Juvenile Atlantic Sturgeon Sonic Tracking Project
Atlantic Sturgeon
Atlantic sturgeon stocks are at historically low levels or extinct in Atlantic coastal estuaries. There has been an interest in culture and stocking to reintroduce or to restore riverine populations. This interest led to experiments on sturgeon culture at the USFWS Northeast Fisheries Center in Lamar, PA. The stocking protocol suggests that sturgeon used for stocking be obtained from the same river to which progeny will be stocked. The second issue includes the broader question of when Atlantic sturgeon imprint to their natal river.
Biologist with hatchery-reared
Atlantic sturgeon
The culture studies at Lamar obtained mature adult fish from the Hudson River Estuary from 1992 through 1998. Approximately 350 older immature Atlantic sturgeon remain at the Lamar fish culture facilities. A cooperative effort between NYSDEC and USFWS allowed the release of approximately 200 of these fish from May to September into the Hudson River Estuary to monitor seasonal movement within the estuary and the near shore ocean and to identify subsequent spawning locations. We sonic tagged 25 of these fish and also captured and sonic tag large wild juveniles from the estuary for behavioral comparisons.
Objectives of the study:
- Identify specific habitat use and movement of wild pre-migrant juvenile Atlantic sturgeon in the Hudson River.
- Identify post release behavior, movement, habitat use, and emigrations rate of older immature hatchery Atlantic sturgeon of Hudson River origin released to the Hudson River.
- Determine long term movement and use of other estuaries along the Atlantic coast by Atlantic sturgeon of older immature fish stocked in the Hudson River.
The Players
Inserting sonic tag into
Atlantic sturgeon
Wild fish were obtained from ongoing sampling of pre-migrant juvenile Atlantic sturgeon, a part of an on-going sturgeon monitoring study in the Hudson River Estuary. Nine juvenile wild fish were sonic tagged and released during the last week of April 2004.
A total of 25 sonic tagged hatchery fish were released at three different locations. Ten fish were released at Norrie Point on May 12th (RM 84). Fifteen fish were released in Kingston on June 22nd (RM 95).
Stitches where tag was inserted
We track the sturgeon's movement two ways, with a mobile tracking unit (see photo on right) and a stationary array. We are out on the Hudson at least every other week "searching" for the tagged fish. When a fish is "heard" and pinpointed, we mark it with a GPS point. This allows us to determine seasonal habitat use in the estuary.
Remote Tracking Hydrophone
We also keep track of the fish that we "hear" and don't get an exact location on. This will allow us to determine the seasonal movement of the fish within the estuary. We will continue to track until the fish leave the estuary or the batteries die in the tags (they will function for 537 days).
Habitat Preferences
We have some preliminary data to show the habitat preferences of the wild sonic tagged sturgeon. Below is a map of Haverstraw Bay with the locations of the fish. When all sonic tagged sturgeon locations were examined, they were found most often in dynamic mud.
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