LSU AgCenter and Sea Grant crawfish specialist Mark Shirley said straw and vegetation in the fields that have been flooded would deteriorate, depleting oxygen in the hot water.
Fields that become flooded from rain should be flushed to move bad water off the fields.
“Right now, those crawfish are safer down in the burrows for at least another three to four weeks,” Shirley said.
Crawfish burrowed now will be caught early in the season, and their young will be ready for the main crop.
Levee-building can kill crawfish by damaging their burrows, he said. But many farmers pull levees annually, and they still have a good crop.
Crawfish need oxygen levels of about 2 to 4 parts per million, and oxygen can be introduced to water by using splash screens.
Small crawfish caught in traps should not be returned to a pond because it’s unlikely they will grow enough to be the desired size, Shirley said.
Research is being conducted at the LSU AgCenter H. Rouse Caffey Rice Research Station near Crowley to study the effects of harvesting crawfish on a rice field that has been second cropped. Two rice fields are being used.
One will be managed for crawfish after the main rice crop, and another field where a second rice crop will be grown will be followed by crawfish production.
Both fields will be monitored closely for water oxygen levels and temperature, as well as harvest amounts.
Jimmy Meaux, AgCenter agent in Cameron and Jefferson Davis parishes, said crawfish on fields used for a ratoon rice crop is becoming more popular. “We’ve been getting a lot more calls about that,” he said.
Last year’s crawfish season was affected by cloudy weather that made the crop late. The catch didn’t improve until April or May, about two months behind the usual schedule, Shirley said.
The lack of weather changes likely delayed crawfish growth and development.
“We probably missed two or three molts in the wintertime,” he said.
Crawfish farmers can make a profit eight to nine years out of 10 if they manage their fields properly, Shirley said, and a haphazard approach will result in a profit about three out of 10 years.
Farmers face challenges
White spot virus is becoming more of a problem. The disease started showing up in 2007, he said.
It appears to only affect larger crawfish.
Louisiana Sea Grant has approved funding for a study of the disease, and sampling will be done in all areas of the state with crawfish production.
Apple snails, an invasive species, have become a problem for some crawfish operations by getting in the traps and clogging the entrances. A study is being conducted to find out control methods for the pest, Shirley said.
Statewide crawfish acreage last year totaled about 240,000, and he expects that to increase. “I think we’ll make a quarter million acres this season,” he said.
Whole-boiled frozen crawfish is becoming more widespread, and the quality is good. Shirley said the preparation technique is helping the industry by providing an additional way of selling the product.
Samantha Carroll, executive director of the Louisiana Seafood Promotion Board, said she and her husband toured China last year. They went to a street in Beijing with restaurants that exclusively sold crawfish, and one of their main dishes was crawfish that had been boiled and frozen.
Also at the meeting, Sara Zimorski, of the Louisiana Department of Wildlife and Fisheries, said whooping cranes are often found in crawfish fields. She said 47 of the 74 cranes’ nests have been found in crawfish ponds, and 81% of the hatchings have occurred in crawfish ponds.
But Zimorski said the cranes’ presence will not restrict farmers from conducting their usual agricultural practices.
“You can go about doing things you normally do even though there are cranes on your property,” she said.
Additional crawfish meetings are planned for:
• Oct. 1 at 6 p.m. in the Evangeline Parish AgCenter Extension office at 230 Court St. in Ville Platte.
• Oct. 2 at 6 p.m. in the Vermilion Parish AgCenter Extension office at 1105 W. Port St. in Abbeville.
• Oct. 3 at 1 p.m. in the Lafourche Parish AgCenter Extension office at 115 Texas St. in Raceland.
Louisiana State University AgCenter contributed this article.