Utilizing Eel Ramps, eDNA, and Plankton Sampling to Monitor American Eel Recruitment in Texas
The purpose of this study is to better understand the recruitment of American eel in Texas, providing critical data required by resource management agencies to determine the conservation and management needs of American eel populations in Texas.
The objectives are:
- Build, install, monitor, and provide maintenance for up to 12 eel ramps along the central to upper Texas Coast
- Collect eDNA samples at a subset of the eel ramp sites to document the presence of American eels
- Utilize active or passive plankton nets in coastal passes and rivers to document the presence of leptocephalus American eel
Central to upper Texas coast (Matagorda, Galveston, and Sabine Bay systems and adjacent coastal areas)
2022 - 2023
The American eel (Anguilla rostrata) is a catadromous panmictic species of greatest conservation need in Texas. In-water diversions and water control structures pose a potential threat to American eel because of their highly migratory, catadromous life history. An important area of study is the recruitment of juvenile (glass eel and elver) stages to the coastal waters of the state. This recruitment or ingress of glass eels and elvers is likely to regulate the long-term local population success of the species. Recently, extensive field efforts to document recruiting American eels along the Texas coast have not been successful at detecting any individuals. As a result, recommendations to explore other novel methods to document recruitment along the Texas coast have been made. The findings of those field studies suggest that a continuous-passive gear deployment (e.g., eel ramps and plankton nets) as well as other novel sampling methods such as eDNA be utilized to build upon past efforts to document recruitment along the Texas coast.
During this study EIH researchers will construct and deploy 10 to 12 eel ramps specially designed to target ingressing glass eels and elvers along the central to upper Texas Coast with weekly checks for one year. Additionally, a pilot-scale effort to utilize plankton nets at Gulf of Mexico passes and near coastal river mouths in an effort to detect ingressing juvenile eels. Finally, we will utilize eDNA sampling to detect the presence of American eel. These data will provide baseline information for detecting the spatial and temporal recruitment of American eel to the Texas Gulf Coast. This critical information will assist natural resource agencies in determining the conservation and management needs of American eel populations in Texas.