Can carbon dioxide injection control the spread of aquatic invasive species ?

What is it about?

Aquatic invasive species (AIS), such as invasive fish, can spread through waterways. There are several strategies to prevent this, which can be deployed at lock and dam structures within major rivers. Injecting carbon dioxide (CO2) into river water is one such strategy. This method deters AIS from migrating upstream and does not disrupt vessel passage or lock operation. CO2 injection systems are quite effective in small scale, controlled settings. But how do they perform in large navigation lock structures? To find out, researchers assessed the design and performance of a system deployed in the Fox River in Wisconsin.

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Photo by Sara Kurfeß on Unsplash

Photo by Sara Kurfeß on Unsplash

Why is it important?

CO2 injection in water can prevent the spread of AIS at navigation pinch points. The authors of this study assessed the performance of floor based and wall based CO2 injection manifolds in lock structures. They also studied the mixing time, mixing efficiency, injection efficiency, and power requirements for each system. Both manifolds performed well in preventing fish from entering the lock chamber or forcing resident fish downstream. Multiple concentrated manifolds met the performance requirements of locks that allow movement in one direction. Distributed manifolds performed best in locks that allow movement in both directions. These findings can help inform the effective design and operation of CO2 injection systems in the future. KEY TAKEAWAY: CO2 injection using a system of different manifolds can create a uniform CO2 field in the water. When deployed in navigation locks, this can stop the spread of invasive species. This research relates to the following Sustainable Development Goals: • SDG 14 - Life Below Water • SDG 6 - Clean Water and Sanitation • SDG 15 - Life on Land • SDG 9 - Industry, Innovation, and Infrastructure