Seasonal migrations and reproductive patterns in the lake sturgeon, Acipenser fulvescens, in the vicinity of hydroelectric stations in northern Ontario |
| |
Authors: | Scott McKinley Glen Van Der Kraak Geoff Power |
| |
Institution: | (1) Department of Biology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada;(2) Axelrod Institute of Ichthyology and Department of Zoology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada |
| |
Abstract: | This study was conducted in order to evaluate seasonal migratory behaviour and reproductive pattern of lake sturgeon in a
confined region of the Mattagami River system in northern Ontario where river flow is regulated by hydroelectric works. Radio
tracking and the systematic sampling of lake sturgeon using gill nets indicated that the distribution of fish throughout the
study site varied on a seasonal basis. This distribution was related to the migration of individuals to potential spawning
sites in the spring, a post-spawning dispersal to feeding areas and late summer migration to an area of concentration on the
Groundhog River which is a tributary of the Mattagami River. There was a high proportion of fish (about 50%), within the size
range of reproductively active fish, found in the vicinity of suitable spawning habitat during early May. Measurement of the
gonadosomatic index (GSI) and plasma sex steroid hormone levels revealed a divergent pattern of reproductive development between
the sexes. Female sturgeon exhibited a prolonged period of ovarian regression following spawning. Resumption of ovarian development
was not evident until September and was characterized by an increased GSI and plasma levels of testosterone and 17β-estradiol.
In contrast, male lake sturgeon began testicular recrudescence within one month of spawning with the GSI reaching prespawning
levels by September; reproductive hormones were at prespawning levels by the end of June. It seems that hydroelectric works
has complex effects on sturgeon in the Mattagami system. The extensive migratory behaviour of lake sturgeon within the study
area make it prone to impingement or entrainment whereas the altered river flow appears to enhance reproductive development.
This revised version was published online in August 2006 with corrections to the Cover Date. |
| |
Keywords: | reproduction radio telemetry hydroelectric development gonadosomatic index sex steroid hormones |
本文献已被 SpringerLink 等数据库收录! |
|