A reported fish kill at Lake Murvaul appears to be over, but the Texas Parks & Wildlife Department said in a news release Wednesday they are still collecting water samples and investigating a potential cause.
TPWD said no new reports of dead fish or wildlife have been reported since May 3.
“TPWD is awaiting further results from additional lab cultures and information from Baylor University regarding cyanobacteria present in the water samples,” the news release said.
During an initial investigation, TPWD officials collected water at multiple locations and recorded affected fish — and found water quality was within acceptable ranges. Collected fish were sent to the fish health lab in San Marcos, and TPWD officials returned April 27 to continue surveying the western portion of the lake and collected more fish samples.
Suspected cyanobacteria blooms were reported May 3, and TPWD said water samples were collected and sent to Baylor University for testing. The Sabine River Authority also collected water samples to test for nutrient loads and chlorophyll-a content.
TPWD said Baylor University confirmed the presence of cyanobacteria, which can produce cyanotoxin, on May 6.
“Although it’s not certain cyanobacteria caused the kill, fisheries scientists are investigating that and other possibilities,” TPWD said.
TPWD’s lab reported the initial fish sample had a bacterial infection and that lab personnel would be growing the bacteria to see if an “opportunistic” pathogen was present.
“ Opportunistic pathogens are types of microorganisms that do not usually harm fish but can do so when a fish is not healthy enough to resist infection,” TPWD said.
TPWD said there is no conclusive research showing cyanotoxins make fish unsafe to eat, but any concerns about the safety of consuming fish from Lake Murvaul should be addressed to the Texas Department of Safety and Health Services Seafood and Aquatic Life Unit at firstname.lastname@example.org.