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Are non-native fish hurting or helping different ecosystems across the Everglades?

Are non-native fish hurting or helping different ecosystems across the Everglades?

June 30, 2020 at 4:38pm

Normally, jewelfish are found in the Nile or for sale in pet shops. Today, they can also be found swimming around in an unlikely place: The Florida Everglades.

Peter Flood wants to understand if these non-native fish are hurting or helping different ecosystems across the Everglades.

Jewelfish first began to appear in South Florida waterways in the 1960’s after they were dumped by their owners. Traveling through the canal systems, they eventually made their way into the Everglades. Their population rapidly began to grow in 2012.

There hasn’t been a lot of research on how jewelfish are interacting with other native fish. Flood, a biology Ph.D. student in the FIU Institute of Environment, wants to fill that void.

“They are definitely changing things,” Flood said. “A lot of times with non-native species, in general, there is a perception that they may be helpful in one dimension. But there are probably dozens of other dimensions where they are having a negative impact.”

Flood is going to be looking at these different dimensions. He points out just because a species is introduced to a new ecosystem doesn’t necessarily mean it will cause massive disruption.

Using metal enclosures, Flood is studying the fear response of jewelfish to Florida Gar, a native predator fish. He will also be measuring the impact jewelfish have on their prey. Jewelfish emit chemical cues through the enclosures into surrounding water that can be detected by their prey. If the prey are too afraid, they won’t enter the enclosure. That means the jewelfish won’t eat.

“The larger implications are jewelfish are not as influenced by the native predator, which gives them a competitive advantage,” Flood said. “Jewelfish may also elicit a stronger fear response from their prey which could impact population and community dynamics of those prey species as well as for the populations of other species that rely on them as food such as wading birds.”

Peter Flood is working under the guidance of marine scientist Joel Trexler.  His work is funded in part by the Everglades Foundation’s FIU For Everglades Scholarship. 

Angela Nicoletti contributed to this story.