FROM THE NYSDEC---THE STURGEON WE DIDN'T KNOW WERE THERE

The Sturgeon We Didn’t Know Were There

For decades scientists understood the life cycle of Atlantic sturgeon in the Hudson River to be predictable. These endangered, prehistoric giants showed a straightforward pattern: they would enter the river from the Atlantic Ocean, journey upstream to freshwater spawning grounds for a brief visit, and quickly return to the sea. But now, a decade of movement data has revealed this familiar picture is incomplete. Individual sturgeon do not all follow the same biological clock. The Hudson River Atlantic sturgeon population may contain multiple groups with different behavioral strategies, one of which lingers in the river long after the others have left.

How do we know? To track these fish movements in the Hudson, researchers from DEC, Cornell University, United States Geological Survey, and Delaware State University utilized acoustic telemetry technology. The research team equipped individual sturgeon with small electronic transmitters that log the exact moment fish pass by an array of underwater receivers positioned throughout the river.

Analysis of over a decade of sturgeon telemetry data has enabled researchers to identify two distinct groups in the Hudson River. One group follows the well-understood spawning migration pattern in which fish enter, spawn, and depart. A second group, however, operates on a completely different calendar, arriving later in the season and remaining well into the autumn — on average 88 days longer than the first group. This group also spent most of their time in the lower, brackish reaches of the Hudson, far downstream from traditional spawning areas....Read the full story to learn more about these new developments in DEC's Atlantic sturgeon research.

All sturgeon were captured under NMFS permit #20340.

PHOTO---A Hudson River Fisheries Unit sturgeon biologist releases a fish after data collection. NMFS permit #20340.