The Crawfish Newsletter, March 27, 2020
By Mark Shirley
LSU AgCenter
Crawfish Newsletter March 27, 2020
During this Corvid 19 Virus situation, all LSU AgCenter offices are closed and Extension Agents are required to work from home (using phone and internet). We can still do limited farm visits as long as we maintain social distancing.
Crawfish Sales:
Sales of crawfish, particularly to restaurants in New Orleans, Houston and other large markets, have been interrupted. Drive thru boiling places throughout south Louisiana are moving quite a bit of crawfish but will not make up for the volume that should be going to the larger out of state markets. Processing plants will continue to put up tail meat and whole boil products as long as they can remain open, given the social distancing requirements in the work place. It is likely that a significant amount of this years crop will go unharvested.
What happens if I stop fishing and drain the pond now?
Generally, it is too early to drain the pond if you plan to fish it next season. Most ponds do not have enough mature crawfish in the field and many of the immature crawfish are not ready to burrow into the levees. Your potential harvest next year might be reduced unless you are currently overpopulated and stunted. (Male crawfish are stunted if they are small but have hooks at the base of the 2nd and 3rd pairs of waling legs. Stunted female crawfish are small and have “fatter” claws than small immature crawfish.)
What happens if I stop fishing but wait to drain?
If you stop harvesting now and wait until late April or May to drain, that will give the immature crawfish a chance to harden their shells and have a better chance of surviving until the fall flood up. This will probably give you a larger population to harvest during the winter months next season.
When should I stock new ponds for production next year?
Recently planted rice fields should wait until the rice is 10-12 inches or taller and the permanent flood is established. This will likely be sometime in May. Once the field is stocked, do not apply any insecticides. Two to three sacks per acre are usually enough to stock a rice field for crawfish production next season.
Stocking
The survival and condition of brood stock will determine the success or failure of the pond next season!
Select brood stock from healthy ponds (no signs of White Spot Syndrome Virus)
Most of the crawfish in the sack should be mature and at least 50% females
Make sure NO White River Crawfish are mixed in the sack. Don’t let those get started!
The size of the brood stock is not important. Maturity and survival are the critical factors not genetics!
Transfer the stock crawfish as soon as possible into the new pond. The longer they are out of the water and stressed, the higher the mortality.
Permanent ponds do not need to be restocked. If the pond has a problem with stunted crawfish, adding more stock may cause continued overcrowding and stunting.
White Spot Syndrome Virus
Several cases of WSSV have turned up in recent days. This is the time of the year that this virus starts to show up in some crawfish ponds. This virus only affects crustaceans (crawfish, shrimp, crabs), NOT people. The symptoms of the virus are:
Sudden and dramatic drop in catch with most of the large crawfish in the trap dead or barely moving.
Large numbers of dead floating crawfish windblown against the levee.
Please call/text/email me (337.296.6864 or mshirley@agcenter.lsu.edu ) if you think you have an outbreak of this virus. We have a team of researchers at the LSU AgCenter looking into the disease trying to figure out how it gets into a pond and why it causes such massive die offs. You can also get in touch with Dr. John Hawke at the LSU Vet School at 225.578.9705 or 225.578.9672 or by email at jhawke1@lsu.edu Directions for submitting crawfish for WSSV testing are at this web site https://filestogeaux.lsu.edu/public/download.php?FILE=mshirl2/17021wyzEWP