Hurricanes Bring Invasive Species, and These Maps Preview Where

The cane toad (Rhinella marinus) is one of many species that the 2017 hurricane season’s floodwaters could have spread to new habitats.
Photo: Brian Gratwicke (Flickr)

Pollution isn’t the only thing the 2017 hurricane season spread far and wide. Plants and animals were sloshed around by the storms too, and some wound up far from home, setting the stage for new ecological invasions.

That’s why the U.S. Geological Survey (USGS) has spent the past six months putting together a series of maps to help biologists track down unwelcome newcomers introduced by hurricanes Harvey, Irma, Maria, and Nate. The maps allow users to see where more than 200 non-native aquatic species, from snails to crocodiles, might have wound up thanks to the storms.


Matt Neilson, a biologist with the USGS Wetland and Aquatic Research Center, who helped create the maps, told Earther he hopes they help managers get the jump on any new invasive species.

Coqui frogs, native to Puerto Rico and introduced to South Florida, may have been spread across vast tracts of the Everglades by Hurricane Irma.
Image: USGS

Our overarching goal for this as a to help with early detection and rapid response efforts,” Neilson told Earther. “In invasive species management circles [that’s] a key goal. The best time to manage a non native species is at the start.”

Hurricanes can cause plants and animals to be swept far beyond their native habitat, whether via floodwaters or winds. Witness this confused pelican that was blown all the way to Nova Scotia by Hurricane Earl in 2010, or these manatees that wound up in a backyard pond after Irma struck Florida last year.


The new maps take a look at where non-native aquatic species could have been sloshed by combining information from from the USGS Nonindigenous Aquatic Species database and model data showing where waterways merged thanks to floodwaters and storm surge. Neilson said land managers could use the maps to track pests like applesnails, which have caused billions of dollars of damage to rice crops in Asia and are now present along parts of the Gulf Coast.

Adrienne Correa, a biologist at Rice University who’s been monitoring Gulf Coast ecosystems in wake of Harvey, told Earther she thought the maps “should be an extremely useful tool for researchers, managers, and students.” She hopes they can be expended to include additional regions like the U.S. Virgin Islands, as well as terrestrial and marine life.

Asian clams were already exotic to Puerto Rico. The new maps show regions they might have been spread by floodwaters and storm surge from Hurricane Maria.
Image: USGS

“For example, fire ants and tawny crazy ants are introduced species in east Texas and the hurricane is hypothesized to facilitate the spread of these ants,” Correa said in an email. (For an unforgettable mental image, check out these gnarly videos of hoards of fire ants rafting on Harvey’s floodwaters.)


Neilson agreed it’d be useful to extend the mapping to more species and places, something that could be accomplished on the marine side by tapping the Smithsonian’s NEMESIS database (great acronym). But mostly, he says the plan is to continue making maps like this after future storms.

“We’ve refined some of our internal tools to make this a faster process,” he said.


That’s good news because with the 2018 hurricane season nearly upon us (gulp), the species mix-ups are likely to get even messier.

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Maddie Stone

Maddie Stone is a freelancer based in Philadelphia.