Patrick McGrath researches the rare Atlantic sturgeon in waters around Maryland and Virginia, tagging the living-fossil fish to track their movements via receiver. He blogs about the project at the VIMS Sturgeon blog ( http://vimssturgeon.blogs.wm.edu), part of the Virginia Institute of Marine Science at the College of William & Mary.
Q. Whats special about the Atlantic sturgeon?
A. Atlantic sturgeon belong to an ancient group of fishes that date to the late Cretaceous. They are a large (historically up to 14 feet long) fish that have retained many primitive characteristics such as bony plates (scutes) and a sharklike tail. Atlantic sturgeon once were very common in estuaries along the Atlantic coast and were an important food source for Native Americans and early colonists. Unfortunately, in the late 1800s, the American caviar boom occurred, severely depleting Atlantic sturgeon populations. Add in barriers to successful reproduction such as dams preventing access to spawning sites and deforestation increasing the amount of egg-choking silt, and you have a species in need of remediation. Atlantic sturgeon are listed as an endangered species in four of the five distinct population segments, including both the Chesapeake Bay and the Carolinas.
Q. How are the fish handling changes in the waterways and climate?
A. Unfortunately, evolution does not typically occur fast enough to keep up with human-caused changes to the environment. Presently, it is illegal to fish for Atlantic sturgeon, which means the main barriers to recovery are the damming of rivers and degraded water quality. As populations and deforestation increase, the amount of run-off carrying excess sediments, nitrogen and other chemicals increases. The excess amount of chemicals leads to areas with depleted oxygen, limiting the available habitat to Atlantic sturgeon and other marine life using the bay.
Q. Where is your study going next?
A. We are currently in year two of this three-year study funded by the National Oceanic and Atmospheric Administration, so we will continue tagging large adults this fall, and sub-adults in the spring. In the long term, we hope to link the presence of large adults in the York River (in Virginia) system with the presence of Atlantic sturgeon eggs and larvae. We also plan on extending our efforts to other river systems and use underwater video technology to count the number of adults swimming to the spawning grounds.