Why thousands of fish washed up on these southeast Texas beaches

Most of the fish that were found dead in Quintana Beach County were small creatures called menhaden.

Quintana Beach County Park/Anadolu Agency via Getty Images

Over the past weekend, troves of dead fish appeared on the shores of multiple beaches in southeast Texas, after struggling to find enough oxygen underwater.

Quintana Beach County Park announced on Friday that dead fish were washing up by the thousands. The department warned the public to stay clear of the local beaches until all the fish had been cleared, due to risk of being exposed to bacteria and sharp fins.

Crews are continuing to clear the carcasses of dead fish, which park officials described as “shredded skeletons.” The Texas Parks and Wildlife Department’s Kills and Spills Team responded to the situation and determined the cause of the massive die-off was a “low dissolved oxygen event,” meaning fish essentially suffocated.

Here is what to know about what happened:

What caused the Texas fish kill

When asked what contributed to the fish deaths, Quintana Beach County Park officials said it was a “perfect storm” of factors.

First, warm water is not ideal for fish. It tends to hold less oxygen. That is especially true in shallow water, which heats up quicker. So, a school of fish likely found themselves deprived of oxygen as they swam though shallow waters in the summertime.

Another problem was that seas near county beaches were quite calm over the past few weeks, meaning there were few waves and winds to help redistribute oxygen in the water.

Over the past few days, the skies above the the beaches were cloudy. That is an issue for phytoplankton,…