The perfect weather and water conditions have combined to allow toxic golden algae to bloom over the past few days, causing a fish kill in the Brazos River in Fort Bend County.
KILLER ALGAE - A dead carp washes up along the banks for the Brazos River near Richmond. Texas Fish & Wildlife officials say blooms of toxic golden algae are to blame (see related story this page).
The river has been relatively low for months, and over the past few days has taken on an increasingly green hue. Dead fish have been observed along the banks of the river east of the U.S. 90A bridge in Richmond, and near the Grand Parkway.
Sensing a meal, as many as 200 turkey vultures have moved in and begun roosting along the river in Richmond.
Game warden Barry Eversol said the changes in the river are being caused by golden algae, a microscopic plant that has increased its presence in Texas lakes and rivers, and began killing large numbers of fish about 20 years ago.
According to information from Texas A&M University golden algae (Prymnesium parvum) sometimes reproduces rapidly, depleting oxygen in water and releasing toxins that can kill fish, clams and other water-breathing animals.
Eversol said the algae thrives in weather such as Fort Bend County has experienced lately – cool nights and warm, sunny days. Also, the low, still water of the Brazos has contributed to the problem. Golden algae thrives in water with a relatively high salt content. The lack of rain and lack of fresh water coming from upstream has concentrated salt levels, making conditions ideal for Prymnesium parvum.
On top of that, what little water is flowing through the Brazos now is largely coming from water treatment plants along the river, Eversol said. These plants discharge water that is very low in oxygen and high in nitrogen and phosphates – similar to fertilizer.
“You just end up with a lot of dead water,” he said. As a result, fish die for lack of oxygen.
Eversol said the golden algae blooms aren’t being found in the length of Fort Bend County’s portion of the river, but are showing up in certain areas, such as Richmond and near Greatwood.
About the only thing that can be done to get rid of the algae is wait – either for an extended rain spell, or for spring to bring warmer nights. Either of those would bring unfavorable conditions for golden algae.
The plant has been gradually moving down the Brazos since at least the late 1980s. In 2001, golden algae was blamed for thousands of fish deaths in Possum Kingdom Lake. In the spring of 2003, 1.6 million fish died in Possum Kingdom Lake, 3.1 million fish in Lake Granbury and 1.3 million in Lake Whitney, state officials said. All are along the Brazos north of Fort Bend.
There has been no estimate of the severity of the fish kill locally, Eversol said.
Hmm..
Sorry to hear this.