Thousands of Fish Suffocate as Warming Waters Deplete Ocean of Oxygen

Warming ocean waters killed thousands of menhaden fish, the carcasses of which washed ashore on a beach in Texas on Friday.

Menhaden fish—a type of foraging fish sometimes referred to as the most important fish in the sea because of its filter feeder properties—can suffocate when water temperatures exceed 70 degrees. Although this can happen regularly in the summer months, some meteorologists predict it will happen more frequently as climate change continues to impact ocean temperatures.

Warming waters are one of the side effects of climate change, with experts expecting the phenomena to fuel more severe weather events. Such events have spanned the gamut from torrential rains over the winter in California to severe drought that creates abundant fuel for voracious wildfires, such as those currently tearing through western Canada.

AccuWeather senior meteorologist Brett Anderson told Newsweek on Monday that with the Gulf of Mexico warming at twice the rate of the rest of the world's oceans, less oxygen reaches the lower levels of the gulf.

"When the water gets warmer, we end up getting these dead zones where there's not as much oxygen and certain fish can die out quickly," he said, adding that he expects the problem to continue in the coming decades as climate change intensifies.

The fish casualties baffled people as waves in the Gulf of Mexico washed the fish ashore. The Weather Channel shared a video on its website from Quintana Beach County Park in Freeport, Texas, on Friday that showed the silver fish being washed ashore by the waves.

Quintana Beach County Park advised residents to steer clear of the beach over the weekend as officials conducted a mass clean-up as the fish continued to wash ashore over a period of days. The park called a series of weather events a "perfect storm" that contributed to the deaths.

"Shallow waters warm more quickly than deeper, so if a school of menhaden are trapped in the shallows as the water begins to heat, the fish will start to suffer from hypoxia. This causes fish to act more erratically, which in turn, further depletes the oxygen from the water. Low oxygen can cause menhaden to die in this manner," the park wrote in a Facebook post on Saturday, adding that oxygen enters water through surface mixing when air meets the water through wind and waves.

Oxygen also is created in the water through photosynthesis, the park added, which has lessened recently due to lack of sunlight because of cloudy skies.