Influence of CO2 on fishes in flowing water environments: implications for a non-physical barrier to movement

Carbon dioxide;Fish;Behavior;Swimming performance;Invasive species;Barrier

Schneider, Eric Vaughn ; Larson, Eric R, ; ,Schooley, Robert L. ; Suski ; Cory D.

关键词: Carbon dioxide;    Fish;    Behavior;    Swimming performance;    Invasive species;    Barrier;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/98177/SCHNEIDER-THESIS-2017.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) are invasive species that have become established in the upper reaches of the Illinois River, and are nearing the connection into Lake Michigan.To prevent the spread of these carp, as well as other fish, carbon dioxide (CO2) is being investigated as a potential nonphysical barrier.However, to date, most research on the effects of CO2 on fish behavior has occurred in static water conditions.Additionally, little is known about how elevated CO2 may affect swimming performance.Here, we investigate the effects that varying levels of dissolved CO2 will have on fish behavior and swimming performance in flowing water.Chapter 1 aims to identify threshold levels of CO2 required to elicit significant behavioral responses from the native surrogate species used (bluegill, Lepomis macrochirus, and largemouth bass, Micropterus salmoides).When exposed to a range of CO2 partial pressure (pCO2; < 400 μatm [ambient], 25,000 μatm, 50,000 μatm and 100,000μatm), bluegill showed a significant increase in activity at 25,000 μatm, whereas largemouth bass activity significantly increased at 100,000 μatm.Fish were also exposed to 50,000 μatm pCO2 in five successive bursts to investigate the effects of repeated exposure to CO¬2 on fish behavior.Both species displayed a significant increase in activity during the first exposure, but then successive exposures did not change activity levels relative to baseline (at ambient pCO2).Chapter 2 aims to quantify the effects of elevated CO2 on sustained (aerobic) and burst (anaerobic) swimming performance in largemouth bass.We found that sustained swimming performance significantly decreased at 100,000 μatm pCO2 and that burst swimming was unaffected by CO2.Additionally, ~15% of fish lost equilibrium during both sustained and burst swimming tests at 50,000 μatm, and nearly 70% of fish lost equilibrium during both sustained and burst swimming tests at 100,000 μatm, showing that the rate of loss of equilibrium significantly increased as pCO2 increased.These novel findings fill a knowledge gap regarding fish behavior and performance during exposure to elevated CO2 in flowing water, and also inform the development and deployment strategies of the proposed CO2 fish barriers.