Commission Agenda Item No. 13
Presenter: Shane Bonnot

Southern Flounder Stock Enhancement
January 22, 2015

I. Executive Summary:  Staff will brief the Commission regarding the status of southern flounder production for purposes of stock enhancement at three Coastal Fisheries Division hatcheries.

II. Discussion: Since 2006, efforts to develop aquaculture technology for production of southern flounder (Paralichthys lethostigma) using pond culture systems have been carried out by the Coastal Fisheries Division’s hatcheries.  Southern flounder, declining in much of its range, is considered a viable candidate for stock enhancement and aquaculture.  As urbanization of Texas’ coastal areas continues, fishing regulations, law enforcement, long-term independent fisheries monitoring, habitat restoration and other fisheries management tools may all be used to support and sustain fish populations. Stock enhancement (stocking hatchery-reared fish into the wild) provides one tool for addressing increased fishing pressure and declining stocks. The objectives of the southern flounder stocking program are to develop methods to culture juvenile flounder on a large-scale hatchery basis for purposes of stock enhancement.

Efforts to culture southern flounder on a large-scale hatchery basis have been hampered by limited information regarding captive broodfish spawning, and larval stage grow-out procedures. Currently, most methods used to culture southern flounder have been designed for small laboratory-scale production. The challenge for Coastal hatcheries staff has been to expand upon current technology and develop cutting-edge methods for the large-scale production of high quality juvenile flounder.

To-date, a total of 184,208 juvenile southern flounder have been stocked into Texas coastal waters (Galveston Bay, Sabine Lake, and Aransas Bay). Advances have been made in spawning and larviculture methods, biological/genetic studies, and ability to retrofit and transition hatchery systems from red drum and spotted seatrout culture from March – November to flounder culture (November – March).  Other areas of research being conducted by Coastal staff and university collaborators include the development of bay stocking strategies (optimal fish size, release habitat, magnitude of releases, and contribution assessment).

The Coastal Fisheries Division has placed a major emphasis to develop and implement effective and responsible southern flounder stock enhancement technology.  A multidisciplinary approach is being used to integrate stocking with traditional fishery management practices in an effort to improve the health of the southern flounder population in Texas.