Federal Agency: National Park Service (NPS)
Academic Institution: Oklahoma State University (OK STATE)
NPS Project Manager: Deanna Greco
Principal Investigator: James M. Long, U.S. Geological Survey (USGS), Oklahoma Cooperative Fish and Wildlife Research Unit
MS Student: Jeffery Johnson, Department of Natural Resource Ecology and Management, Oklahoma State University
Project Summary
The Asian Swamp Eel Monopterus albus has been introduced into five broad areas of the Unites States (Hawaii, New Jersey, Florida, and Georgia), primarily through the live food market or aquarium trade. The first introduced population in the continental US was discovered in Roswell, Georgia ca 1994 at spring-fed impoundments at the Chattahoochee Nature Center (CNC) bordering Chattahoochee River National Recreation Area (CRNRA), a unit of the National Park Service (NPS).
Asian swamp eels are well suited to become invasive in their nonnative range because they can breathe air, move over land, and resist desiccation. Furthermore, this species is a protogynous hermaphrodite, with all individuals starting life as female and transitioning to male as they grow. Males construct a burrow to entice females for spawning and when successful, males guard the developing brood inside their mouth to ensure reproductive success. It has been speculated that the nearby Chattahoochee River is a barrier to their dispersal because it's an artificially cold-water trout fishery. This population has persisted for more than 20 years with recent captures of young-of-year fish in marshes adjacent to the river, but it is unclear if these fish represent successful spawning in the marsh or emigration from connected ponds at the CNC where water temperatures are thought to be more suitable.
This project has two main objectives:
- To determine the invasion extent of Asian swamp eels in marshes adjacent to the Chattahoochee River. For this are using leaf-litter traps to capture young-of-year eels, which are more plentiful than adults, and water sampling to detect eDNA specific to Asian swamp eels
- To determine if eels captured in the marsh were the result of emigration from the ponds or reproduction in-situ. For this we are pursuing the examination of chemistry of the otoliths (inner ear bones) to detect differences in composition that may be specific to ponds and marshes.
Pursuing these two lines of inquiry will enable managers to better understand the scope of the invasion and plan for future control or eradication measures.
