The lower Hudson River Estuary is a dynamic region that supports a wide range of fish species. Hudson River Park monitors the presence of fish in the Park’s Estuarine Sanctuary waters primarily through the Fish Ecology Survey that is supplemented by environmental DNA collection and videographic surveillance.
The Fish Ecology Survey uses crab pots and minnow traps to catch and hold fish, which are identified, measured and either returned to the River or temporarily kept in the Park’s Wetlab Aquarium. This study was started by the original River Project in 1988, and has continued nearly uninterrupted for more than three decades. Since 2012, the survey traps are checked at least once a week, year-round, to provide robust and consistent data on the incidence of fish species in the Park. This study has identified 45 species of fish in the lower Hudson River to date.
The environmental DNA, or eDNA, study represents a newer survey technique to measure genetic material from the sloughed cells and feces of living marine organisms in our local waters. Sampling began in 2019 as Hudson River Park and Cold Spring Harbor Lab initially partnered to explore the effectiveness of eDNA as an educational tool and method to gather data on fish biodiversity in the Estuarine Sanctuary. These water samples are processed to isolate and extract the DNA present within the water and can be used to determine if particular species of fish are present within the sample.
With the addition of submerged video recording in 2020, these methods help to build a more complete picture about the fish species that inhabit our waters year-round.