Movement patterns and trophic structure of a reservoir fish community assessed using stable isotope analysis.

摘要

Pulp mill and municipal sewage effluents can affect fishes in many ways and environmental monitoring programs, often using a sentinel-species approach, have been developed to assess these effects. With applications to environmental monitoring studies in mind, the goals of my thesis were to use stable isotope analysis to determine fish community structure in the presence of pulp mill and sewage treatment plant effluents, and to assess the movements and site-fidelity of common fish species in this area of Mactaquac Lake at Nackawic, New Brunswick. My results indicate that pulp mill- and sewage effluent-exposed sites have lower species richness, abundance, and diversity. Fishes that are present show marked differences in trophic position and dietary sources than those at non-exposed reference sites. Yellow perch and white sucker showed high site-fidelity while white perch showed high inter-site movements. Brown bullhead and banded killifish showed intermediate or uncertain degrees of movement. These results suggest that the pulp mill effluent and municipal wastewater effluent do affect the fish communities, while yellow perch and white sucker would make the best sentinel species. The use of local reference sites is also supported for future studies at the pulp mill in Nackawic.