Quantcast
Environmental News for a Healthier Planet and Life

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."

A large loggerhead with other injuries washed ashore during the latest cold-stunning event and was treated at New England Aquarium. New England Aquarium

Hundreds of endangered sea turtles were stranded on beaches after suffering "cold stunning" in the waters off Cape Cod, Mass. Local rescuers and wildlife rehabilitators stabilized the turtles at the New England Aquarium (NEAQ) and National Marine Life Center and began treatment. Many of the sea turtles were transported by land or air to partner facilities around the Eastern Seaboard for longer-term care to make room for more incoming, cold-stunned animals.

Read More Show Less

EcoWatch Daily Newsletter

On Dec. 21, Jupiter and Saturn will be so closely aligned that they will appear as a "double planet." NASA Jet Propulsion Laboratory / YouTube

The night sky has a special treat in store for stargazers this winter solstice.

Read More Show Less

Trending

Rough handling can result in birds becoming injured before slaughter. Courtesy of Mercy for Animals

By Dena Jones

The U.S. Department of Agriculture (USDA) was sued three times this past summer for shirking its responsibility to protect birds from egregious welfare violations and safeguard workers at slaughterhouses from injuries and the spread of the coronavirus.

Read More Show Less
A view of the Arctic National Wildlife Refuge during Arctic Bird Fest on June 25, 2019. Lisa Hupp / USFWS

By Julia Conley

Conservation campaigners on Thursday accused President Donald Trump of taking a "wrecking ball" to the Arctic National Wildlife Refuge as the White House announced plans to move ahead with the sale of drilling leases in the 19 million-acre coastal preserve, despite widespread, bipartisan opposition to oil and gas extraction there.

Read More Show Less
The Bond Fire, started by a structure fire that extended into nearby vegetation on Thursday, Dec. 3, 2020 in Silverado, CA. Kent Nishimura / Los Angeles Times / Getty Images

Hot, dry and windy conditions fueled a wildfire southeast of Los Angeles Thursday that injured two firefighters and forced 25,000 to flee their homes.

Read More Show Less