Fish began washing up on the Texas Gulf Coast in the tens of thousands on Friday, presumably due to a lack of oxygen in the water.
Brazoria County park officials said they were working to clean up the mess, but that thousands more fish will likely wash up on the coast.
On Saturday, authorities at Quintana Beach County Park released photographs showing hundreds of dead fish in the ocean.
According to Brazoria County Parks Department Director Bryan Frazier, a “perfect storm” of adverse circumstances was to blame.
He said that the area’s calm waters and dark sky had rendered the traditional methods of injecting oxygen into the ocean water ineffective. Oxygen is added to the ocean by the waves, while photosynthesis by tiny organisms is inhibited by gloomy sky.
Fish schools might behave abnormally while they’re suffocating in warm, shallow water, which further depletes the oxygen supply.
The marine life facility manager at Texas A&M University–Galveston, Katie St. Clair, has speculated that climate change’s warming of gulf coast waters may have had a role in the mass fish mortality.
Fish deaths, which Mr. Frazier said are “not that uncommon” in the region, often begin in the summer when the water temperature rises.
In 2019, the United Nations issued a study warning that rising sea temperatures were harming fish populations by increasing the frequency with which coastal waters experienced hypoxia, or low oxygen levels. At the time, one of the report’s authors warned that a lack of oxygen and other consequences of climate change would “create enormous pressure” on the Gulf Coast.
In the summer, the Gulf of Mexico is home to a massive “dead zone” of water that spans hundreds of square miles due to widespread hypoxia.
On Monday, the National Oceanic and Atmospheric Administration predicted that this dead zone, which typically covers roughly 4,155 square miles of coastal waters, will be less than normal this year.
Due to their “critical role” in the local ecology, the dead fish — mostly Gulf menhaden — were cited by Ms. St. Clair as a possible source of serious environmental damage.
Park employees were swiftly deployed to clean and bury the dead fish before they rotted in the noon heat on Friday, Mr. Frazier said. Brazoria County is located about 65 miles south of Houston.