Patterns in fish species composition across the interface between streams and lakes

Publisher Website
Google Scholar
Abstract
We compared fish species compositions among four site types (lake, lake mouth, stream mouth, stream) along the gradient from stream to lake for 12 tributary mouths. Comparison of species richness, rarefaction species diversity, and species density all supported the same pattern: stream-mouth sites contained the highest number of species, followed by stream sites, lake-mouth sites, and lake sites, even though lake and lake-mouth sites yielded more individuals and were larger in area and volume. Principal components analysis formed three clusters of mixed sites based on similarities in dominant fish species rather than designations of lake, lake mouth, etc. Rank order assemblage tests revealed that species composition of tributary-mouth sites was similar in only one quarter of the systems sampled; other systems showed a transition from "lake" to "stream" species compositions at or near the tributary mouth. Species assemblage comparisons within site types between systems revealed low consistency in the composition of stream-mouth sites and high consistency for the other site types. We concluded that the tributary mouth fits the definition of an ecotone and speculate that the difference in hydrologic and geomorphic properties of streams and lakes played a role in the patterns that we saw on either side of the tributary mouth.

This publication has 0 references indexed in Scilit: