Influence of dams and habitat condition on the distribution of redhorse (Moxostoma) species in the Grand River watershed, Ontario |
| |
Authors: | Scott M Reid Nicholas E Mandrak Leon M Carl Chris C Wilson |
| |
Institution: | (1) Watershed Science Centre, Trent University, 1600 West Bank Drive, Peterborough, ON, Canada, K9J 7B8;(2) Great Lakes Laboratory for Fisheries and Aquatic Sciences, Fisheries and Oceans Canada, Burlington, ON, Canada, L7R 4A6;(3) United States Geological Survey, Great Lakes Science Center, Ann Arbour, MI 48105-2807, USA;(4) Aquatic Research Section, Ontario Ministry of Natural Resources, Trent University, Peterborough, ON, Canada |
| |
Abstract: | Redhorse, Moxostoma spp., are considered to be negatively affected by dams although this assertion is untested for Canadian populations. One
hundred and fifty-one sites in the Grand River watershed were sampled to identify factors influencing the distribution of
redhorse species. Individual species of redhorse were captured from 3 to 32% of sites. The most widespread species were golden
redhorse, M. erythrurum (30%) and greater redhorse, M. valenciennesi (32%), while river redhorse, M. carinatum, was only found along the lower Grand River. Redhorse were absent from the highly fragmented Speed River sub-watershed and
upper reaches of the Conestogo River and the Grand River. Redhorse species richness was positively correlated to river fragment
size and upstream drainage area. Generalized additive models (GAMs) were applied to evaluate the influence of river fragment
length, connectivity and habitat on species distribution. Principal component analysis reduced habitat data to three axes
representing: channel structure, substrate, and pool, riffle and run habitats (PC1); gradient and drainage area (PC2); and
cover (PC3). GAMs indicate that PC2 was important for predicting black redhorse and greater redhorse site occupancy and PC1
was important for golden redhorse. River fragment length was important for predicting site occupancy for shorthead redhorse,
but not other species. |
| |
Keywords: | Habitat fragmentation Rivers Species at risk General additive models |
本文献已被 SpringerLink 等数据库收录! |
|