The Florida Everglades is having an ecological crisis beneath the water’s surface. A recent study published in Science of the Total Environment shows that the Asian swamp eel, which has been spreading through the Everglades since 2010, has drastically impacted native crayfish and fish populations. Researchers found that the Everglades crayfish and slough crayfish populations have fallen by 99 percent. Additionally, the flagfish population has declined by 99 percent, and the marsh killifish by 91 percent.
The results are striking—and prompted the researchers to write that the effects of the invasive swamp eels are “comparable to or exceeding the effects of the Burmese python invasion.”
The Burmese python has been an infamous invader in the Florida Everglades for decades. The python’s spread has led to severe mammal population declines in the Everglades National Park. The state has led a concerted—and highly publicized—hunting and removal program to try to control the population. The swamp eels, in contrast, have yet to grab the attention of the public—but their destructive power can’t be discounted.
The Asian swamp eel has both gills and lungs and is resistant to drought conditions. Where crayfish and other species were once able to enjoy a predator-free existence during natural drought conditions, the swamp eel has entered the equation. The crayfish are no longer are protected during those periods, which means the populations have plummeted as the eels have indulged. “It’s potentially the worst species we’ve had yet,” Matthew Pintar, one of the paper’s authors told the Miami Herald.
The swamp eel could also have sweeping impacts on the effectiveness of Florida’s billion-dollar-plus Everglades restoration project. The report states that the continued proliferation of the eels “could compromise an aim of restoration — increasing wading bird prey availability.” In other words, if the swamp eel continues to spread, prey availability may not increase or rebound even if waterway restoration efforts are successful. The swamp eel also could also threaten alligator populations.
And the problem may not be confined to the Everglades. The researchers concluded their report with a note of concern that swamp eels could spread “throughout peninsular Florida” and other wetland ecosystems in the Southeast.