FishKillANaturalEvent

This story is from the Desoto Times

(DeSoto Times photos by Curt Middleton)

A line of geese swim past belly up dead fish on a lake in the Maywood subdivision in Olive Branch Friday. Scientists from the Mississippi Department of Environmental Quality determined the fish kill was the result of oxygen depletion caused by the recent lack of rain, high temperature and extensive algae bloom in the water.

Olive Branch 'fish kill' a natural event

By CURT_MIDDLETON/Editor (Updated: Saturday, August 11, 2007 10:34 AM CDT)

OLIVE_BRANCH - Stephen Crowdus has lived by his lake in the Maywood subdivision in Olive Branch all his life. Crowdus, 62, said he only had seen this scene once before - some 30 years ago.

The lake behind his home on Sylvan Lane was a great fishing "hole," according to Crowdus. He spoke in the past tense waving his arm at the scene of thousands of fish floating belly up behind his home.

"Isn't that smell something?"

Crowdus' daughter, Leslie Jobe, lives next door to her dad. She said the family noticed fish going belly up Tuesday and it became worse Thursday.

After a conversation with Olive Branch Mayor Sam Rikard, Jobe called the Mississippi Department of Environmental Quality (MDEQ) asking for help.

Randy Jones, an environmental scientist, along with Dewitt Spurgeon, an environmental specialist, arrived Friday afternoon from their base in Oxford, responding to Jobe's request.

After making initial examinations of the lake while noting conditions, Jones said he was certain what caused the fish kill. He said it was oxygen depletion.

Oxygen depletion occurs, Jones said, when consumption exceeds production. He said the sure-fire indication was the pea-soup green water color. This, he said, indicated an extensive presence of algae that consumed all available dissolved oxygen (DO), a gas dissolved in water and absorbed by fish into their bloodstream through their gills.

"Recent conditions and the lake's situation make it a perfect time for this to happen," Jones said. "The lake water level is more than two feet below normal and, unlike the other lakes, has little wind churning up the water. Plus, a lack of rainfall plus excessive sunlight and heat help to create this situation." He said without some type of natural aerating, the heat and algae growth in the water led to the oxygen depletion causing the massive fish kill.

According to MDEQ, warm water is much less capable of holding oxygen gas in solution than cool water. For example, water that is 90¡ F can only hold 7.4 mg/L DO at saturation, whereas water that is 45¡ F can hold 11.9 mg/L DO at saturation. This physical phenomenon puts the fish in double jeopardy because at high water temperatures their metabolic rates increase, hence their physiologic demand for oxygen increases. And, although plant life in and around the lake contribute to the healthy amount of DO needed to sustain fish, an overactive consumption of DO will lead to a fish kill.

Jones said that his department could do nothing to help since it was a private lake. He did say that the homeowner's association might consider the use of pond aerators to prevent this from happening again. As for the strong stench produced by the dead fish, he said nature would have to play clean-up hitter. In time with birds and other fowl feeding, plus fish eventually sinking to the bottom, the smell will go away.

"This is such an awful shame," Jobe said. She said she has to change plans for a party/reception for some friends who were going to be married.

Curt Middleton can be contacted at cmiddleton@desototimes.com or (662) 429-NEWS, Ext. 247.

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FishKillANaturalEvent

Olive Branch 'fish kill' a natural event