TPWD Coastal Fisheries Stock Enhancement of Spotted Seatrout - Post Freeze

Stock enhancement is a fisheries management tool used around the world to help supplement wild fish populations by introducing hatchery-reared fish into the wild. The Texas Parks and Wildlife Department’s (TPWD) Coastal Fisheries Division operates three marine fish hatcheries that spawn, rear, and stock (release) Red Drum, Spotted Seatrout, and Southern Flounder fingerlings into Texas bays and estuaries. The release of hatchery-reared fish is an effective way to support and optimize a fishery. Also, supplementing wild stocks with hatchery-reared fish can help a fishery recover following mass mortality events from harmful algal blooms, freezes, or other environmental disturbances.

Back in February 2021, Winter Storm Uri had a significant impact on our natural resources. Following the six-day freeze event, Coastal Fisheries personnel conducted fish kill assessments and it was estimated that 3.8 million fish were impacted coastwide that consisted of at least 61 species. Recreationally and commercially important species made up about 9% of the total estimated fish kill. Of that 9%, the recreationally important Spotted Seatrout was impacted the most. Coastwide, 89% of the Spotted Seatrout mortality occurred in the Laguna Madre Complex (Upper and Lower combined). Due to the impact on the Spotted Seatrout populations, TPWD enacted temporary regulations by reducing the daily bag limit and slot limit for Spotted Seatrout from FM457 near Sargent south to the U.S./Mexico border. On September 1, 2023, the temporary regulations were lifted, and daily bag limits and slot limits returned to previous regulations. The rationale for the two-year temporary regulations were to allow for two natural spawning seasons to occur, allowing more fish to reproduce and speed up the recovery of the fishery.

In addition to the temporary regulation restrictions, TPWD also used another tool in their arsenal to bolster recovery of the Spotted Seatrout population, the hatchery program. Following the February 2021 freeze, the Coastal Fisheries hatchery program shifted their procedures to produce more Spotted Seatrout fingerlings. At the marine hatcheries, tank space to house broodstock is a limiting factor. To produce more Spotted Seatrout larvae, the program made the decision to reduce the number of Red Drum brooders to free up tank space for more Spotted Seatrout brooders. Another limiting factor is the number of outdoor rearing ponds to raise fingerlings. Historically, the program has had a coastwide quota for 15 million Red Drum fingerlings. To free up outdoor pond space the program reduced the coastwide quota for Red Drum from 15 million to 10 million fingerlings. This allowed us to use additional pond space to raise more Spotted Seatrout fingerlings. From the 2021 production season through the current 2023 production season, the hatchery program has released 19.3 million Spotted Seatrout fingerlings coastwide, almost doubling production numbers from the previous three production seasons combined (10.8 million fingerlings released from 2018 through 2020). Of the 19.3 million fingerlings produced from 2021 to present, 76% were stocked into the Laguna Madre Complex, as it was the most impacted by the freeze.

Through the long-term monitoring program, TPWD Coastal Fisheries Division can track the population of fisheries overtime. Figure 3 shows the gillnet catch data for Spotted Seatrout in the Laguna Madre Complex post-freeze. As of spring 2023, on average, spotted seatrout catch rates in the Laguna Madre are at or above the long-term average. Through successful management, the Spotted Seatrout fishery on the Texas coast has made a speedy recovery.

Whether we are managing an exploited fishery, supplementing a weak year class of fish, or compensating for major environmental disturbances, stock enhancement is a powerful fisheries management tool to help supplement wild populations. The TPWD Coastal Fisheries hatchery program will always be actively involved in maintaining the fisheries populations along the Texas coast. Rest assured we are doing our part to ensure great fishing for future generations of Texans to enjoy!