Tens of thousands of dead fish washed up on the Texas Gulf coast over the weekend, blanketing the shorelines of several beaches with marine carcasses for miles.
Most of the dead fish were menhaden, a small fish often used for bait, and died due to "a low dissolved oxygen event," according to a Facebook post from the Quintana Beach County Park.
Fish kills like this are common in the summer as water temperatures rise, Texas Parks and Wildlife said. Many cases of low dissolved oxygen are natural occurrences.
A sufficient level of dissolved oxygen in water is necessary to sustain aquatic life. Warm ocean water holds less oxygen than cold water and can contribute to oxygen levels dropping too low, impacting water quality and starving fish of a life necessity. Recent samples taken from the beach showed almost no dissolved oxygen, officials said.
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“As we see increased water temperatures, certainly this could lead to more of these events occurring especially in our shallow, near-shore or inshore environments," said Katie St. Clair, the sea life facility manager at Texas A&M University at Galveston.
Last week, the National Oceanic and Atmospheric Administration announced the oxygen-depleted “dead zone” that forms each year in the Gulf of Mexico off Louisiana and Texas was forecast to cover about 4,155 square miles this year. The Gulf dead zone is largely created by urban and agricultural runoff and discharges of nitrogen and phosphorus to the Mississippi River, which drains 41% of the continental United States. In the Gulf, the nutrients feed an overgrowth of algae, which die and sink to the bottom, using up oxygen from the ocean floor as they decompose. Fish, shrimp and crabs can swim away. Animals that are slower or fixed to the bottom cannot.
Still, the sheer number of fish and area impacted has some scientists baffled. Julia Wellner, a glacial marine geoscientist at the University of Houston, tweeted Sunday her concerns over a "scary future."
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"Yesterday I took a dozen international visiting sedimentologists to Quintana Beach, TX. I might be an expert on some things on the beach but this fish kill baffled all of us. Went for miles. Low oxygen sure but why here and now? Why this dramatic? Scary future."
Park crews spent Saturday and Sunday removing the fish remains from the beach. Any dead fish remnants that were left behind or continue to wash ashore will be buried naturally in the sand and ocean over the coming days, park officials said.
Officials urged people to avoid the impacted beach because of high bacteria levels.
