Its Oh-fish-al! Lake Windermere and Columbia Lake’s 2021 Shoreline Fisheries Assessment Results Are In

In 2021 the Lake Windermere Ambassadors and Columbia Lake Stewardship Society partnered with Lotic Environmental Ltd. to research the fish populations of Lake Windermere and Columbia Lake. Sample sites were chosen to represent different habitat types and disturbance levels and to facilitate comparisons to a previous shoreline fisheries assessment completed in 2007.

Fish populations are affected by multiple factors including but not limited to; warming waters, habitat disturbance, angling pressure and increasing urbanization (Hildebrand, 2022). With these facts in mind, it is interesting to read through the 2021 shoreline fisheries assessment and look at the species of fish most commonly identified in Lake Windemere. However, it is important to note that research over multiple seasons and likely years would be required to accurately determine if the changes in fish populations between the 2007 and 2021 surveys represent actual changes or natural variation (Hildebrand, 2022).

The 2021 survey identified Northern Pikeminnow as the most common species in Lake Windermere, representing 40.9% of fish identified. In the 2007 survey, Northern Pikeminnow accounted for less than 5.2% of fish identified. Northern Pikeminnow are native to Lake Windermere but known to be voracious predators, often out-competing more sensitive native species, especially in warmer waters. The 2021 survey also found that Northern Pikeminnow were common in habitats of all disturbance levels. However, they were about three times as common in highly disturbed sites than in sites with moderate or low disturbance levels. In contrast, other native fish, such as Mountain Whitefish, Redside Shiner and Peamouth Chub, appeared to prefer sites with low disturbance levels.

Largemouth bass were the second most common fish in Lake Windermere, accounting for 33.9% of fish identified in the 2021 survey. Largemouth bass is a non-native species introduced to Lake Windermere many years ago for sport fishing. Like Northern Pikeminnow, they are better suited to warmer waters and can out-compete or displace many native species that require cool, deep waters.

Though we cannot draw any firm conclusions from comparing the 2007 and 2021 study results, it offers us some important insights. This information will be valuable for future work in designing further surveys and forming hypotheses about changes that could be happening in Lake Windermere’s fish populations.  

Swim on over to our “Documents and Reports” page at Lakeambassadors.ca to read the report! A huge thank you to our funders who supported us on this study: Columbia Valley Local Conservation Fund, Columbia Basin Trust, Columbia Valley Community Foundation, BC Hydro, The Regional District of East Kootenay, and The District of Invermere.

Do you fish Lake Windermere in the fall? We would love to hear what fish you catch! Please fill out our community fish survey at www.surveymonkey.com/r/XZG7N6T

 

Table 5 taken from the 2021 Shoreline Fisheries Assessment Final Report – During the summer of 2007, 133 Cyprinids were recorded but not identified to species. It is considered likely that Northern Pikeminnow and Peamouth Chub were among the Cyprinid species recorded in 2007. Additional research is needed to determine if the differences between years was due to natural variation, the primary sample methods used (snorkel surveys in 2007; beach seining in 2021), or represent actual changes to the species assemblage and numbers of fish in Lake Windermere (Hildebrand, 2022).