Officials are asking beachgoers to steer clear of a Texas beach after thousands of dead fish began washing up on Friday.
The “fish kill” on the Gulf Coast beach, about 65 miles south of Houston, was a result of low dissolved oxygen levels in the water, according to Texas Parks & Wildlife. Low oxygen levels are common in the summer when temperatures rise, making it so the fish can't "breathe" underwater, the department said.
The fish, most of them Gulf menhaden, which are often used for bait, washed up “by the thousands.” Video showed thousands of fish carcasses on the surface of the water at Bryan Beach.
Officials with Quintana Beach County Park urged swimmers to avoid the coast, citing high bacterial levels and the sharp fins of the dead fish.
"Our recommendation is that you avoid the beach altogether until this event is over," the officials said on Facebook. "We definitely advise that no one enters the water."
Cleanup efforts started Friday and wrapped up Sunday. when the last of the remains — "deteriorated to the point of being shredded skeletons" — had washed onto the shore, officials said.
Even after the cleanup, local officials suggested visitors wait a couple of days before they head to the beach.
Water samples taken from the Gulf Intracoastal Canal and the Brazos River, which feed into the coast, were found to have almost no dissolved oxygen in them, local officials said.
The Texas Parks & Wildlife Kills and Spills Team said low dissolved oxygen levels are water is "a natural occurrence" resulting from photosynthesis and aerobic respiration.
"Increased dissolved oxygen during the day is a result of photosynthesis which is driven by sunlight. Photosynthesis stops at night and may slow down on cloudy days, but plants and animals in the water continue to respire and consume free oxygen, decreasing the dissolved oxygen concentration," the department said in a statement.
"Often before a kill event occurs, fish can be seen trying to get oxygen by gulping at the surface of the water early in the morning," it added.
Quintana Beach County Park officials said there was no evidence that a chemical spill caused the mass fish kill event.