Patterns in the species composition of fish assemblages among Wisconsin streams

Abstract

SynopsisTo better understand patterns of fish assemblage composition in Wisconsin streams in relation to major environmental gradients, I carried out multivariate direct gradient analysis (canonical correspondence analysis) of two large independent datasets on fish species abundance in Wisconsin streams. Analysis of the two datasets yielded similar results, suggesting that observed patterns and relationships were real. Stream sites were distributed along fish species-environment gradients, but segregation into distinct stream temperature and geographic groups was also evident. The strongest gradient in both datasets was related to summer water temperature patterns, and encompassed a transition from small, coldwater streams dominated by salmonids, cottids, certain cyprinids, and few other species, to both small and large, warmwater streams dominated by a high diversity of different cyprinids, catostomids, ictalurids, centrarchids, and percids. A second gradient in both datasets was complex but largely geographic. Within it, sites from each of the four ecoregions that occupy Wisconsin formed fairly discrete groups. The strongest differences were between sites in the two southern Wisconsin ecoregions, the Driftless Area and the Southeastern Wisconsin Till Plains, that were dominated by certain cyprinids, ictalurids, and centrarchids, and sites in the two northern Wisconsin ecoregions, the North Central Hardwood Forests and the Northern Lakes and Forests, that were dominated by a different set of cyprinids and ictalurids, plus some petromyzontids, salmonids, catostomids, and percids. Sites from the Driftless Area that were mostly higher-gradient (steep stream slope) and had many riffle-dwelling species could also be distinguished from sites in the Southeastern Wisconsin Till Plains that were mostly lower-gradient and had many pool-dwelling species. The patterns of fish assemblage composition among sites and the associated fish species-environment relationships that were revealed by the analyses provided a framework for developing an ecologically meaningful hierarchical classification of Wisconsin stream sites based on stream thermal regime, ecoregion, stream size, and stream gradient. Introductionserve and manage fish assemblages over such a broad scale requires a detailed understanding of Landscapes on the geographic scale of a US state or both the patterns of fish assemblage composition Canadian province contain a huge amount and diand distribution within and among water bodies, versity of surface waters, with a wide variety of fish and the nature of the major environmental graassemblages inhabiting them. To effectively condients that cause, or at least explain, these patterns

Physical Habitat and Fish Assemblage Relationships with Landscape Variables at Multiple Spatial Scales in Wadeable Iowa Streams

“…We observed a catchment area gradient in fish assemblages, as has been documented previously (Schlosser 1982;Lyons 1996). Fish assemblages in small headwater streams tend to be small-bodied, generalist invertivores.…”

Fish larvae assemblages in two floodplain lakes with different degrees of connection to the Paraná River, Brazil

“…Sites S2 and X2 are located in the wider portions of the lakes, where the influences of the margins and the vegetation are not so evident. This shows that the establishment of fish communities is strongly influenced by local processes present in the environment (Lyons, 1996;Agostinho et al, 1997b).…”

Effects of natural and anthropogenic environmental changes on riverine fish assemblages: a framework for ecological assessment of rivers

“…Most common way is to select the reference sites that are "minimally disturbed" because pristine conditions no longer exist in most industrialized countries and coming back to prehistoric conditions first, will deny the place of humans in the landscape (Norris and Thoms, 1999) and second, will make restoration goals obsolete because obviously not attainable. Huet, 1959;Sheldon, 1968;Bussing and Lopez, 1977*;Sydenham, 1977*;Horwitz, 1978;Lauzanne and Loubens, 1988*;Angermeier and Karr, 1983*;Winemiller, 1983*;Mahon, 1984;Balon et al, 1986;Hugues and Gammon, 1987;Beecher et al, 1988;Matthews and Robinson, 1988;Paugy et al, 1988*;Ibarra and Stewart, 1989;Hugueny, 1990*;Lyons and Schneider, 1990*;Osborne and Wiley, 1992;Winemiller and Leslie, 1992*;Oberdorff et al, 1993;Lyons, 1996;Belliard et al, 1997;Maret et al, 1997;Mastrorillo et al, 1998;Kamdem-Toham and Teugels, 1997*;Mérigoux et al, 1998*;Angermeier and Winston, 1998;Matthews and Matthews, 2000;Tejerina Garro, 2001* Mérona, 1981* River gradient Huet, 1959Lyons, 1996;Maret et al, 1997;Mastrorillo et al, 1998;Waite and Carpenter, 2000;Oberdorff et al, 2001ª…”