Each spring the Hudson River is alive with migratory fish species that are drawn into the protective waters of the estuary as part of their spawning cycle. Estuaries provide smaller, shallower waterways with protection from the much larger fish that circulate in the ocean, along with a wonderful buffet of foods. Most of our migratory species are anadromous, meaning they live in the ocean and move into the Hudson just to reproduce. After spawning, most of the young fish spend only months in the Hudson, yet some can spend a year or several years here before moving back out to the ocean waters. We also see the migration of one catadromous species, the American eel. Catadromous fish spend most of their lives in the estuary and use the ocean as their spawning grounds. We see the young glass eels also moving into the Hudson during the late spring.

Each site included in our event will collect data during the fish count to support a better understanding of the migratory use of the estuary, along with the biodiversity of the lower Hudson. Collection methods vary from site to site, with many sites offering seining, rod & reel fishing, or traps as part of the event. The full set of data allows us to compare species richness and abundance to prior year spring fish counts and those that occur during other times of the year. The WFMD event builds on spring public fish count events that were organized from 2015 through 2019 as part of the World Science Festival, and we are thankful that there are so many wonderful partners that connect annually to make this annual event a success! The full set of data is shared here as part of our long-term data history with this year’s data to be added after the event!