Integrating eDNA and Hydroacoustic Data to Assess Temporal and Spatial Variability of Alosa Species in the Kennebec River
Document Type
Event
Faculty Mentor
Karen Wilson
Abstract
Alosa aestivalis (Blueback Herring) and Alosa pseudoharengus (Alewife), collectively known as River Herring, are ecologically and culturally significant anadromous fish species across Maine and the broader East Coast. Monitoring in the Kennebec River currently relies on beach seining, a method with spatial constraints and unavoidable mortality. This study integrates environmental DNA (eDNA) with hydroacoustic data from Maine’s Department of Marine Resources to evaluate whether these approaches can provide more accurate, species‑specific monitoring of River Herring during their late‑summer and early‑fall out‑migration. Six sampling sites spanning from Phippsburg to Richmond, ME were sampled in July, August, and September, with one liter of surface and deep water collected at each site. DNA was extracted and quantified using real‑time qPCR, and hydroacoustic data was filtered to include only fish estimated at 3–9 cm. River Herring DNA was detected at all sites across all months except site one in July. eDNA concentrations showed no clear relationship with hydroacoustic counts but demonstrated some spatial and temporal alignment with beach‑seining results. These findings highlight both the potential and the limitations of combining eDNA and hydroacoustic data for non‑lethal, expanded spatial and temporal monitoring of River Herring, offering guidance for future fisheries research.
Integrating eDNA and Hydroacoustic Data to Assess Temporal and Spatial Variability of Alosa Species in the Kennebec River
Alosa aestivalis (Blueback Herring) and Alosa pseudoharengus (Alewife), collectively known as River Herring, are ecologically and culturally significant anadromous fish species across Maine and the broader East Coast. Monitoring in the Kennebec River currently relies on beach seining, a method with spatial constraints and unavoidable mortality. This study integrates environmental DNA (eDNA) with hydroacoustic data from Maine’s Department of Marine Resources to evaluate whether these approaches can provide more accurate, species‑specific monitoring of River Herring during their late‑summer and early‑fall out‑migration. Six sampling sites spanning from Phippsburg to Richmond, ME were sampled in July, August, and September, with one liter of surface and deep water collected at each site. DNA was extracted and quantified using real‑time qPCR, and hydroacoustic data was filtered to include only fish estimated at 3–9 cm. River Herring DNA was detected at all sites across all months except site one in July. eDNA concentrations showed no clear relationship with hydroacoustic counts but demonstrated some spatial and temporal alignment with beach‑seining results. These findings highlight both the potential and the limitations of combining eDNA and hydroacoustic data for non‑lethal, expanded spatial and temporal monitoring of River Herring, offering guidance for future fisheries research.
