A significant fish kill event occurred on a Texas Gulf Coast beach Friday morning, leaving thousands of Menhaden fish dead. The incident, concentrated at Bryan Beach near the Brazos River mouth, was attributed to a combination of environmental factors creating a low-oxygen environment, according to Brazoria County officials.

Warmer water temperatures, a characteristic of shallow waters, played a key role in the die-off. As water temperatures climb above 70 degrees Fahrenheit, the water's capacity to hold oxygen decreases, creating a stressful environment for Menhaden. The shallow waters near the shore warm more rapidly, exacerbating this effect and potentially trapping the fish. This, coupled with cloudy conditions hindering photosynthesis in microscopic phytoplankton and macroalgae, further reduced oxygen levels, leading to hypoxia – a state of oxygen deficiency that disrupts the fish's ability to maintain normal bodily functions.

The combined effect of these factors created what officials described as a "perfect storm" for oxygen depletion in the near-shore waters, resulting in the mass fish kill. Clean-up efforts are underway, but the removal process is dependent on receding tides.