Some of the beaches south of Houston were filled with dead fish over the weekend.
According to Texas Parks & Wildlife, thousands of fish, mostly Gulf menhaden, suffered from a "dissolved oxygen event," which is considered common in the summer.
"If there isn't enough oxygen in the water, fish can't 'breathe,'" Texas Parks & Wildlife said in a statement. "Low dissolved oxygen in many cases is a natural occurrence."
Dissolved oxygen events can be caused by a variety of factors, including warmer waters, calm seas and the slowing of photosynthesis on cloudy days.
Mass swarm of dead fish in Atlantic prompts European inquiry
France and the European Union are investigating why a giant trawler in the Atlantic Ocean released a massive swarm of dead fish.
Officials with Quintana Beach County Park, where the fish wash ashore, said there was no evidence of any chemical release.
Large amounts of fish first began washing ashore on Friday. At the time, officials did not know how big the "dead zone" was, but one fisherman reported seeing dead fish 10 miles out.
People were advised over the weekend to stay away from the beach as crews were brought in to remove the fish.
"We definitely advise that no one enters the water," Quintana Beach County Park officials posted on its Facebook page on Saturday.
On Sunday, officials said they believed the last dead fish washed ashore. They were mostly "deteriorated to the point of being shredded skeletons."
Quintana Beach County Park is open, but officials said it wouldn't hurt to wait a couple more days to let "everything settle" before making the trip to the shore.
