Abstract
Previous studies have found lower levels of genetic variation in lake than stream populations of brook trout (Salvelinus fontinalis). We test the generality of this observation by examining whether brook trout genetic variation at 10 allozyme loci differed within and among 9 pairs of lake and adjacent stream populations. With one exception, we found that lake populations had lower heterozygosity than their adjacent stream populations. Although the lakes in this study are small and some have had documented fish mortality events, no association was found between lake size characteristics and the degree of difference in heterozygosity between lakes and their adjacent stream populations. There were, however, negative associations between metrics of fishing mortality and the difference in heterozygosity between lakes and their adjacent stream populations. The greater the estimated fishing pressure on lake-dwelling trout, the greater the reduction in heterozygosity in those populations relative to their adjacent stream populations. We interpret our findings to suggest that intensive fishing pressure can significantly reduce genetic variation. Managers should therefore prevent human-induced mortality at any indication of a large natural mortality event to allow populations to increase in size as rapidly as possible following a decline.
| Original language | English |
|---|---|
| Pages (from-to) | 245-256 |
| Number of pages | 12 |
| Journal | Conservation Genetics |
| Volume | 2 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2001 |
Bibliographical note
Funding Information:The assistance of Reagan Sutherland in the summer of 1996 is gratefully acknowledged. Additional help by Shirley Humphries, Alain Caissie, Yves Lanteigne, George Sinclair, Sedgewick Sinclair, and Nancy Mason is much appreciated; Shirley Humphries also kindly provided the 1999 Tracey Lake population size estimate. We thank Doug Clay for his support of this project. Tom Pettigrew (New Brunswick Department of Natural Resources and Energy) provided information regarding lake size, depth, angling pressure and stocking history and without whose advise and gill nets, collection of brook trout outside of Fundy National Park would not have been possible; Peter Cronin and Charles Ayer (NBDNRE) provided the stocking history for the lakes outside Fundy National Park. Fish collections were conducted inside Fundy National Park with Parks Canada collection permits and outside the park with Department of Fisheries and Oceans permits. These collections also required the consent and assistance of Lawrence McFarlane and Alison Forsythe (Pleasant Lake Fishing Club), Reginal McKenzie (Chisholm Fishing Club – Dick’s Lake), and Burt Miller and Edwin Patterson (Hampton Fishing Club – Wood Lake). Comments by Rick Cunjak, Julian Dodson, Christophe Herbinger, Mark Johnston, Pat O’Reilly and 2 anonymous reviewers led to a much improved manuscript; insight by Mark Johnston at the planning stages of this project led to the paired sampling scheme employed. This work is funded by Parks Canada through Science Advisory Board research grants to Fundy National Park and by NSERC Research Grants to Jeff Hutchings and Roy Danzmann.
ASJC Scopus Subject Areas
- Ecology, Evolution, Behavior and Systematics
- Genetics
