Feds seek end to dredging limits that protect sea turtles

The federal government is close to undoing a policy that for 30 years has protected rare sea turtles from being mangled and killed by machines used to suck sediments from shipping channels in four Southern states.

The Army Corps of Engineers is in charge of keeping U.S. waterways clear for boats and ships. Since 1991, the agency has suspended dredging of harbors in Georgia, the Carolinas and Florida during warmer months when sea turtles are most abundant in coastal waters and females lay eggs on Southern beaches.

But, in the coming weeks, the Army Corps plans to begin scrapping those seasonal limits, starting with Georgia, after the National Marine Fisheries Service concluded last year that sea turtles protected by the Endangered Species Act can likely endure roughly 150 deaths anticipated annually from year-round dredging.

Conservationists are sounding alarms, saying the federal government is downplaying the threat to sea turtles’ long-term recovery while reversing a policy that has minimized the number of turtles crushed or dismembered after being sucked into dredges.

The Georgia environmental group One Hundred Miles is urging state officials to resist the change. Sustained efforts to reduce sea turtle deaths in the water and to catalogue and protect their nests on land have been credited with pushing nesting to record levels in the region in 2019. Scientists say the rebound is fragile but encouraging.

“We can’t afford to throw that all away now,” said Catherine Ridley, a One Hundred Miles vice president who also coordinates volunteers for nest counts on St. Simons Island, Georgia. “We put our blood, sweat and tears into this effort for decades. And it’s personal to us.”

Thousands of sea turtles that nest each spring and summer share their coastal habitat with busy seaports in all four states. The Army Corps relies on dredging to remove accumulated sediments and debris that can make shipping channels shallower and less safe to navigate.

Army Corps officials say they can eliminate seasonal dredging limits without putting sea turtles in greater peril. They cite both economic and environmental reasons for the change.

Limits since the 1990s varied by state, but roughly confined dredging to between December and March. Those decisions focused too much on sea turtles, while ignoring other protected species such as critically endangered North Atlantic right whales, said Nicole Bonine, environmental compliance and sustainability manager for the Army Corps’ South Atlantic Division.

“We’re saying we need the whole year to evaluate the best way to do it to reduce the risks to all species,” Bonine said. “So it’s not let’s just kill more turtles. That’s nobody’s goal. Our goal is to work with researchers to find ways to continue to reduce that risk.”

The Army Corps also expects year-round dredging will help alleviate project delays caused by states competing to hire a limited number of contractors within the same narrow timeframe.

“The ports are economic drivers for their areas and we need to keep those ports open,” said Debby Scerno, senior environmental planner for the agency’s South Atlantic district.

For decades, Georgia’s window for coastal dredging ended March 31. But the Army Corps plans to dredge the entrance channel to the Port of Brunswick in April or May. The project is expected to take three to six weeks, likely overlapping with the sea turtle nesting season. A second dredging project in North Carolina could start this summer.

Ramona McGee, an attorney with the Southern Environmental Law Center, has been tracking the looming changes. She said eliminating seasonal dredging limits is “an unjustified about-face.”

“These windows have been in place because resource agencies recognized they worked,” McGee said.

Giant loggerhead sea turtles, protected as a federally threatened species, nest during the spring and summer months on beaches from North Carolina to Florida. Smaller numbers of endangered green and Kemp’s ridley sea turtles lay eggs in the region as well.

A biological assessment the National Marine Fisheries Service published last year predicts dredging in the warmer months will kill 460 sea turtles between the four states over a period of three years. The agency’s report concluded that many deaths aren’t likely to “cause an appreciable reduction in the likelihood of survival.”

It’s a 50% increase in the number of dredging deaths the agency considered acceptable for sea turtles in its last biological assessment in 1997.

In memos to the Army Corps, the Georgia Department of Natural Resources has expressed reluctance to abandon seasonal dredging limits. The state agency notes warmer waters in the summer attract sea turtles in far greater numbers than during winter.

Mark Dodd, the biologist overseeing the Georgia agency’s sea turtle recovery program, said dredging during nesting season also means greater risk to adult female loggerhead turtles that don’t start laying eggs until age 30.

“Loggerheads are unique in that they have delayed sexual maturity,” Dodd said. “It takes 30 years to replace a female loggerhead that you lose through dredging.”

Georgia officials also dispute that dredging poses much threat to right whales during winter, when the whales give birth off the coasts of Florida and Georgia. Scientists estimate only about 360 right whales survive.

The National Marine Fisheries Service found no right whale deaths or injuries caused by dredgers or boats supporting dredging operations in the region when dredging was limited to winter. One possible case of a dredging barge bumping a whale was reported in 2005 but never confirmed.

Scerno of the Army Corps said the risk of killing even one right whale is too great.