian Areas of Concern (AOC) is similar to that at other Great Lakes locatio ns. Clustering of fish species presence-absence from electrofishing da ta for 15 AOCs, data collected by a variety of methods and stored in t he Ontario Fish Species Distribution Data System for the 15 AOCs and f or 12 non-AOC sites indicated that (1) Fish Species Distribution Data System species lists were longest and electrofishing species lists wer e shortest at AOCs; (2) species lists were longer for AOCs than non-AO Cs; (3) only two site groups occurred in the Great Lakes; (4) species patterns follow a lower to upper lakes pattern that relates closely to the regional groupings previously interpreted in relation to postglac ial dispersion; (5) particular species were not key elements in contri buting to site groupings; and (6) clustering of sites by chemical and physical characteristics and by perturbation produced groupings that d iffer from site groupings by fish species assemblage. From these analy ses we infer that fish species representation at a location in the Gre at Lakes is primarily related to regional and biogeographical factors and that remediation at AOCs may contribute little to changing local s pecies richness.