News Column: COASTAL CURRENTS
Submitted: April 10, 2013
Alan Matherne, Coastal & Fisheries Outreach Specialist
Terrebonne, Lafourche, and Assumption Parishes; LSU AgCenter/Sea Grant
Setting Louisiana’s shrimp seasons
Ever wonder how they set the opening date for our spring inshore brown shrimp season? If so . . . read on.
Louisiana’s shrimp fishery consists of primarily two species: the brown shrimp (Farfantepenaeus aztecus) and the white shrimp (Litopenaeus setiferus). The shrimp fishery is Louisiana’s most valuable commercial fishery with an average of more than 8,700 licensed shrimpers each year. According to the National Marine Fisheries Service (NMFS), in 2011 (the latest year for which complete data are available) over 92 million pounds of shrimp were landed in Louisiana with a dockside value of just over $133 million.
Louisiana’s shrimp industry started over a century ago with a handful of fishermen using haul seines and cast nets. Trawling began at first with wooden sailboats in the mid-1800s. This led, in the early 1900s, to the use of Model T and Model A engine powered wooden luggers.
By the 1980s, shrimp trawling gear and vessels had become substantially more sophisticated with the use of advanced multi-rig otter trawl designs and butterfly nets aboard vessels ranging from twin-diesel steel-hull “super slabs” to high-powered fiberglass skiffs.
Finally, the 1990s brought us more advancements in trawling effort with various double-rig setups for inside waters and the even more recent development of “skimmer rigs” or, more simply, “skimmers.”
What was once an industry supporting just a few fishermen using relatively simple gear has evolved into a highly competitive commercial and recreational enterprise engaged in by many thousands of people utilizing the latest in sophisticated gear, equipment, and vessels.
As a consequence, the necessity for more rules and regulations governing the management of Louisiana’s shrimp fishery has also evolved into the many and complex shrimp laws found in today’s law books.
In the early ’60s, recognizing the need for a more flexible spring shrimp season, fishermen and fisheries managers got together and came up with the management criteria that are currently being used to set the spring inshore brown shrimp season.
This measure calls for opening the season when it is predicted that at least 50 percent of the shrimp in inshore waters will reach 100 count per pound. One hundred count shrimp are considered the minimum marketable size.
From the mid-1960s through the 1970s, the Louisiana Department of Wildlife and Fisheries (LDWF) was able to show that brown shrimp growth and survival is directly related to water (hydrologic) conditions found in inshore coastal marsh and water areas (nursery grounds) during the spring months, with April being the most critical month. The most important hydrologic conditions (parameters) are salinity and temperature, with higher salinities and temperatures associated with better shrimp growth and survival.
Biologists continuously take samples at hundreds of locations throughout coastal Louisiana. In addition to monitoring hydrologic conditions of the nursery grounds, biologists watch shrimp growth by sampling the shrimp from the time they enter the estuaries as small 1/2 inch post larvae until shrimp leave the inshore waters as larger, harvestable adults and subadults.
In order to be able to manage shrimp on a regional rather than statewide basis, the Wildlife and Fisheries Commission (WFC) in 1975 divided the state into three shrimp management zones. Accordingly, “Zone 1 extends from the Louisiana/Mississippi state line to the eastern shore of South Pass of the Mississippi River. Zone 2 extends from the eastern shore of South Pass of the Mississippi River to the western shore of Vermilion Bay and Southwest Pass at Marsh Island. Zone 3 extends from the western shore of Vermilion Bay and Southwest Pass at Marsh Island to the Louisiana/Texas state line.”
The WFC is required by law, R.S.56:497A(7), to “. . . fix no less than two open seasons each calendar year for all inside waters by zone, based upon biological and technical data which indicates that marketable shrimp, in sufficient quantities, are available for harvest.”
They are also required to hold a public hearing prior to the opening of a shrimp season, and at that meeting to present biological and technical data concerning the shrimp season, and to set an opening date for the season based primarily upon the data presented. The WFC also takes public testimony from interested citizens relative to the opening of the spring inshore brown shrimp season.
This year’s public shrimp hearing will be conducted at the Wildlife and Fisheries Commission’s meeting to be held sometime around late April or early May. At that meeting, biologists from the LDWF will present biological and technical information used to predict the percentage of shrimp in inside waters at the 100 count level at certain dates.
This generally leads to opening dates for the spring inshore season of sometime in early to mid-May. The season then normally runs through June and ends sometime in July. Different zones may have different opening/closing dates depending upon the biological and technical data and public input.
Last year, the earliest opening was on May 7 in Zone 2. The other two zones opened on May 21. As for when this year’s spring inshore brown shrimp season will begin . . . we’ll just have to wait and see.
From the Louisiana Sea Grant Newsroom …
Cast Net Making Classes Offered
GRAND ISLE – Louisiana Sea Grant’s Marine Education Program is hosting cast net making classes beginning Thursday, May 9, and continuing every Thursday for 12 weeks from 6:00 p.m. to sunset.
The classes will be held at LSG’s Oyster Hatchery Operations Center located at 135 Port Drive, Grand Isle, and are open to everyone. Registration is $50 and includes all materials needed to make a net. Registration is free for students in grades K-12. John Supan, director of Louisiana Sea Grant’s oyster hatchery, will conduct the classes. Evening commentary will be provided by Grand Isle native Ambrose Besson.
To register or for more information, contact Supan at 985-264-3239 or email email@example.com.
Alan Matherne is the LSU AgCenter / Louisiana Sea Grant Coastal & Fisheries Outreach Specialist for Terrebonne, Lafourche, and Assumption parishes. He can be contacted at 985-873-6495 or firstname.lastname@example.org. His articles and blogs are posted at bayoulog.com. You can “Friend” him on Facebook at facebook.com/alan.matherne and follow his “Tweets” on Twitter at twitter.com/amatherne.
Louisiana Department of Wildlife and Fisheries
* Commercial Shrimping
* Recreational Shrimping
* Shrimp Season Set Next Week in Portion Of Louisiana Offshore Territorial Waters (Release: Apr 10, 2013)
Louisiana Sea Grant
* A Shrimp’s Niche In Its Ecosystem
* Anatomy of a Shrimp
* Life Cycle of a Shrimp
* Fisheries Home
* Commercial Fisheries Statistics
* Office of Science and Technology
* Southeast Fisheries Science Center
* Fisheries Economics of The U.S. 2011
* Fisheries Economics of The U.S. 2011: Gulf of Mexico
* FB13-011 – February 20, 2013 – Fishermen Are Reminded of the Importance of Complying With All TED Regulations Under New Fleet-wide TED Performance Standard for Shrimp Otter Trawls
* FB13-010 – February 20, 2013 – NOAA Fisheries Reminds Shrimp Fishermen of Tow Time Restrictions on Skimmer, Pusher-head, and Wing-Net Trawls in Lieu of TEDs