Title: Differences in rheotactic response between two strains of brook trout (Salvelinus fontinalis) and differences in rheotactic response between two age groups of fish.

Student: Katie Renschen

Advisor(s): Derek Ogle

Collaborator(s): Henry Quinlan and Mark Brouder (U.S. Fish and Wildlife Service - Ashland National Fish and Wildlife Conservation Office); Dale Bast and Kurt Schilling (USFWS - Iron River National Fish Hatchery); and William Ardren (USFWS - Lake Champlain Fish and Wildlife Resources Office).

Abstract: Rheotactic response was studied between two age groups and two strains of coaster brook trout Salvelinus fontinalis to determine if there are life history differences between the strains and differences in rheotactic behaviors at different ages. An inlet-spawning strain (Siskiwit Bay) and a shoreline-spawning strain (Tobin Harbor) were compared in identical artificial stream environments. The two strains were compared as "sac-fry" and again as "swim-up fry." Fish were left in the stream channels for a period of 24 hours, then their movements were categorized as upstream, downstream, or neither. The "sac-fry" of both strains did not exhibit much movement in the tanks, but there was a significant statistical difference in the rheotactic responses between the two strains of the older "swim-up fry." Between 12.4 and 33.5 percent more Tobin Harbor "swim-up fry" than Siskiwit Bay "swim-up fry" moved downstream. These differences may imply that there are variations in life history between strains, and that discretion should be used when choosing a strain for management purposes.

Other: Final Paper (PDF 128 kb)
Presentation to Northland AFS Sub-Unit (PPT 5.4 mb)