Each winter, recreational fishermen and biologists begin a worried watch of Texas lakes and rivers. The source of their fear: an alga that tends to expand during the colder months, sometimes with deadly results for the local fish.

Golden Algae has caused extensive fish losses throughout the major rivers of north and west Texas. In 2003 and 2005, the fresh-water organism nearly devastated some fish populations. This year, the Texas Parks and Wildlife Department (TPWD) has found growing numbers of golden algae cells in lakes including Possum Kingdom, Granbury and Whitney. Officials warn the alga may kill more fish over the next few months.

What is being done to solve this problem?
Golden algae is not just a Texas problem. The alga has killed fish in 14 other states and has been found in estuarine surface waters worldwide. It blooms under certain environmental circumstances, releasing a toxin that can kill fish and bivalves such as clams and mussels. Fish kills linked to golden algae have prompted studies worldwide. In the United States, Texas leads efforts to monitor, research, and control toxic blooms.

In 2003, the Texas Legislature authorized $1.2 million to develop tools to help the state’s aquatic managers find and battle golden alga. In 2005, the state allocated $225,000 more for the effort, receiving matching federal aid for $225,000.

TPWD created a Golden Alga Task Force to join forces with other state agencies and universities. Studies at two TPWD fish hatcheries found ways to limit alga in ponds and controlled environments. However, officials found this method could not be used in lakes or rivers because it used chemicals unsafe for other aquatic life and human drinking water.

In 2004, TPWD joined researchers at Baylor, Texas A&M, the University of Texas at Arlington and the United States Geological Survey to study the algae’s in-reservoir response several factors. The project helped officials better understand potential treatments more suitable for a reservoir system.

In 2005, the Brazos River Authority began researching another method to prevent toxic blooms. The project, funded by a $214,000 grant from the United States Environmental Protection Agency (EPA), used at Lake Granbury a method that was successful in Great Britain. Unfortunately, the approach did not decrease Lake Granbury’s golden alga population – showing no influence. This ruled out one potential for chemical-free treatment.

Though these many research programs have helped us understand golden algae, none yet have found a treatment safe for water supply reservoirs. The TPWD Golden Algae Task Force continues research and study into potential controls. For additional information on their programs, click here. For more on golden algae, click here. Small Threadfin Shad are often the first fish affected by a golden algae bloom.