Study Identifies Variables That Contribute to High Golden Algae Blooms; Awarded New Grant
Baylor University researchers have identified several components that contribute to toxic levels of golden algae, which kill millions of fish in Texas every year. While golden algae is primarily a coastal species, it has been found in rivers and lakes all over the state, including Lake Whitney and Lake Waco in Central Texas.
Experts know the saline content of the water contributes to the large golden algae blooms, but new research from Baylor scientists shows there are several additional environmental and biological factors that play a critical role in the algae's toxicity.
Dr. Bryan Brooks, an associate professor of environmental science and biomedical studies at Baylor, and researchers from Texas A&M University and the University of Texas at Arlington, have observed that temperature and the ratio of nutrients strongly impacts whether the golden algae actually blooms. The researchers found that if the ratio of nitrogen and phosphorus gets out of balance, the toxicity of the golden algae changes and its ability to grow is affected.
The researchers also discovered that climate variability plays a role with warmer water temperatures increasing the likelihood of large algae blooms in laboratory experiments, but this was not observed in some area lakes like Lake Waco. Researchers believe other algae that bloom during the summer months might inhibit the growth of golden algae.
"Golden algae is aggressive and very unique because it can produce its own toxin, swim, photosynthesize and feed on other organisms," Brooks said. "If we can figure out different concentrations of nutrients that can stimulate the growth of other algae, we might be able to hinder the growth of golden algae. It would be a biological control method."
To understand the competition between golden algae and other algae, the researchers have received a $498,000 grant from the Texas Parks and Wildlife Department for a comparative study of Lake Waco and Lake Granbury near Dallas. The researchers will try to locate certain coves or "hotspots" in the lakes where conditions are optimal for golden algae growth. The researchers also will biomanipulate nutrients in those hotspots to see what effect, if any, it might have on golden algae growth. They expect to have results in about two years.
Along the Brazos River, more than six-million fish have been killed since 1988 due to high golden algae levels, according to Texas Parks and Wildlife. In fact, just last year, thousands of dead fish washed up on the shores of Lake Whitney. But this was a small incident in comparison to a similar event in 2005, when more than a million fish died in the lake over a three-month period. Officials believe large golden algae blooms contributed to the deaths, attacking the fishes' gills causing them to suffocate.
For more information, contact Dr. Brooks at (254) 710-6553.