This is the fourth in a series of posts about “The Fish Kill of 2009.”

Fish kills in impoundments around South Carolina are a common occurrence.  In the heat of the summer, especially in August, the dissolved oxygen in the water gets low, making it hard for fish to breathe.  As sensitive fish like menhaden start to die, the decaying process uses oxygen from the water, making it harder for everything else in the area to stay alive.  This can cause fish kills to have a “snowball” effect.  The problem accelerates with each death.

Dewees has had several fish kills.  When a fish kill gets out of control, it can dessimate the fish population in the impoundment.  In years past, the staff has had to use backhoes to get the dead fish out of the impoundment and then bury them.  Dewees works hard to avoid fish kills.

Dewees does a number of things to try to avert fish kills, including monitoring the level of dissolved oxygen at several places in the impoundment and flushing the impoundment occassionally to get new oxygenated water into the impoundment.  The island also has two aerators in the impoundment — one out in the middle of the impoundment and one in Chapel Pond.  The island has a written management plan for the impoundment and it’s followed closely.