Crawfish producers keep eye on pond oxygen
Mar 7, 2008 9:47 AM, From the LSU AgCenter
Most crawfish producers don’t check oxygen levels of their water, but that step can help improve production, according to an LSU AgCenter aquaculture expert.
“If you’re in the crawfish business, you really ought to be checking it on a regular basis,” Robert Romaire told producers at Hamburg, La., meeting. The meeting was one of several conducted by the LSU AgCenter throughout the crawfish-growing region.
Romaire said oxygen levels tend to increase during colder months, but the levels are low after a pond is flooded in the fall and when temperatures begin to increase in late spring.
Low oxygen can lead to stressed crawfish, exposing them to diseases and slow growth. Kits to test water for oxygen cost less than $50.
Greg Lutz, LSU AgCenter aquaculture specialist, said allowing the water to spill over screens as it flows into a pond should oxygenate water pumped from the ground. Good oxygen levels will take care of the bad effects of high levels of iron and hydrogen sulfide, he said.
Romaire said crawfish producers often ask if they should feed crawfish with hay or other material. “By and large, it doesn’t pay. It’s usually a waste of time, money and effort.”
The population density of crawfish determines their size and growth rate. A large population results in smaller crawfish that won’t grow quickly because they are competing for food.
Romaire said it’s not recommended that small crawfish be returned to the water because they either won’t survive or won’t grow.
Producers are asking why this year has been difficult with late crawfish that are small. Romaire said many producers waited for rainfall to avoid the expense of pumping, and flooding didn’t occur until November, which delayed emergence of female crawfish with young.
It usually takes three to four months for a pond to produce harvestable-sized crawfish. If a pond is flooded in September a producer shouldn’t expect to have marketable crawfish until December.
Romaire also advised running traps three or four days per week and every other day for large crawfish.
Following the meeting, crawfish producers said their catches have been improving. “It’s looking good for us,” said Ed Laborde of Hessmer, La.
Allen Wyman of Simmesport, La., said the 5-acre pond he manages has been producing close to 200 pounds a day. “They’re a decent size,” he said.
Roland Dugas, who farms near Spring Bayou, La., said he will start harvesting after March 1. Until then, he said, it’s not profitable. Dugas’ best crawfish months are May and June.
Robert Devillier of Plaucheville, La., is in his first year of production. “At first it was very slow. Everybody is running behind.”
