Use of pop-up satellite archival tags to identify oceanic-migratory patterns for adult Atlantic Sturgeon, Acipenser oxyrinchus oxyrinchus Mitchell, 1815

Oceanic-migratory behavior of adult Atlantic Sturgeon, Acipenser oxyrinchus oxyrinchus, was examined using pop-up satellite archival tags (PSAT). Twenty-three Atlantic Sturgeons were caught and tagged with PSATs in the Hudson River, New York during 2006 and 2007. Fifteen of those fish returned to the ocean (with PSATs attached) 6-132 days after tagging. These PSATs remained attached to fish for a period of 108-360 days archiving light, temperature, and depth, before releasing from fish, ascending to the surface, and transmitting data to satellites. The location of PSATs was measured to within +/- 150 m by satellites using Doppler shift of radio transmissions within hours after tags reached the surface. Positions prior to pop up were initially estimated using only archived-light data and the tag manufacturers' proprietary software. Positional error associated with light-based estimates is high, especially with regard to latitude. This error was reduced by applying depth, distance, and temperature filters. Thirteen of the 15 Atlantic Sturgeons that left the Hudson River with PSATs attached remained within the Mid-Atlantic Bight for up to 1 year after tagging. Their geographic distributions generally extended from Long Island, New York to Chesapeake Bay at depths between 5 and 40 m. Aggregation areas were identified off southwest Long Island, along the New Jersey coast, off Delaware Bay, and off Chesapeake Bay. Depth distribution was seasonal; fish inhabited deepest waters during winter and shallowest waters during summer and early fall. Two Atlantic Sturgeons traveled outside of the Mid-Atlantic Bight. One migrated north to Cobequid Bay (terminal end of the Bay of Fundy, Nova Scotia), whereas the other traveled south to the coast of Georgia.