Globally, fishes have the highest rate of discovery of new species and exist in greater numbers than all other vertebrates combined. However, over the course of only a few decades the amount of inland fishes in North America considered imperiled or extinct has increased 20-40%. The main threats contributing to the decline in diversity of North American fresh water fishes include destruction of habitat, water depletion, point and non-point source pollution, erosion and sedimentation, overexploitation, disease and parasitism, introduced species, and climate change. The five sampling locations included in this study were positioned downstream the Shanango River Lake. All sampling sites were located south or downstream of the Shenango River Tailwater dam near Shapesville, PA and all are within the Shenango River watershed. Overall twenty fish species and 725 fish have been sampled from the five locations over a two year period.
Tags: Biologie, Ökologie
Taschenbuch - 9783639369779 Verlag: VDM Verlag Ersterscheinung: Juli 2011 ISBN-13: 9783639369779 Größe: 220 mm x 150 mm x 6 mm Gewicht: 153 Gramm 92 Seiten Versandfertig in 3-5 Tagen.