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Flooding and storm surge from last year's spate of hurricanes not only displaced thousands of people, it may have relocated hundreds of invasive aquatic species to new locations.

In response, the U.S. Geological Survey spent the past six months creating new "flood and storm tracker" maps to help biologists track where the more than 200 non-native aquatic species, including alligators and snails, may be setting up new residence after hurricanes Harvey, Irma, Maria and Nate.

According to a press release, the USGS created four interactive maps for each of the four large hurricanes that hit the U.S. in 2017 to track the movement of the invasive critters.

(MORE: FEMA to Hurricane Harvey Evacuees: Your Time in Hotels Is Up)

The maps indicate where lakes, rivers, streams and other waterways merged during the storms, which may have offered aquatic species the opportunity to spread.

One such species is the sailfin armored catfish, a South American species found in Houston’s Buffalo-San Jacinto watershed. It is believed sailfin catfish may have been spread to watersheds around Galveston Bay by Hurricane Harvey.

Pam Fuller, the leader of USGS’s Nonindigenous Aquatic Species Program, noted that Harvey's storm surge and flooding created temporary freshwater zones in saltwater environments, enabling freshwater species to take up new residence in other areas.

“USGS’s stream monitoring showed that as the rivers carried Hurricane Harvey’s floodwaters downstream, a freshwater area developed along the Gulf Coast in parts of Texas and Louisiana,” Fuller said. “Normally, the Gulf acts as a saltwater barrier that blocks freshwater species from moving along the coast. But that barrier was temporarily gone, and freshwater aquatic species could move into new habitats.”

The scientists used information from the USGS Nonindigenous Aquatic Species database and model data showing where waterways merged thanks to floodwaters and storm surge to determine where non-native aquatic species could have been relocated.

"The U.S. Geological Survey's Flood and Storm Tracker maps are terrific tools we now have available to help determine the spread of aquatic invasive fish, wildlife and plants caused by major storms like the hurricanes we had last fall," said John Galvez, who leads the Peninsular Florida Fish and Wildlife Conservation Office for the U.S. Fish and Wildlife Service. "The county-by-county maps are helping us make better decisions about where to target surveys and identify ways to eliminate the invaders before they get a foothold in new areas."