Study Tests Feasibility of Design and Operation of Carbon Dioxide as a Behavioral Deterrent

Currently, prevention of the movement of Asian carp from the Mississippi watershed into the Great Lakes rests on several electric barriers located in the Chicago Area Waterway System (CAWS).  Additional barriers and/or supplements to the electric barriers would improve the efficacy of deterring Asian carp movement into the Great Lakes through redundancy and ‘safety nets’, and offer greater confidence in their containment.  For example, development of a chemical barrier that generated noxious water conditions might repel Asian carp and prevent them from passing upstream through navigational locks. One candidate barrier chemical that has received a great deal of attention has been carbon dioxide gas (C02). Several studies have demonstrated that Asian carps and other non-native fishes can sense and will avoid areas infused with C02. Managers could capitalize on this avoidance response to repel carps and reduce the risk of upstream passage. Carbon dioxide does not appear to be species or size specific, which suggests that C02 may act as a non-physical barrier to deter fishes from entering new areas. A large-scale C02 infusion system has been designed for installation and operation within navigational locks.

The U.S. Geological Survey (USGS), U.S. Army Corps of Engineers (USACE) and partners are evaluating the use of carbon dioxide (C02) as a behavioral deterrent to block Asian carp migration  through navigational locks. The concept is to introduce C02 into lock chamber water during upstream vessel lockages to remove fish from the lock chamber and thereby reduce the risk of upstream fish passage. Concentrations being targeted for this use pattern are not expected to be lethal to aquatic organisms. Rather, C02 will be infused at sub-lethal levels to temporarily saturate the lock chamber water during lockage events with C02 to push fish downstream. Several published studies have demonstrated avoidance behaviors from Asian carps and other invasive fishes in controlled environments and the next step is to evaluate the feasibility this new fish deterrent method at relevant management scales.

The USGS received approval from the Fox River Navigational  System Authority (FRNSA) on August 28, 2018 to conduct a feasibility study at Kaukauna Lock 2 in 2019. The proposed study is strictly for research purposes and has no affiliation with management actions at Kaukauna Lock 2 or the Fox River system in general. Kaukauna Lock 2 was selected as an ideal test site because there is no public access and FRNSA locks in Kaukauna are not being operated for public use in 2019. Researchers will have full control over the test site. The purpose of this feasibility study is to design, construct, operate, and collect data on a C02 fish barrier to inform installation at other key Asian carp management locations (e.g., Brandon Road Lock and Dam near Joliet, IL).

Who was leading the study? What were the objectives?

Scientist monitors C02 levels during Asian carp barrier field trials on the Illinois River

The USGS conducted this feasibility study by infusing C02 into the lock chamber water twice per day (Monday-Friday) for 4 weeks. The overall goal of this project was to determine the feasibility of C02 as a fish barrier at navigational locks. A team of researchers from USGS Upper Midwest Environmental Sciences Center, USGS Upper Midwest Water Science Center (UMWSC),

USGS Central Midwest Water Science Center (CMWSC), USGS Western Fisheries Research Center, USACE Engineering Research and Development Center, U.S. Fish and Wildlife Service Midwest Fisheries Center, U.S. Coast Guard Research and Development Center, University of Wisconsin Platteville, and University of Illinois identified five data objectives for this study to inform management and regulatory agencies on the long-term use of C02 for invasive fish control:

  1. Engineering and economic assessment – determine the efficiency and operational costs associated a C02 infusion system
  2. Water quality – quantify C02 dispersal within and outside of the treatment area (lock chamber)
  3. Air quality – determine any potential human health risk assessments of a CO2 system
  4. Fish behavior – quantify behavioral responses of introduced fish (rough fish already in the Fox River) during C02 treatments
  5. Non-target toxicity – evaluate any potential impacts to native species, particularly macroinvertebrates such as native mussels

Results of the study will be published on a future date. Now that the 4 week test has been completed, the C02 infusion system will be removed from the Lock.

The information above is originally from the United States Geological Survey (USGS).

Photo Credit: USGS, Fox River Navigational System Authority

Questions? Comments? Contact Chris Acy, the AIS Coordinator for the Winnebago Waterways Program covering Fond du Lac, Calumet, and Winnebago Counties at (920) 460-3674 or chris@fwwa.org!