Human Interference Worsens Hurricane Impacts On Coastal Ecosystems
The impacts of hurricanes on people are well documented, and can scar communities for years. But the ecological effects of storms aren’t as obvious.
Thanks to Hurricanes Irma and Nate virtually every county in the state saw some storm effects this year. The state’s beaches didn’t escape the damage either, according to U.S. Geological Survey oceanographer Kara Doran.
“Yeah we lost a lot of sand during Hurricane Irma,” Doran said.
She says the erosion would’ve been a lot worse if Irma had crawled up the Gulf Coast, as was initially predicted. But dunes and barrier islands that serve as habitats and buffers for the mainland still saw damage.
“If it goes over top of the island and into the bay and gets transported landward then it’s harder to replace that sand and costs billions of dollars to replace it,” she said.
From the human perspective, beach erosion threatens roads, hotels, houses, and restaurants, and therefore tax bases. Florida’s First Coast and Treasure Coast along the Atlantic saw dunes cut in half and beaches washed away, leaving boardwalks exposed or collapsing. But Doran says ecologically, a changing coastline isn’t necessarily bad in the long term.
“The beach does have a natural process of rollover where the island can keep pace with sea level rise and storms. And it turns out the birds actually really like that. And the turtles really like that,” Doran said.
"The beach does have a natural process of rollover where the island can keep pace with sea level rise and storms."
And Jack Rudloe says there could be other potential benefits as well. Rudloe runs the Gulf Specimen Marine Lab in North Florida.
“Whole big distributions of marine life take place,” Rudloe said.
He says the force of the storm can stir up nutrients and redistribute them, fueling a feeding frenzy for filter feeders.
“Well we all remember the movie Forrest Gump and he goes out, he’s the only boat out there and they withstand the hurricane and of course all the other boats are washed up and nevertheless there’s this gigantic bumper crop of shrimp,” Rudloe said.
But – the storms can be incredibly disruptive. Saltwater intrusion can flood marshes, upsetting delicate estuary environments. Wind can shred plants of their leaves. Even the redistribution of nutrients and sediment Rudloe mentioned can suffocate other organisms. That’s according to Rob Ruzicka, a coral scientist with the Florida Fish and Wildlife Conservation Commission.
“We have videos of sponges where you could see that the sediment layer must’ve been thick, several inches thick that the bottom of the sponges, large barrel sponges that are several feet in height, they died almost instantaneously,” Ruzicka said.
He says the sheer power of the storm surge ripped organisms out of the reefs in the Keys, and toppled corals the size of cars.
“Corals like that are several hundred years old. Three hundred, four hundred years old. So it’s quite significant that they had survived so many things and then during Hurricane Irma they were either toppled or they were crushed,” Ruzicka said.
He says a healthy reef ecosystem is adapted to handle storms, even benefit from them.
"Corals like that are several hundred years old...so it's quite significant that they had survived so many things and then during Hurricane Irma they were either toppled or they were crushed."
“But in the modern sense, corals are under a lot of stress, whether it’s from water pollution, whether it’s from warming sea temperatures, whether it’s from issues that are connected to ocean acidification, whether it’s to coastal development, there are a lot of threats,” Ruzicka said.
As long as human interference takes a toll on coastal ecosystems, they’ll be even more susceptible to future storm damage.
Hurricane season ends November 30th.