| Electrofishing data were collected and assessed to characterize fish communities with respect to water temperature and habitat quality in River Philip, Nova Scotia. Based on an Index of Biological Integrity (IBI), I developed an Index of Sustainable Coldwater Streams (ISCS) to assess and monitor fish communities in coldwater streams. These findings were used to make recommendations for fish conservation planning in the watershed. With increasing water temperature and decreasing habitat quality, species replacement occurred in the following order: brook trout (Salvelinus fontinalis ), brown trout (Salmo trutta), sea lamprey ( Petromyzon marinus), Atlantic salmon (Salmo salar), three-spine stickleback (Gasterosteus aculeatus), white sucker (Catostomus commersoni), and several cyprinid species (e.g., blacknose dace (Rhinichthys atratulus) and creek chub ( Semotilus atromaculatus)). The changes in the fish communities were suspected to have occurred by a combination of natural and anthropogenic influences; the observed downstream increase in water temperature was attributed to the natural longitudinal change and increased human development. The ISCS was intended to quantify these fish community changes, with the coldest and minimally impacted streams being the reference condition. (Abstract shortened by UMI.)... |
