Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus) are an endangered fish species that lives along the east coast of North America from Canada to Florida. Atlantic Sturgeon are anadromous, which means that adults live in the ocean but return to the river where they were born to spawn, or lay eggs. Depending on the river, they may swim hundreds of miles upstream to reach the ideal habitat for spawning. Young sturgeon then live in the river for the first few years of their lives, before migrating out into the ocean. Atlantic Sturgeon can grow to be over 6 feet long and can live for 60 years.
The University of Georgia’s research on Atlantic Sturgeon movements is helping scientists and species managers better understand the details of the species’ migratory life cycle. By tracking the movements of adult sturgeon, we have a much clearer picture of when and where sturgeon spawn in Georgia’s rivers. In many northern rivers, Atlantic Sturgeon spawn only in the spring, but we now know that in Georgia, some sturgeon spawn in the fall instead. We have also seen evidence of juvenile and adult sturgeon from Georgia traveling up and down the whole East Coast, and detected many sturgeon from other populations visiting Georgia. By tracking the movements of 1-year-old sturgeon in the river estuaries, we now know much more about the extent of their nursery habitat, and what subadults do they do when the first leave their home river and head out into the coastal ocean.
Adam Fox releasing an adult Atlantic Sturgeon. Image credit: K. Morgan/UGA
Why This Matters
Atlantic Sturgeon were once harvested by humans for their eggs (caviar) and meat, but overfishing caused populations to decline substantially over the 1800s-1900s. Additionally, the construction of dams on many rivers blocked adult sturgeon from being able to swim upriver, preventing them from spawning. Although Atlantic Sturgeon are now protected from harvest, they still face a number of other threats, including habitat loss, water pollution, being struck by ships, and being accidentally caught in other fisheries. Because these fish are so slow-growing and long-lived, their populations have not yet recovered from these historic and ongoing threats.
By tracking the movements of Atlantic Sturgeon, we are able to better understand what kinds of habitats they use both in rivers and in the ocean, and to establish migratory patterns across seasons and during the decades-long lifespan of a fish. This information helps scientists and species managers identify and address specific threats to their populations. For example, our Atlantic Sturgeon telemetry data is regularly used to help determine the times of year when fish are least likely to be present, so that construction activities or dredging will have the least impact on this endangered species.