Toxic red tide bloom along parts of Texas coast is killing fish, sharks

Red tide is a naturally occurring, higher-than-normal concentration of algae that produces toxins

Photos taken on Brazoria County beaches and San Bernard River delta area on Sept. 21, 2023. (Brazoria County Parks Department)

GALVESTON, Texas – A toxic red tide bloom appears to be killing fish and sharks in some areas along the Texas coast.

The Brazoria County Parks Department said Thursday that red tide is currently affecting Galveston, Brazoria and Matagorda Counties and that ocean currents are carrying the toxic algae across area bay networks.

Red tide is a naturally occurring, higher-than-normal concentration of harmful, microscopic algae that produces toxins.

The toxin affects the central nervous system of fish, paralyzing them so they cannot breathe, which often results in dead fish washing up on Gulf beaches, according to Red Tide in Texas.

Officials with the Texas Parks and Wildlife Department first reported a red tide event along the southern Texas coast on Sept. 3 in Freeport. Reports of red tide were then detected in water samples collected from Galveston County and the Rio Grande Valley Area on Sept. 18.

“Where concentrations of the red tide (Karenia brevis) algae blooms are present, corresponding incoming surf waters often have a reddish-rust cast, leaving similar color striping on beach sand at the tide lines,” Brazoria Parks staff said in a Facebook post. “These algal blooms release toxins, which kills fish and other marine life such as shellfish that are in the vicinity of the bloom.”

Parks officials said dead fish were being observed along the coast but noted that long-term health effects for people exposed to red tide are “largely unlikely.”

“Those standing near the water’s edge frequently experience respiratory / sinus irritation, discomfort and cough symptoms when exposed to the aerosolized algae toxins that disperse when waves crash onto beaches and shorelines,” parks officials said in the social media post.

Eye irritation can also occur for anyone who swims in water with a high concentration of red tide.

Brazoria County Park staff experienced similar symptoms when checking the beaches Thursday morning, which prompted them to cancel their participation in an upcoming statewide fall Adopt-A-Beach event.

“Other parts of the Texas coast will undoubtedly still participate in this annual beach cleanup. But out of concern for volunteers, Brazoria County fall Adopt-A-Beach efforts are canceled,” officials said.

To report sightings of red tide during normal business hours, call your local TPWD office. Outside of normal business hours, you can call TPWD’s 24-hour communications center at 512-389-4848.

About the Author:

Mary Claire Patton has been a journalist with KSAT 12 since 2015. She has reported on several high-profile stories during her career at KSAT and specializes in trending news and things to do around Texas and San Antonio.