BRAZORIA COUNTY, Texas – Officials from Brazoria County Parks spent the weekend cleaning tens of thousands of dead fish that washed ashore Quintana Beach County Park over the weekend.
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The parks director said most were menhaden or shad.
“They’re kind of the front line for that. They’re impact first and the most,” said Bryan Frazier, Brazoria County Parks Director.
Texas Parks and Wildlife Department Kills and Spills Team investigated the disturbance and, in a statement, said the cause for the recent fish kill is due to low dissolved oxygen.
“Fish kills like this are common in the summer when temperatures increase. If there isn’t enough oxygen in the water, fish can’t ‘breathe.’ Low dissolved oxygen in many cases is a natural occurrence. Daily variations in dissolved oxygen concentration are attributed to photosynthesis and aerobic respiration,” the statement reads.
Lucia Ross, with water treatment company BlueGreen Water Technologies, adds the recent rise in temperature contributed to the low dissolved oxygen.
“The result of a lack of oxygen in the water and the fish are going through hypothecia because that oxygen is being sucked out of that water due to the warmer conditions on the water because of the warm weather,” Frazier said.
Frazier said the fish kill didn’t surprise him, but the quantity did.
“There’s a higher concentration this time than there have been the last few years,” said Frazier. “It was the most in the last few years.”
Frazier explains that most of the fish that came ashore remain on the beach – underneath sand dunes.
“You want the dunes to be in really good shape and healthy, and that will help do that. It manages the wet beach, manages the stuff that comes down the rivers,” Frazier said. “But also, the sand dunes are really important. They’re important to habitat, they’re important for protecting the infrastructure that’s on the other side.”
Full statement from Texas Parks and Wildlife Department Kills and Spills Team:
“According to the Kills and Spills Team in Region 3, the fish kill was investigated and it was determined to have been caused by a low dissolved oxygen event. The species most impacted was tens of thousands of Gulf menhaden. Fish kills like this are common in the summer when temperatures increase. If there isn’t enough oxygen in the water, fish can’t “breathe.” Low dissolved oxygen in many cases is a natural occurrence. Daily variations in dissolved oxygen concentration are attributed to 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. 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. Some fish may also be lying on the bottom or at the edge of the water.”
“If you see a fish or wildlife kill or suspect a pollution event, please call (512) 389-4848 or contact your regional Kills and Spills Team biologist. Prompt notification is key to a successful investigation. The sooner we arrive, the better the chances that our biologists will be able to collect useful evidence.”