Skip to main content

Fish behavior in elevated CO2: implications for a movement barrier in flowing water


Preventing the spread of invasive fishes is an important aspect of management programs, but is challenging due to the behavior of fish and the nature of aquatic environments. The use of dissolved carbon dioxide (CO2) has recently gained traction as a non-physical barrier for invasive fishes due to its ability to elicit avoidance behaviors in fish. Research to date has focused on the development of CO2 barriers using static water environments. Because CO2 barriers have been proposed for flowing water (i.e., in rivers or shipping canals), understanding the dynamics between fish and elevated CO2 in flowing water is essential. Our study aims to define threshold levels required to alter behavior of bluegill (Lepomis macrochirus) and largemouth bass (Micropterus salmoides) in flowing water, and to quantify behavioral metrics of fish exposed to < 200 [ambient], 25,000, 50,000, and 100,000 µatm pCO2. We also sought to quantify the impacts of repeated CO2 exposure on fish behavior. Bluegill showed increased activity at 25,000 µatm, while largemouth bass showed increased activity at 100,000 µatm. When repeatedly exposed to cycles of 50,000 µatm pCO2, bluegill exhibited increased activity followed by a diminished response after the second exposure. Results from this study define threshold levels required to elicit behavioral responses, and show that the effects that multiple exposures of elevated pCO2 can decline, possibly due to habituation. Results will help shape the development and deployment of a CO2 barrier to control the movements of invasive fishes.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5


Download references


Funding for this project was provided by the United States Geological Survey, through funds provided by the USEPA’s Great Lakes Restoration Initiative (G14AC00119). Cody Sullivan provided valuable assistance during the course of the experiment. This work conformed to protocols set through the Institutional Animal Care and Use Committee (IACUC) of the University of Illinois (Protocol #15137).

Author information

Authors and Affiliations


Corresponding author

Correspondence to Cory D. Suski.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material 1 (DOCX 251 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Schneider, E.V.C., Hasler, C.T. & Suski, C.D. Fish behavior in elevated CO2: implications for a movement barrier in flowing water. Biol Invasions 20, 1899–1911 (2018).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Carbon dioxide
  • Acidification
  • Behavior
  • Climate change
  • Barrier
  • Invasive species