Crawfish farmers keep an eye out for disease
JENNINGS — Crawfish farmers in Southwest Louisiana are keeping an eye on this year’s crawfish production as the deadly white spot syndrome virus continues to threaten to decrease crawfish production 10 years after it was first detected.
LSU AgCenter aquaculture specialist Mark Shirley said the disease has been confirmed in seven crawfish ponds in south Louisiana and the Atchafalaya Basin, including Jeff Davis, Vermilion and Acadia parishes, this year. It was first found in 13 parishes in 2007 after being detected in a well-water pond in Arnaudville.
“How would a virus that was a crustacean virus found in shrimp farms around the world get to Arnaudville, La., or Jeff Davis Parish for that matter, we don’t know,” Shirley said.
Shirley and aquatic animal health specialist John Hawke met with nearly 40 crawfish farmers Tuesday to get input and see how many might be experiencing problems, including a drastic reduction in harvest.
The virus is also found in crabs, shrimp and other crustaceans, but is not a threat to humans.
“It is not an issue as far as eating crawfish,” Shirley said. “It’s not getting in the food chain of people because dead ones are not going to market.”
Donnie Bruchhaus said crawfish tissue samples tested from his 142-acre pond in Elton tested positive for the virus in early April. He has since ceased production.
“I drained the pond after my production went to zero,” Bruchhaus said, shaking his head. “That was a big hit.”
He plans to grow rice in the field next year.
Stephen Berken, who farms crawfish in two ponds in southwest Jeff Davis Parish, suspects the virus has affected production in his 75-acre pond the last two years.
“We went from catching really nice crawfish and a lot of them to down to zero within five to seven days, both years,” Berken said. “Now there’s nothing left to catch. All that’s left is little, very small immature crawfish.”
Berken is now moving his crawfish fields and plans to restock them with what he hopes to be healthy seed crawfish.
Allen Ardoin has also seen a significant loss of crawfish in his 250-acre pond south of Welsh this year, but is not sure of the cause.
“I went from 45 to 50 sacks of crawfish to eight to 25 sacks a day, and every day it has been getting less,” Ardoin said. “I’m now down to about a dozen sacks a day. I’ve never had this problem before.”
Shirley said the virus seems to affect mostly medium to large crawfish. Affected crawfish are lethargic, uncoordinated, unable to right themselves if laid on their side and cannot let go once they pinch with their claws.
Most of the dead crawfish are noticeable in the traps, while others are noticeable along the edge of the pond in the shallow water, Shirley said.
The virus is confirmed by a special test, called PCR, which detects the DNA of the virus. The test costs $35 and can be conducted by the Louisiana Animal Disease Diagnostic Laboratory at the LSU vet school.
“It’s a virus, so there’s really no drug that you can treat it with,” Hawke said. “All you can do is try to find ways to manage it. We need some really good documentation and more research to be able to find out more.”
Crawfish in Louisiana. (Edyta Blaszczyk/Odessa American via The Associated Press)