Investigating the fish community of the Rideau River, Ontario, with respect to historical changes and current land-use practices.

Abstract

Agricultural and urban development incites change in aquatic ecosystems. It is generally hypothesized that change due to agricultural and urban development modifies the aquatic habitat characteristics, which ultimately affect the fish communities. The first objective of this study was to describe the appearance and disappearance of fish species within the Rideau River. Scientific literature, museum archives, newspaper articles, historical atlases, municipal reports, and anecdotal reports were consulted to reconstruct the past 120 years of the fish community. The results indicated that the diversity of fish species increased as a result of fish introductions, through increased boat tragic, fish stocking, transient species, baitfish introductions, live-well dumping and the introduction of exotics. The second objective of this study was to determine whether diversity and abundance of fish in the Rideau River could be attributed to agricultural, urban, or forested land-use type. In order to determine this, the fish community was intensively sampled in each of the three habitat types utilizing various sampling gear (trapnets, seines, backpack electrofisher). Over 9000 fish belonging to 33 species were captured between mid-July through mid-September 1998 and 1999. It was found that fewer species were captured in urban areas as compared to agricultural or forested areas and that the abundance of fish was higher in agricultural areas. Also, land-use was correlated with habitat characteristics and habitat characteristics were correlated with fish community diversity and abundance.