MidHudson News is reporting how biologists from the state Department of Environmental Conservation’s Hudson River Fisheries Unit annually study the endangered adult Atlantic sturgeon when the fish return to the Hudson River to spawn. Atlantic sturgeon is the largest fish species in the Hudson River Estuary. They are anadromous, which means they hatch in freshwater, spend most of their lives in saltwater, and then return to freshwater to spawn. Atlantic sturgeon can live more than 60 years, reaching a weight of 800 pounds and a length of 14 feet. They are armored with bony plates, evidence of a lineage going back to the age of dinosaurs. Sturgeon are bottom feeders, eating chiefly worms, insects, crustaceans, and small fish. During the annual study, the fisheries crew set nets to catch the sturgeon, carefully moving the fish from the nets into a large pen in the Hudson, tied to the boat. Crew members then weigh and measure each fish, determines its sex, and scan them for an electronic tag, called a PIT tag. If no tag is detected, a crew member inserts one into the base of the dorsal fin. The sturgeon are immediately released back into the Hudson River as soon as they are examined. The tags can be scanned to help learn more about sturgeon movement and behavior. Atlantic sturgeon are known to migrate as far south as Georgia and as far north as Canada’s Bay of Fundy. The Hudson River currently supports the largest population of Atlantic sturgeon along the Atlantic Coast, estimated to be between 1,000 and 1,500 fish. Read the full story at MidHudsonNews [dot] com.