Major changes in fish thermal habitat diversity in Canada's Arctic lakes due to climate change

• Main Authors: Gillis, Daniel, Minns, Charles, Campana, Steven, Shuter, Brian
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2024
• Subjects: Arctic; Lakes; water temperature; lake stratification; Ice Phenology; Climate change; Fish habitat; Thermal Ecology; Thermal Guild; modelling
• Online Access: https://doi.org/10.5061/dryad.cvdncjt8g

Climate warming is a major disruptor of fish community structure globally. We use large-scale geospatial analyses of 447,077 Canadian Arctic lakes to predict how climate change would impact lake thermal habitat diversity across the Arctic landscape. Increases in maximum surface temperature (+2.4–6.7 °C), ice-free period (+14–38 days), and thermal stratification presence (+4.2–18.9%) occur under all climate scenarios. Lakes, currently fishless due to deep winter ice, open up; many thermally uniform lakes become thermally diverse. Resilient coldwater habitat supply is predicted; however, thermally diverse lakes shift from providing almost exclusively coldwater habitat to providing substantial coolwater habitat and previously absent warmwater habitat. Across terrestrial ecozones, most lakes exhibit major shifts in thermal habitat. The prevalence of thermally diverse lakes more than doubles, providing refuge for coldwater taxa. Ecozone-specific differences in the distribution of thermally diverse and thermally uniform lakes require different management strategies for adapting fish resource use to climate change. Spreadsheet editor to view files (e.g., Microsoft Excel). R to execute code. Funding provided by: Natural Sciences and Engineering Research Council Crossref Funder Registry ID: https://ror.org/01h531d29 Award Number: Overview of the Methods Used in This Paper The following is an overview of the methods that we used in this paper. Each paragraph has an accompanying sub-section within the Methods section that provides more details. To develop the approach used in this paper, we applied both empirical and semi-mechanistic methods to build the set of predictive models needed to fulfill our primary objective: (i) predicting the impacts of climate change on the seasonal progression of thermal structure in Canadian Arctic lakes: and (ii) assessing how those impacts would change the character and diversity of the fish communities resident in those lakes 24,35 . A summary of issues addressed, and methods used ...