Using thermal limits to assess establishment of fish dispersing to high-latitude and high-elevation watersheds
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Full Publication: https://doi.org/10.1139/cjfas-2016-0051Product Type: Journal Article
Year: 2016
Authors: Dunmall, K. M., N. J. Mochnacz, C. E. Zimmerman, C. F. Lean, and J. D. Reist
Suggested Citation:
Dunmall, K. M., N. J. Mochnacz, C. E. Zimmerman, C. F. Lean, and J. D. Reist. 2016. Using thermal limits to assess establishment of fish dispersing to high-latitude and high-elevation watersheds. Canadian Journal of Fisheries and Aquatic Sciences 73(12):1750-1758. doi:10.1139/cjfas-2016-0051
Abstract
Distributional shifts of biota to higher latitudes and elevations are presumably influenced by species-specific physiological tolerances related to warming temperatures. However, it is establishment rather than dispersal that may be limiting colonizations in these cold frontier areas. In freshwater ecosystems, perennial groundwater springs provide critical winter thermal refugia in these extreme environments. By reconciling the thermal characteristics of these refugia with the minimum thermal tolerances of life stages critical for establishment, we develop a strategy to focus broad projections of northward and upward range shifts to the specific habitats that are likely for establishments. We evaluate this strategy using chum salmon (Oncorhynchus keta) and pink salmon (Oncorhynchus gorbuscha) that seem poised to colonize Arctic watersheds. Stream habitats with a minimum temperature of 4 °C during spawning and temperatures above 2 °C during egg incubation were most vulnerable to establishments by chum and pink salmon. This strategy will improve modelling forecasts of range shifts for cold freshwater habitats and focus proactive efforts to conserve both newly emerging fisheries and native species at northern and upper distributional extremes.
Keywords: Colonization, freshwater, pink salmon, chum salmon, refugia, groundwater
Annotation
Marine and terrestrial ectotherms have shifted distributions northward and upward in response to climate warming, and in fresh water, stream fishes are similarly shifting in response to warming temperatures, but at a slower pace. Development activities in Northern latitudes may need to account for potential colonization by fishes as the climate continues to warm.