Science & Nature


Friday, October 11, 2019

BREC Issues Statement Regarding Small Fish Kill at City Park Lake

With temperatures remaining above forecasted levels, the BREC Natural Resource Management and maintenance teams are coordinating efforts to respond to a small fish kill in City Park Lake.

As previously reported, City Park Lake is currently experiencing algae blooms, shallow water and high temperatures. These conditions are the result of a shallow lake and high nutrient loads via stormwater inlets. As anticipated, these conditions have resulted in a small number of fish dying within the pond. Under these conditions fish die as a result of a lack of dissolved oxygen in the water due to several factors.

The lake includes a sensitive balance of vegetation communities, insects, bacteria, fish and other fauna. Because the lake is so shallow and the water so warm, it is not able to hold a lot of dissolved oxygen which fish need to survive. Most of the oxygen in a pond is created by the photosynthesizing vegetation under the water, using sunlight to generate oxygen. At night when the sun goes down and when it is cloudy, the vegetation does not generate as much oxygen, which can result in fish death. The algae blooms only compound this issue by reducing habitat and shading out the plants below the surface of the water. As algae goes through its life cycle and dies, and as the shaded plants below algae die, the bacteria decomposing them consumes oxygen, further decreasing dissolved oxygen and stressing fish.

BREC continues to monitor the conditions of the lake and anticipates that if warm conditions continue, there will be more fish kills. Fish kills are not a new problem at the lake, and they have been recorded in both lakes consistently since 1948. That being said, BREC is dedicated to bringing City Park Lake back to health and addressing the root of the problem by increasing the depth and filtering out unnecessary nutrients.

“We realize that utilizing carp or introducing a chemical solution is a short-term solution as the imbalance in the lake is caused by a combination of lack of depth and heat,” said BREC Superintendent Corey K. Wilson. “As we have said, BREC is committed to dredging the lake and we are working with numerous other agencies to pool funds to ensure that the entire system of lakes will be dredged. This will not only ensure the health of the lakes but will allow the master plan created by the Baton Rouge Area Foundation to become a reality showcasing the preeminent recreational amenity in our area. I am confident that this project can begin as soon as the fourth quarter of next year following the months of planning that will be required to successfully complete the work,” said Wilson.

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