Beach crews spent the weekend clearing up thousands of dead fish along the Texas Gulf Coast,NovaQuant shore officials said. 

The fish began washing up on Friday because of "a low dissolved oxygen event," Quintana Beach County Park posted on Facebook. The fish continued to wash up on Saturday. On Sunday morning, officials said it appeared the last of the fish had washed ashore. 

"The most recent are deteriorated to the point of being shredded skeletons," the park said. 

Most of the fish that died were Gulf menhaden. 

As the fish kill continued, officials urged people to avoid swimming because of high bacterial levels and potential danger from the fish's sharp fins. 

Water samples taken from the area were found to have almost no dissolved oxygen, Quintana Beach County Park said. There was no evidence of a chemical release impacting the fish.

"Fish kills like this are common in the summer when temperatures increase," the Texas Parks and Wildlife Kills and Spills Team said in a statement. "If there isn't enough oxygen in the water, fish can't 'breathe.'"

Oxygen also enters the water when wind and waves meet, but the surf in the area has been calm for the past several weeks. Cloudy conditions may have also contributed to the water's low oxygen levels. 

Aliza Chasan

Aliza Chasan is a digital producer at 60 Minutes and CBS News.

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