An Evaluation of Changes in the White Perch
(Morone americana) Population of Grafton Lake, Kejimkujik
National Park After Dam Removal
SUMMARY
During the period between July 1993 and September 1996, numerous studies were carried out to examine the physical, chemical and biological changes resulting from removal of the dam at Grafton Lake, Kejimkujik National Park. As part of these studies, several fish surveys were carried out to assess the changes occurring in the more dominant fish populations of the lake. The data collected during these surveys, however, was never fully analyzed with respect to evaluating what, if any, changes had occurred after removal of the dam. To partially remedy this deficiency, as well as provide a database spanning a longer time-period, a survey of the white perch (Morone americana) population was carried out in 2001, and the results of all surveys were subjected to a comparative analysis.
The results of the analyses suggest that little change has occurred in either growth rate or condition of the white perch population. This is in contrast to an earlier study that provided evidence of significant changes in the yellow perch population of Grafton Lake following removal of the dam. Possible reasons for the different responses observed for the two species studied include differences in habitats and life styles between the two species.