Research seeks to determine if fish are linked to specific bays
COLLEGE STATION, Texas — A Texas A&M University geneticist will test whether red drum populations are genetically linked to specific bays or estuaries along the U.S. Gulf of Mexico Coast, which could possibly increase the profitability of fish farming and streamline governmental permitting processes.
Dr. John Gold, Regents Professor in the university’s Department of Wildlife and Fisheries Sciences, has received a $218,000 grant from the National Oceanic and Atmospheric Administration’s (NOAA) National Sea Grant Program Office to use recent advances in technology that should show the extent of the genetic differences between populations of red drum living in different bays and estuaries.
The two-year grant is part of the 2012 National Sea Grant Aquaculture Research Program, which funds projects that support the development of environmentally and economically sustainable ocean, coastal or Great Lakes aquaculture in states with Sea Grant Programs. The Texas Sea Grant College Program is based at Texas A&M University.
Previous technology showed there are genetic differences between red drum living along the upper and lower Texas coast and “strongly suggested that there are differences in stocks between individual bays and estuaries, but this technology was not sufficiently robust to determine this unequivocally,” Gold said. “New technology allows us to look at the red drum genome in much greater detail and answer the question as to whether there are localized genetic adaptations.”
Gold will study red drum — a popular sportfish also called “redfish” — from Texas’ various bays and estuaries as well as specimens taken from central and eastern Gulf of Mexico waters. If present, these “localized genetic adaptations” make the fish best suited to survive in the range of conditions, like salinity levels and temperature, that are common to the particular bay or estuary where the fish were born. This information would help regulatory agencies decide where new fish hatcheries should be built and where these hatcheries — be they commercial fish farms or government-run operations that provide fish for restocking programs — get their brood stock, Gold said.
Currently, the State of Texas requires that red drum hatcheries, regardless of their location, get their brood stock from Texas waters. Gold’s research may lead regulators to require that brood stock come from waters that are local to the hatcheries, which will benefit both commercial fish farms and the state’s stock enhancement operations. Both types of facilities use water from nearby sources and they should see greater survival rates by using fish that are genetically adapted to thrive in this water, Gold said. There will also be a greater survival rate among the fish released back into the local waters for stock enhancement, he said.
Increasing the survival rate in a commercial aquaculture facility will lower the cost of running the operation, he said, and “hopefully it will lower the price of redfish and make a good protein source more readily available.”
According to a report by Texas Sea Grant Aquaculture Specialist Granvil Treece for the Texas Aquaculture Association, red drum accounted for the third highest yield of commercially farm-raised finfish in the state, behind freshwater species catfish and hybrid striped bass, in 2011. About 3.25 million pounds of red drum, valued at $9 million, were produced by five facilities in Texas. There is virtually no commercial red drum aquaculture outside of Texas, Treece said.
Catfish by far accounts for the most finfish produced commercially in Texas, with 14.4 million pounds valued at about $14.4 million produced in 2011. About 3.5 million pounds of hybrid striped bass valued at $9.4 million were produced in Texas in 2011.
The Texas Parks and Wildlife Department (TPWD) currently collects red drum brood stock offshore for its stock enhancement program, says Dr. Robert Vega, TPWD’s Stock Enhancement Program Leader. Fish caught along the upper Texas coast are sent to the TPWD hatchery in Lake Jackson and those caught in the lower Texas coast region go to the hatchery in Corpus Christi. If Gold’s research confirms the connection between fish and particular estuaries, TPWD will most likely modify its stock enhancement management plan to match brood stock and hatcheries with particular estuaries and to require that juvenile fish be released into the same bodies of water that spawned their parents.
TPWD already aligns hatcheries and brood stock for spotted sea trout and southern flounder with specific estuaries, Vega says. Since the state’s stock enhancement program began in 1983, TPWD has released almost 621 million red drum fingerlings and 65 million juvenile spotted sea trout into Texas waters. About 19,000 southern flounder fingerlings have been released since its stock enhancement program began in 2006.
Texas Sea Grant is a unique partnership that unites the resources of the federal government, the State of Texas and universities across the state to create knowledge, tools, products and services that benefit the economy, the environment and the citizens of Texas. It is administered through the National Oceanic and Atmospheric Administration and is one of 33 university-based Sea Grant Programs around the country. Texas Sea Grant is a non-academic research center in the College of Geosciences at Texas A&M University. The program’s mission is to improve the understanding, wise use and stewardship of Texas coastal and marine resources.