Quantcast
Environmental News for a Healthier Planet and Life

Help Support EcoWatch

Hurricane Harvey Runoff Threatens Coral Reefs

Climate
Hurricane Harvey Runoff Threatens Coral Reefs
Rice University marine biologist Adrienne Correa takes samples at a reef in Flower Garden Banks. Jesse Cancelmo / Rice University

Hurricane Harvey's record rains didn't just unleash a torrent of floodwaters into the Gulf of Mexico—this freshwater could be harming coral reefs which require saltwater to live, according to new research.

After Harvey dumped more than 13 trillion gallons of rain over southeast Texas, researchers detected a 10 percent drop in salinity at the Flower Garden Banks National Marine Sanctuary, located 100 miles off the coast of Galveston, Texas.


"The salinity at one buoy on the reef dropped from 36 to 32 on Sept. 28, but it rebounded to 36 by Oct. 4, and it has been between 35 and 36 since then," said Rice University marine biologist Adrienne Correa. "We don't yet know what impact the low salinity had on the reef while it was there."

Globally, corals occur in a salinity range between 32 and 40, according to the SEOS Project, which notes that the "sudden decreases in salinity due to high freshwater input by rivers or torrential rains ... is seen as a second factor for the disappearance of massive coral reefs in front of large river mouths."

Similarly, the April 2016 "Tax Day Floods" in Houston also led to massive freshwater runoff that harmed coral reefs.

"In late July 2016 there was a partial die-off on the East Flower Garden Banks," Correa said. "We didn't know it was happening until a recreational dive boat happened to go out there and see it. Because we didn't know about the risk ahead of time, we couldn't sample on a timeline that made it easy to figure out a mechanism for the die-off."

This time, "with Harvey, we were able to catch the 'before' much better than we were in 2016," she noted.

Correa hopes Harvey's floodwater plume continues to travel down the coast to the southwest so it will miss the fragile reefs, since direct hit of floodwater would likely devastate the reefs.

However, she pointed out that even without a direct hit, it is possible that eddies and steering currents in the coming months could bring enough floodwater to the reefs to reduce salinity to dangerous levels.

A destroyed reef can greatly disrupt the larger food chain, as a variety of fish and other marine life depends on it. A report by the UN's Food and Agriculture Organization shows that coral reefs are responsible for producing 17 percent of all globally consumed protein. Crucially, coral reefs generate half of Earth's oxygen and absorb nearly one-third of the carbon dioxide generated from burning fossil fuels.

"When people look at the impact of hurricanes on coral reefs, they often look at physical damage or breakage of reef frameworks by waves and storm surge," Correa said. "Much less is known about the impacts of freshwater influx from the precipitation associated with a hurricane."

This fall brings three new environmental movies. David Attenborough: A Life On Our Planet | Official Trailer

This week marks the official start of fall, but longer nights and colder days can make it harder to spend time outdoors. Luckily, there are several inspiring environmental films that can be streamed at home.

Read More Show Less

EcoWatch Daily Newsletter

Amazon Employees for Climate Justice walk out and rally at the company's headquarters to demand that leaders take action on climate change in Seattle, Washington on Sept. 20, 2019. JASON REDMOND / AFP via Getty Images

The world's largest online retailer is making it slightly easier for customer to make eco-conscious choices.

Read More Show Less

Trending

Moms Clean Air Force members attend a press conference hosted by Senator Tom Udall (D-N.M.) and Senator Richard Blumenthal (D-Conn.) announcing legislation to ban chlorpyrifos on July 25, 2017. Moms Clean Air Force

The Trump administration's Environmental Protection Agency (EPA) released a risk assessment for toxic pesticide chlorpyrifos Tuesday that downplayed its effects on children's brains and may be the first indication of how the administration's "secret science" policy could impact public health.

Read More Show Less
Evacuees wait to board a bus as they are evacuated by local and state government officials before the arrival of Hurricane Laura on August 26, 2020 in Lake Charles, Louisiana. Joe Raedle / Getty Images

By Maria Trimarchi and Sarah Gleim

If all the glaciers and ice caps on the planet melted, global sea level would rise by about 230 feet. That amount of water would flood nearly every coastal city around the world [source: U.S. Geological Survey]. Rising temperatures, melting arctic ice, drought, desertification and other catastrophic effects of climate change are not examples of future troubles — they are reality today. Climate change isn't just about the environment; its effects touch every part of our lives, from the stability of our governments and economies to our health and where we live.

Read More Show Less
In 'My Octopus Teacher,' Craig Foster becomes fascinated with an octopus and visits her for hundreds of days in a row. Netflix

In his latest documentary, My Octopus Teacher, free diver and filmmaker Craig Foster tells a unique story about his friendship and bond with an octopus in a kelp forest in Cape Town, South Africa. It's been labeled "the love story that we need right now" by The Cut.

Read More Show Less

Support Ecowatch