State biologists from Oklahoma and Texas are working together to investigate a minor fish kill near the Red River upstream of Lake Texoma. Biologists believe golden alga found in water samples taken from the area was to blame. This is the first time the naturally occurring toxin has been documented in Oklahoma, and officials view it as an isolated event.

Reports by area fishing guides Jan. 22 of dead and dying gar and shad in Lebanon Pool, a 150-acre off-channel lake in upper Lake Texoma, sparked investigations by the Oklahoma Department of Wildlife Conservation and the Texas Parks and Wildlife Department.

All the initial symptoms of the dead fish point to golden alga, according to Paul Mauck, south central region fisheries supervisor for the Oklahoma Department of Wildlife Conservation. The alga kills fish by releasing toxins into the water that cause fish gills to bleed internally. There is no evidence to suggest the toxins are a threat to human health.

Water samples taken from Lebanon Pool revealed high levels of golden alga, however, subsequent samples from the Red River upstream and downstream have been sent to Texas Parks and Wildlife Department fisheries lab in Waco, TX for further analysis.

"We’re going to keep a very close eye on this," said Kim Erickson, fisheries chief for the Oklahoma Department of Wildlife Conservation. "Right now we’re optimistic that this bloom will remain isolated in the Lebanon Pool, but biologists from both Oklahoma and Texas will be working in the area taking water samples and looking for any more fish kills."

Texas fisheries biologists were the first to discover a golden alga fish kill in inland waters in the Western Hemisphere when a fish kill was identified in the Pecos River in 1985. Since 2001, golden alga fish kills have occurred on 23 reservoirs in Texas. The toxin has also been linked to subsequent fish kills in North Carolina, South Carolina and New Mexico. This is the first reported finding in the Red River basin downstream of Lake Kemp, located southwest of Wichita Falls, TX.

Golden algal blooms typically occur in winter months, often leaving a golden yellow ring around the lake shoreline. Golden alga (Prymnesium parvum) is native to estuarine habitats around the world. It is not known if the alga is a native or exotic species to inland waters.

To learn more about golden alga log on www.tpwd.state.tx.us/hab. The site includes a wide variety of information about harmful golden algal blooms, including scientific research updates, frequently asked questions and up-to-date news.

Anglers who see a fish kill or potential golden algal bloom can the call the Oklahoma Department of Wildlife Conservation’s fishery division at (405) 521-3721.