Developing an Index of Sustainable Coldwater Streams Using Fish Community Attributes in River Philip, Nova Scotia
MacMillan, John Leland
MetadataShow full item record
An Index of Sustainable Coldwater Streams (ISCS) was developed to quantify fish community changes affected by water temperature and physical habitat quality for small streams in the River Philip Watershed, Nova Scotia. The ISCS was modified from an Index of Biotic Integrity (IBI) and intended for assessing the quality of streams as coldwater habitats. The calibration of the ISCS was thought useful since global warming and habitat degradation, two major aquatic threats in the coming era, could significantly reduce the amount of undisturbed coldwater streams in Nova Scotia; thus, a tool was necessary to identify fish species vulnerable to these threats and to monitor fish community changes in relation to water temperature and physical habitat quality. There was a strong negative correlation between water temperature and physical habitat quality, and water temperature increase and habitat degradation replaced coldwater fish assemblages dominated by salmonids with warmwater and/or tolerant fish assemblages, coupled with increased total species richness. The proposed ISCS is composed of five metrics: (1) number of fish species, (2) percent of individuals that are salmonids, (3) percent of individuals that are brook trout (Salvelinus fontinalis), (4) percent of individuals that are white sucker (Catostomus commersoni), and (5) percent of individuals that are catchable salmonids (age 2 years and older). The ISCS is a promising index to identify priority conservation areas and to monitor changes in aquatic environments.