Monitoring the American Eel


On Saturday, May 12th, members of the MSNH ventured to the Center for the Urban River at Beczak, Yonkers (CURB; Sarah Lawrence College) to experience first-hand the annual migration of tiny American Eels in the Hudson River (Anguilla rostrata). Upon our arrival, Jason Muller from CURB gave us a presentation of the intricate life cycle of these fascinating fish which are considered catadromous, as they migrate as adults from freshwater bodies, like the tributaries of the Hudson River, into the ocean, in this case the Saragossa sea south of Bermuda, to lay their eggs (other fish, like salmon do it the other way around). Once hatched in the Saragossa sea, the larvae will passively follow the Gulf Stream current to reach the continental shelf as "glass eels," tiny transparent eels, which eventually will enter the Hudson and its tributaries, and other fresh water bodies found at the East Coast. Here, they mature, and this can take anywhere from 15 to 20 years in the wild.


The Center for the Urban River catches and releases glass eels with a complex funnel net system every spring to estimate changes in population size. While most of the migration usually happens in March and April, this year has proven to be an unusual year as glass eels were still caught in May! During our visit to CURB, the MSNH was able to participate in this survey. We  put on waders provided by CURB, and recorded various water measurements (e.g. water temperature) and checked the funnel nets. The tide was low, so we could walk right through the mud (all but some of us successfully avoided to fall into the mud!) and sift whatever was caught in the net. Sure enough, among many amphipods there it was: a small wiggly glass eel! After recording the late arriver, it was released, all of us wishing it a long and successful life. Once our recording was finished, a few MSNHers stayed behind to join an annual spring celebration of CURB, while the rest of us returned back to NYC, with a better understanding of how important the Hudson River is for the growth and development of many animals, including eels. Who would have known!

To view more photos from this event, visit here. All photo credit goes to Harald Parzer.


Jason Muller is the Outreach Coordinator, at Center for the Urban River at Beczak (CURB), Sarah Lawrence College (SLC). He has a B.A. in Environmental Studies, and an M.S. in Educational Technology from Ramapo College, New Jersey. Muller joined Beczak Environmental Education Center, now the SLC CURB, as an educator in 2008 and since then has also taken on the role of Outreach Coordinator. His duties include developing and teaching hands-on Hudson River themed youth programs. When Muller isn't in the classroom, he is working in the field with CURB’s dedicated team of volunteers. For the past 5 years he has headed up the Yonkers site for the NYSDEC’s American Eel Migration Study. This program tracks migrating glass eels from the Atlantic Ocean into the Hudson River Watershed. Muller has also previously held positions at New Jersey Meadowlands Commission’s Meadowlands Environment Center, Brookdale Community College’s Ocean Institute at Sandy Hook, and served as Park Ranger/Education Specialist for the National Park Service's Gateway National Recreation Area.

Useful Links/Information

Center for Urban River Beczak

The American Eel Project

American Eels