Tiny Eels, Big Impact: Center for the Urban River Counts 10,000th Glass Eel in Ongoing Hudson River Study

On March 10, 2022, Sarah Lawrence College’s Center for the Urban River at Beczak (CURB) counted its 10,000^th glass eel as part of the New York State Department of Environmental Conservation’s American Eel Migration Project. Sarah Lawrence juniors Kiki Quiros and Rachel Lynch and community volunteer Diane McKay comprised the team that made the find, along with CURB’s Outreach Coordinator Jason Muller.

CURB is now in its 9^th season of tracking migrating glass eels on their journey from the Sargasso Sea in the Atlantic Ocean to the Hudson River. The tiny, one-year old eels play an important role in the Hudson River ecosystem; due to their sensitivity to environmental changes, American eels are a key indicator species for the health of the Hudson. They also play a dual role in the river’s food chain, serving as a food source for larger fish, shorebirds, and birds of prey, as well as being predators themselves that keep the population of smaller species in the river in check.

CURB is one of about 15 sites that collect eel data in the Hudson River Watershed. Staff and volunteers check a fyke net stationed in a tidal marsh along the Hudson River daily, counting and weighing the eels and collecting weather and water quality data. CURB began its first season of sampling in 2014, and since that time hundreds of volunteers have been involved with the project, including students, scientists, school groups, and concerned community members.

Thanks to this research, scientists have been able gain a clearer picture of the status of the American eel, as well as implement real world changes to aid in the health of their population. After a sharp decline in the population of American eels in the Hudson River in the 1990s, through its work over the last nine years CURB has seen a marked improvement in eel counts. For example, from 2014-2017 CURB caught an average of 638 eels each season. This number increased dramatically from 2018-2021 with an average of 1,840 eels each year. Similar increases are being observed throughout the Watershed, which is an excellent sign for the health of the American eel population as well as the waters in which they live.

Explore CURB’s comprehensive eel data at www.centerfortheurbanriver.org/research/eels.html.