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Effect of water temperature on activity of wintering age‐0 Acipenser transmontanus and A. brevirostrum: An artificial stream study

Effect of water temperature on activity of wintering age‐0 Acipenser transmontanus and A.... The effect of water temperature on behaviour and life history of wintering age‐0 = young‐of‐the‐year (YOY) northern sturgeons (populations using winter refuge habitat) is poorly understood. Using artificial stream tanks, we observed the effect of water temperature on 1) day‐time activity of cultured YOY Kootenai River white sturgeon, Acipenser transmontanus, during two winters (2008 and 2009–2010), and 2) observed day‐time activity of cultured YOY Connecticut River shortnose sturgeon, A. brevirostrum, in the winter, 2009–2010. Activity of YOY was measured every 2 to 7 days by visual or video observations on each fish to determine the mean number of 10 cm2 square gridlines on the tank bottom crossed by all fish in each replicate tank (two replicate tanks, 10 fish in each tank). Daily water temperature was recorded by a logger in one tank every 20 min, 24 hr per day. In 2008, YOY A. transmontanus activity was positively related to decreasing mean daily temperature (R2 = 0.96, p < 0.01) with 0 to 5 gridlines (range) crossed by all fish during observation periods at the coldest temperature (≤3°C). During the winter of 2009–2010, activity of both species was significantly related to decreasing temperature, and again, a mean of 0 to 5 gridlines (range) were crossed by fish at ≤3°C. We accept the hypothesis that YOY of both species are mostly inactive in the day when winter water temperature decreases to ≤3°C. Using the daytime inactivity temperature threshold of 3°C for YOY, and recent temperatures in river reaches where wild wintering YOY likely occur, we predict (a) wild wintering YOY A. transmontanus are moderately active in the day, may be energy challenged due to elevated temperatures from the warm river discharge by Libby Dam, and have poor survival in the regulated Kootenay River, and (b) wintering YOY Connecticut River A. brevirostrum are moderately active most winter months due to elevated natural river temperatures and may be energy challenged. More research is needed on YOY wintering activity and energetics relative to temperature to insure management of river temperature includes conservation of sturgeons. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Applied Ichthyology Wiley

Effect of water temperature on activity of wintering age‐0 Acipenser transmontanus and A. brevirostrum: An artificial stream study

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References (14)

Publisher
Wiley
Copyright
"Copyright © 2019 Blackwell Verlag GmbH"
ISSN
0175-8659
eISSN
1439-0426
DOI
10.1111/jai.13838
Publisher site
See Article on Publisher Site

Abstract

The effect of water temperature on behaviour and life history of wintering age‐0 = young‐of‐the‐year (YOY) northern sturgeons (populations using winter refuge habitat) is poorly understood. Using artificial stream tanks, we observed the effect of water temperature on 1) day‐time activity of cultured YOY Kootenai River white sturgeon, Acipenser transmontanus, during two winters (2008 and 2009–2010), and 2) observed day‐time activity of cultured YOY Connecticut River shortnose sturgeon, A. brevirostrum, in the winter, 2009–2010. Activity of YOY was measured every 2 to 7 days by visual or video observations on each fish to determine the mean number of 10 cm2 square gridlines on the tank bottom crossed by all fish in each replicate tank (two replicate tanks, 10 fish in each tank). Daily water temperature was recorded by a logger in one tank every 20 min, 24 hr per day. In 2008, YOY A. transmontanus activity was positively related to decreasing mean daily temperature (R2 = 0.96, p < 0.01) with 0 to 5 gridlines (range) crossed by all fish during observation periods at the coldest temperature (≤3°C). During the winter of 2009–2010, activity of both species was significantly related to decreasing temperature, and again, a mean of 0 to 5 gridlines (range) were crossed by fish at ≤3°C. We accept the hypothesis that YOY of both species are mostly inactive in the day when winter water temperature decreases to ≤3°C. Using the daytime inactivity temperature threshold of 3°C for YOY, and recent temperatures in river reaches where wild wintering YOY likely occur, we predict (a) wild wintering YOY A. transmontanus are moderately active in the day, may be energy challenged due to elevated temperatures from the warm river discharge by Libby Dam, and have poor survival in the regulated Kootenay River, and (b) wintering YOY Connecticut River A. brevirostrum are moderately active most winter months due to elevated natural river temperatures and may be energy challenged. More research is needed on YOY wintering activity and energetics relative to temperature to insure management of river temperature includes conservation of sturgeons.

Journal

Journal of Applied Ichthyology – Wiley

Published: Feb 1, 2019

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