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Effectiveness of Spawning Substrate Enhancement for Adfluvial Fish in a Regulated Sub-Arctic River
  • Mark Poesch,
  • M. Miller,
  • Cameron Stevens
Mark Poesch
University of Alberta Faculty of Agricultural Life and Environmental Sciences

Corresponding Author:[email protected]

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M. Miller
Northwest Territories Power Corporation (NTPC
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Cameron Stevens
WSP Canada Inc
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This study was conducted to meet regulatory requirements under the Fisheries Act in Canada, specifically for a hydroelectric facility on the Yellowknife River in the Northwest Territories. The research focused on annual snorkel surveys of adfluvial fish and their spawning habitat below the facility. Initial observations of egg mortality, potentially due to overcrowding, prompted the investigation of natural and enhanced habitat for spawning Lake trout ( Salvelinus namaycush), lake whitefish ( Coregonus clupeaformis) and cisco ( Coregonus artedi) from 2016 to 2019. The design and composition of the installed habitat were based on fish utilization of the natural channel below the hydro facility and design principles from previous habitat rehabilitation projects for anadromous fishes. Pre- and post-enhancement data on egg density and survival were collected using 1 m 2 plots on both natural and artificially enhanced substrates. Three years of post-enhancement monitoring indicated higher egg densities and a greater proportion of live eggs in the artificially enhanced habitat compared to the natural habitat, with more pronounced trends observed for coregonids (lake whitefish and cisco) compared to lake trout. These findings suggest that habitat enhancement has the potential to enhance juvenile recruitment for adfluvial fish. A critical factor in the design was the substrate composition, providing adequate interstitial spaces for egg development and protection. This study represents the first documented attempt at habitat improvement in a regulated sub-Arctic river in Canada. The findings offer valuable guidance for stakeholders involved in new or existing development projects that require conservation actions to maintain fisheries productivity.
14 Jul 2023Submitted to River Research and Applications
18 Jul 2023Submission Checks Completed
18 Jul 2023Assigned to Editor
19 Jul 2023Review(s) Completed, Editorial Evaluation Pending
24 Jul 2023Reviewer(s) Assigned
03 Oct 2023Editorial Decision: Revise Minor
18 Mar 2024Review(s) Completed, Editorial Evaluation Pending
18 Mar 2024Editorial Decision: Revise Minor