Sturgeon Sojourns

No homebodies, those Atlantic sturgeon. Fish tagged in the Hudson River in New York State can be found roaming as far afield as Georgia and Nova Scotia, according to a new tracking study. The maps come just as the U.S. government has proposed giving the ancient fish protection under the Endangered Species Act, and suggest it could be a complicated task.

Sturgeon are one of the world’s oldest types of bony fish, first appearing in the fossil record some 200 million years ago. Today, there are 26 species, including the Atlantic sturgeon (Acipenser sturio), which ranges from Canada to Florida. It lives much of its life in brackish coastal waters and nearby seas, but spawns in freshwater. Biologists have found Atlantic sturgeon in at least 35 U.S. rivers, and believe they spawn in 20.

The fish — which can live 60 years, and grow to 800 pounds and 15 feet long – was heavily overfished in the late 1800s. In 1998, killing sturgeon was outlawed and last year the Natural Resources Defense Council petitioned the U.S. Fisheries Service to declare it endangered. On October 5, the agency agreed, issuing a plan that calls for listing a Gulf of Maine population as “threatened,” and fish from the Chesapeake Bay, the New York Bight, the Carolinas, and the South Atlantic as “endangered.”

The new study, however, suggests managing sturgeon “as separate and distinct groups” will be “very difficult, if not impossible,” says Daniel L. Erickson of the Oregon Department of Fish and Wildlife. He is a primary author of the study, set to appear in the December Journal of Applied Ichthyology. To track the fish, the researchers tagged them with electronic devices that “pop up” to the surface after a certain period and send their coordinates to a satellite. The tags revealed three major sturgeon aggregation areas off Long Island, the New Jersey shore, and Delaware Bay – but also that a few fish traveled as far north as Cobequid Bay off Nova Scotia, and south to Georgia.

The study “provides the most comprehensive picture of the migratory behavior of sturgeon in the ocean to date,” says Ellen Pikitch of Stony Brook University in New York. But it also confirms that different populations mix offshore, highlighting the need to protect the fish both at sea and in rivers. Currently, one major threat comes from nets set offshore to catch other species. “Effective restoration policies for sturgeon must consider threats to the species throughout their life cycle,” she says. The public can comment on the proposed sturgeon listing through January 4, 2011. – David Malakoff | October 7, 2010

Sources: “NOAA Proposes Five Atlantic Sturgeon Populations for Listing as Endangered or Threatened.” October 5, 2010.

“Study Provides Data That Can Inform Atlantic Sturgeon Recovery Efforts.” October 06, 2010.

Image NOAA Fisheries Service