Carol Franze and Julie Anderson Lively

The commercial blue crab industry in Louisiana lands 40 to 50 million pounds, reflecting about $50 million to $60 million annually. Soft-shell blue crab is a value-added subsection of the larger commercial crabbing industry done at shedding facilities across the coast. Shedding crabs in Louisiana dates back to the late 1800s, and production increased steadily in the 1930s and 1940s, historically producing about half a million pounds of meat annually, predominately for restaurants.

A soft-shell crab is produced by taking advantage of a crab’s life cycle. To grow larger, crabs must molt or shed their old shells. Based on a color change on the edge of the back fin, crab fishers and shedders can tell how close a crab is to molting. Peelers or busters are hard-shell crabs getting close to shedding. At shedding facilities, peelers are held in tanks until they molt. To shed the old shell, a crab swells with water and busts the old shell along the back edge of the shell. The crab then wiggles out through the back. The new shell has already formed and is about a third larger, but it is still soft. The crab will remain truly soft for a couple of hours in the water. If removed, the hardening stops. Shedders must remove soft-shell crabs quickly — at all hours of the day — to prevent shell hardening.

This value-added industry sees a six-to-seven-time increase in price over hard-shell crabs. However, since the 1990s, the number of producers in Louisiana has gone from an estimated 300 to fewer than 40 today. This loss has not always been felt across the U.S. market because, increasingly, soft-shell crab production is moving away from domestic production as more and more soft shells are imported into the United States. In 2017, only about 10,800 pounds of soft-shell were produced in Louisiana.

Although part of the loss in numbers of producers can be blamed on hurricane damage to shedding facilities often located right on the water or near the coast, shedding is a full-time, round-the-clock job that can also be a deterrent for younger fishermen. The lack of generational knowledge being handed down through family shedding facilities has resulted in a need for education of a new cohort of blue crab shedders to accommodate local demand and future industry expansion. Additionally, high mortality levels are common during this stressful life event for crabs, and while 25 percent mortality is not uncommon, 100 percent mortality is a real possibility if there is a problem in the system. Peeler crabs have been harder to get as blue crab populations have been in decline over the past few years, making higher survival rates even more important.

In 2013, LSU AgCenter agents and specialists developed workshops, a portable shedding demonstration unit, a shedding video and print materials to support the education and enhancement of crab shedders. Seven crab industry workshops have been conducted from 2013 to 2018. Each workshop is based on needs identified in the region. Topics have included crab biology, existing and new regulations, handling, shedding systems, achieving and maintaining good water quality, value-added opportunities, economics, and new research and technologies.

Historically, soft-shell crab systems were floats held off docks or on boats. Over time the industry transitioned to on-shore tank systems next to or near local waterways. These “flow-through” systems pump the local, natural habitat waters through the tanks. Good water quality is difficult to maintain in floats or flow-through systems using local waters. Large fluctuations in water temperature or salinity can cause high rates of mortality. To better maintain good water quality, a recirculating system was developed and tested in the 1980s. Today crab-shedding facilities can be located for convenience and do not have to depend on local waterways that might also be at high risk for flooding. The system’s water can be maintained at a constant temperature and salinity, and excessive nutrients or toxins can be reduced.

The crab industry workshops and demonstrations have focused on running recirculated systems in a cost-efficient manner. Additionally, handling of the crabs by fishers before they enter the shedding system can play a large role in survival. Best handling practices are encouraged for the fishers to maintain high quality in hard-shell and peeler crabs. Several naturally occurring crab diseases can cause high mortality levels in shedding systems, as well as in the wild populations. Good disease management includes not throwing diseased crabs back into the local waterways and running a recirculated system to prevent spread of disease between the wild populations and shedding facilities.

AgCenter research efforts will continue under a recently awarded grant funded through the National Oceanic and Atmospheric Association on revitalizing and increasing resilience in soft-shell crab aquaculture. Outcomes of this research will include the following: determining the cause of increased virus mortality and providing alternatives for reducing the virus within shedding facilities; increasing the number of recirculated shedding facilities adapted to the effects of coastal natural hazards; increasing the number of shedding facilities using best management practices; and increasing production of domestic, soft-shell blue crab.

Additional outreach materials are in development, and workshops and demonstrations are being planned to help our crab shedding industry survive another 100 years.

Carol Franze is a marine extension specialist in the Southeast Region, and Julie Anderson Lively is a marine fisheries specialist and an associate professor in the School of Renewable Natural Resources.

(This article appears in the fall 2018 issue of Louisiana Agriculture.)

Read: "Crab shedders persevere as Louisiana soft-shell crab industry shrinks" by Kyle Peveto

A soft-shell crab that has recently shed its shell rests in Daniel Edgar’s hands. Edgar runs a crab shedding operation as part of a seafood and marina business near Franklin. Photo by Kyle Peveto