Owl River Fish Community, Aquatic Habitat Assessment, and Riparian Enhancement 2022: Supplement to the 2021 Owl River Riparian Restoration and Enhancement Project Monitoring Report
Lindsay Dowbush, Lance Engley, and Mike Rodtka
Syncrude Canada Ltd. (Syncrude) recently proposed to expand its operations at the Mildred Lake site, collectively described as the Mildred Lake Extension Project (MLX). The Owl River Project, described herein, is one of two Department of Fisheries and Oceans (DFO) authorized offsets for the MLX Project. This MLX offset builds on related habitat offset and restoration activities already conducted on the Owl River by Alberta Conservation Association (ACA) on behalf of Syncrude from 2011–2017 for the Base Mine Lake Project.
To satisfy requirements of the DFO authorization, Syncrude is required to conduct monitoring on several attributes of the Owl River: i) riparian habitat; ii) water quality and instream habitat; iii) macroinvertebrates; and iv) resident and migratory fish. In 2021, ACA, on behalf of Syncrude conducted surveys to address these requirements. However, due to abnormally low water levels in 2021, we deferred the fish community and aquatic habitat assessment to 2022. In this supplemental report, we present results from the 2022 fish community and habitat surveys, as well as updates on riparian enhancement and livestock exclusion areas. Our study area extended 46 km upstream from the mouth of the Owl River at Lac La Biche and included portions of two tributary streams of the Piche River and Square Creek.
The fish community in the Owl River system during our survey consisted of five species: walleye (Sander vitreus), white sucker (Catostomus commersonii), yellow perch (Perca flavescens), northern pike (Esox Lucius), and burbot (Lota lota). Walleye was the most abundant species, occurring at all sampling sites along the Owl River but not on the Piche River site. Yellow perch and white sucker occurred along much of the length of the Owl River, as well as the Piche River; northern pike occurred sporadically within the study area. Four of the 134 fish captured (two walleye and two white suckers) had tumours or lesions. The three most abundant species, walleye, white sucker, and yellow perch, ranged in size from 58 to 627 mm, 36 to 477 mm, and 33 to 135 mm, respectively; sampled individuals of all three species exhibited good condition (K>1.0). Fish community composition and aquatic habitat information generated through this project will be used as a baseline for monitoring of potential outcomes of restoration and protection of degraded riparian zones along the river. Dominant substrate was large gravel in the most upstream site and transitioned to sand, then fines as sites progressed downstream. Instream fish habitat cover was mostly due to a combination of turbid waters and aquatic vegetation.
In 2022, we contacted all eleven landholders in the Owl River Project area. We signed three new 25-year Riparian Habitat Enhancement Agreements. Combined, these new agreements protect 79.63 hectares (ha) of riparian habitat and 7.37 km of riverbank along the Owl River, bringing the total protected riparian habitat to 104.93 ha and total protected riverbank to 11.74 km since this project was initiated in the fall of 2020.