The Gulf of Mexico Is Becoming So Polluted by River Water That Dolphins Are Dying in Record Numbers

Come summertime, beachgoers flock to the coast from Florida to Louisiana for the soft white-sand beaches and long, balmy days. But wade a little deeper into the water this year, and you’ll find marine life (and the fishermen who depend on it) still feeling the devastating effects of an unusually rainy spring.

According to the National Weather Service, the United States experienced its wettest 12 months on record from July 2018 through June 2019, and the second rainiest month ever recorded in May. While that’s good news for drought-prone regions, it’s not so hot for places prone to flooding. That includes many areas along the Mississippi River, from Minnesota to the Gulf of Mexico, which noted some of the highest water levels in history. (Tropical Storm Barry even sent the city of New Orleans into crisis mode in early July when storm surge threatened to overtop its levees.)

But as the catch-all for river flow—plus any unwelcome pollutants that tag along—the Gulf might be taking the biggest hit of all. In June, the NOAA noticed an unusual die-off of bottlenose dolphins along the Gulf coast. Since February, nearly 300 have washed ashore from Louisiana to the Florida panhandle—more than three times the normal rate. The NOAA declared the phenomenon an “Unusual Mortality Event,” which signifies a need to take action immediately.

While it’s too early to determine an exact cause, per the NOAA, signs are pointing to the inundation of river water. Many dolphins, who are saltwater-only creatures and tend to stay in their territories despite changing conditions, are being found with visible skin lesions, indicating an exposure to unusual amounts of freshwater. According to experts, river water can also be laced with chemicals, pesticides, and other pollutants, which could be contributing to the dolphin deaths.

Related: Scientists Have Discovered the Real Reason Why Whales Jump:

Decreased salinity in the Gulf is also affecting other sea creatures, including those that dolphins rely on for food. Local fishermen and aquatic farmers are feeling the pain of the floods, with decimated populations of crab, oyster and shrimp in estuaries. (The Louisiana Department of Wildlife and Fisheries reported a decrease in brown shrimp catches as large as 80 percent.)

The Army Corps of Engineers, which operates the spillway that allows river water to flood into the Gulf, argues that there are some environmental benefits to the operation, including improved water circulation, nutrient introduction, and restocking of fishery resources.

The NOAA is continuing to investigate the mysterious dolphin deaths. You can show your support for the fragile dolphin population by donating to the Institute for Marine Mammal Studies, a Mississippi-based organization that rescues stranded dolphins and other animals along the Gulf. And in the meantime, let’s all hope for clear skies this summer.