LE3 .A278 2020

2020

Stokesbury, Michael

Acadia University

Master of Science

Masters

Biology

Biology

Natal-river philopatry is a common trait across anadromous fish taxa, with iteroparous species returning to their rivers of origin multiple times over the course of their lives. Some straying occurs in most populations, as individuals venture beyond expected migratory paths and colonize new rivers or mix with established populations. From May 2013 to June 2019, we tagged 9270 upstream-migrating adult alewifeAlosa pseudoharengus (Wilson, 1811) in four rivers as part of a study examining the efficiency of local fishways in rivers tributary to Cumberland Basin, Inner bay of Fundy. Fish passage efficiency at obstruction bypass structures like fishways is an important parameter in ensuring conservation of anadromous fish stocks. A total of 5919 tagged fish were detected by antenna arrays installed on the four rivers being monitored, with 1036 individuals detected on rivers other than the ones on which they were tagged. By comparing straying with fish age, sex, and proximity of destination rivers, we calculated howthese va riables influenced the migration choices of spawning alewife. To test the effect of artificial illumination on fish passage use by alewife, we illuminated one of two Denil-style fishways in the 2014 season and found that illumination had a negative effect on fish presence within the fishway.

The author retains copyright in this thesis. Any substantial copying or any other actions that exceed fair dealing or other exceptions in the Copyright Act require the permission of the author.

https://scholar.acadiau.ca/islandora/object/theses:3485