MOBILE, Ala.— Mobile Baykeeper and the Center for Biological Diversity notified the U.S. Army Corps of Engineers today that they intend to sue over the Corps’ failure to protect threatened Gulf sturgeon from a massive dredging project in Alabama’s Mobile Bay. Gulf sturgeon are ancient animals capable of growing 9 feet long and weighing 385 pounds.

The Corps is directing a project to deepen and widen the shipping channel in Mobile Bay, where these giant fish spend their winters. During construction, the Corps plans to dredge millions of tons of sediment from the shipping channel and deposit it in Mobile Bay. Millions more tons of sediment will be dredged and dumped every year as part of annual maintenance.

“Learning that Gulf sturgeon spend so much of their lives in Mobile Bay is an exciting discovery, and it means they need help there,” said Lindsay Reeves, a senior attorney at the Center for Biological Diversity. “We have to make sure the Corps is doing right by these ancient creatures and protecting this important habitat from dangerous dredging.”

The Corps has a legal duty to consult with scientists at the U.S. Fish and Wildlife Service and NOAA Fisheries to make sure its dredging project does not drive Gulf sturgeon extinct or destroy the places they need to survive.

Gulf sturgeon have survived since the time of the dinosaurs. A 2023 study discovered that more than 200 of the animals spend their winters in Mobile Bay. From October to April, sturgeon return to the bay to fatten up before they migrate upriver to spawn. Gulf sturgeon feed on crustaceans, worms, mollusks and other bottom-dwelling organisms.

Dredging harms sturgeon because it sucks up their food sources from one site and buries them with sediment in another. Once these bottom-dwelling species have been dug up or suffocated, they take a long time to return, so sturgeon that depend on the bay will have nothing to eat. Dredging degrades water quality by stirring up sediment and pollutants, and sturgeon have been sucked into dredging pipes and killed.

Since subpopulations from Florida to Louisiana converge on Mobile Bay each year, protecting Gulf sturgeon in the bay means protecting sturgeon from across the Gulf South.

“Communities from Louisiana to Florida have been working to save this species for decades, and now we know Mobile Bay is critical to this effort,” said Cade Kistler of Mobile Baykeeper. “Improving water quality and habitat conditions by limiting dredge sediment dumping will enhance fishing and protect important habitats such as seagrass and oysters in Mobile Bay. Saving these sturgeon isn’t just about protecting them and their ecosystem, it’s about protecting the Bay that we fish, swim, and play in.”

Historically, Gulf sturgeon lived in rivers from Florida to Louisiana. At the beginning of the 20th century, they were nearly wiped out by commercial fishing and dam construction that blocked them from their spawning sites. Fishermen and conservationists banded together to stop the overharvest and defend the rivers where sturgeon live.

Gulf sturgeon were protected under the Endangered Species Act in 1991 and their spawning rivers, from Suwanee River in Florida to the Bogue Chitto in Louisiana, were protected as critical habitat in 2003. Mobile Bay was not included as critical habitat because the presence of sturgeon in the bay was not known at that time.