Catfish growers, pond owners warned of heat impact

MISSISSIPPI - Warm water holds less oxygen for fish than cooler water, the Mississippi Extension Service warns. Fish kills can occur when too little oxygen is available for the fish.

As oxygen levels drop, fish may be seen swimming close to the pond surface at sunrise, appearing to gasp for air, said Jimmy Avery, professor and aquaculture leader at the Thad Cochran National Warmwater Aquaculture Center in Stoneville.

Pond managers can improve oxygen in small ponds by using surface-spraying aerators, Avery said. It is usually difficult, however, to increase oxygen levels in ponds larger than 2 or 3 acres.

"Spraying pond water into the air exposes water droplets to oxygen," Avery said.

"To increase oxygen levels enough to make a real difference, it is important to break the water droplets into a fine mist and expose the mist to the air."

Source: The Clarion-Ledger