Documenting the extent of invasion of this population has proven elusive in the past,īut the use of LLTs to target juvenile eels has documented a larger invasion extent than previously known in the study Were effective at documenting an increase in the invasion extent of ASE, from within 100 m of the Chattahoochee NatureĬenter pond outflow to 1.6 km away. Radius of the purported invasion point to estimate the spatial extent of their invasion in this system. We sampled 111 and 100 sites in 20 respectively, on 10 occasions, each within a 2-km Our objective was to delineate theĬurrent invasion extent of ASE in the Chattahoochee River, Georgia, by sampling juvenile ASE within an occupancy Ponds drained via an outflow pipe into marsh habitats along the Chattahoochee River. This population was first discovered within several ponds on a private nature centre, but the The first reported invasion of Asian swamp eels (Monopterus albus, ASE) in the continental United States was Understanding Asian swamp eel acute and chronic thermal limits may be useful in assessing dispersal risk and range expansion in the southeastern USA. Fringe populations of swamp eel in their native range periodically experience colder winter temperatures, which may explain the ability of introduced populations to survive winter cold fronts in Florida. ![]() Progressive time-series critical thermal minimum temperatures (CTmin) estimates for eel acclimated to 20.5 ☌ followed by an acute temperature decrease to 16.0 ☌, revealed that cold acclimation may occur in only 8 days. Swamp eel exhibited a moderate cold acclimation response, gaining 0.23 ☌ in cold tolerance for every 1 ☌ drop in acclimation temperature. During critical thermal minima trials, swamp eel exposed to acute temperature drops (0.25 ☌ min−1) tolerated temperatures as low as 6.2 ☌. When exposed to chronic temperature decreases of 1.0 ☌ day−1, swamp eel ceased foraging at 15.0 ☌, markedly diminished movements below 11.0 ☌, and became incapacitated near 9.6 ☌. We use standard thermal methodologies to quantify low temperature responses and provide a detailed description of swamp eel reactions to cold temperatures. Our results suggest that the continued spread of swamp eels may result in adverse consequences for Everglades trophic dynamics and potentially diminish benefits expected from the $20B+ restoration.Īsian swamp eel, Monopterus albus/javanensis, has been established in the southeastern USA since at least 1994, yet little is known about its ability to survive low winter temperatures. Water management may have facilitated the invasion of swamp eels. Ongoing Everglades restoration is designed to restore hydrological conditions that support production of crayfishes and fishes, and nesting wading birds reliant on them. Species most strongly reduced were those dependent on predator-free habitats at the onset of the wet season, indicating drought-resistant swamp eels have introduced novel predator effects and disrupted the hydrology-mediated production of aquatic animals that are prey for many larger predators. ![]() ![]() After invasion, populations of two crayfishes collapsed by >95 %, two fishes declined by >80 %, two fishes had intermediate declines of 44–66 %, and three species remained unchanged. ![]() Using a 26-year dataset that included a 13-year baseline period prior to swamp eel arrival in Taylor Slough, we assessed population changes of common small fishes and decapods that are important prey for larger vertebrate predators. While populations of native fishes in the Everglades are tied to the system's natural hydrological dynamics, Asian Swamp Eels (Monopterus albus/javanensis) are drought-resistant fish first reported from Florida in 1997 and the Everglades in 2007. Invasive species are one of the greatest threats to ecosystems, disrupting ecosystem function and leading to the collapse and extinction of native species.
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