The complimentary role of lentic and lotic habitats for Arctic grayling in a complex stream-lake network in Arctic Alaska

Ecology of Freshwater Fish
By: , and 

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Abstract

Lakes can be important to stream dwelling fishes, yet how individuals exploit habitat heterogeneity across complex stream-lake networks is poorly understood. Furthermore, despite growing awareness that intermittent streams are widely used by fish, studies documenting use of seasonally accessible lakes remain scarce. We studied Arctic grayling (Thymallus arcticus) in a small seasonally flowing (June – October) stream-lake network in Alaska using PIT telemetry. Overall, 70% of fish visited two lakes, 8% used a single lake, and 22% used only stream reaches. We identified four distinct behavioral patterns that differed in dominant macrohabitat used (deep-lake, shallow-lake, or stream reaches), entry-day into the network, and mobility. Some juvenile fish spent the entire summer in a shallow seasonally frozen lake (average 71 days), whereas others demonstrated prospecting behavior and only entered the stream channel briefly in September. Another group included adult and juvenile fish that were highly mobile, moving up to 27 km while in the 3-km stream-lake network, and used stream reaches extensively (average 59 days). Lentic and lotic habitats served differing roles for individuals, some fish occupied stream reaches as summer foraging habitat and other individuals used them as migration corridors to access lakes. Our study emphasizes the importance of considering stream-lake connectivity in stream fish assessments, even to shallow seasonally frozen habitats not widely recognized as important. Furthermore, we demonstrate that individuals may use temporary aquatic habitats in complex and changing ways across ontogeny that are not captured by typical classifications of fish movement behavior.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The complimentary role of lentic and lotic habitats for Arctic grayling in a complex stream-lake network in Arctic Alaska
Series title Ecology of Freshwater Fish
DOI 10.1111/eff.12444
Volume 28
Issue 2
Year Published 2019
Language English
Publisher Wiley
Contributing office(s) Coop Res Unit Seattle
Description 13 p.
First page 209
Last page 221
Country United States
State Alaska