Michelle Pate answered a 3 a.m. phone call. Even before speaking, she knew it was about a dead turtle. She also knew how it died.

Only the dredge crew called in the middle of the night.

Pate works for the S.C. Department of Natural Resources, and her phone serves as a sort of dead sea turtle hotline. On that day — May 6, 2021 — it rang once before dawn and four more times before dusk. Eventually, she drove to the docks of Charleston Harbor. A crew member handed her coolers filled with dismembered sea turtle parts.

The dredge crews were working around the clock, in shifts, digging the city’s port to 52 feet in depth, making it the America’s deepest. Completing a section of the $580 billion project could not be put off until fall; the crews needed to press on, one official

told her. The South was having a cargo boom and sea turtles were taking a hit.

“That was the worst day,” said Pate, DNR’s sea turtle conservation program coordinator.

Five endangered sea turtles were killed by port dredging in the 24-hour span, according to public records.

Pate’s department had already warned federal officials that something like this could happen.

The day before, Pate’s DNR colleague Lorianne Riggin notified staff at the Army Corps of Engineers, which manages dredging projects, that the first sea turtle nest of the season had just been found in Charleston County.

DNR scientists have known since the 1990s that, for the Charleston area specifically, the nesting turtles arrive in abundance once water temperatures hit about 61 degrees Fahrenheit.

In a series of emails obtained by The Post and Courier through a Freedom of Information Act request, Army Corps officials repeatedly — but reluctantly — invoked their right to legally dredge until Apr. 30 and, if needed, into May 31 that year.

“Granting an additional dredge extension until mid-May is certainly not an ideal scenario, but we are kind of stuck between the proverbial ‘rock and a hard place’ with this,” wrote Alan Shirey, an environmental engineer for the Army Corp’s Charleston District, 10 days before the deadly incident.

For decades, the Corps and DNR had an understanding — what Pate called a “gentlemen’s agreement” — that all dredging stopped on Mar. 31 out of concern for turtles.

And the Charleston District of the Corps mostly stuck to that agreement. But, in spring 2021, they opted to proceed with the dredging though the waters at the Charleston Harbor’s entrance measured 73 degrees that day, well above that 61-degree threshold.

Analysis of the Army Corp’s data by The Post and Courier shows that, since 2016, over 68 percent of dredge-related turtle deaths on the East Coast took place when water surface temperature was equal or above 61 degrees.

Both the Army Corps and S.C. Ports Authority said the port-deepening work was critical to handling large container ships that call on Charleston. Multiple methods were used to reduce the risk to turtles, from underwater “tickler chains” used to scare away marine life to physically netting and relocating turtles with shrimp trawls.

Had the Charleston project not used the hopper dredge, said Shirey, Charleston’s expensive port deepening project would have taken longer and cost much more: “We’re talking about tax dollars.”

But Pate and Georgia-based sea turtle biologist Mark Dodd see Charleston’s May 2021 incident as a glimpse of what’s to come as long-standing policies and agreements that once protected turtles begin to unravel.

Across America, battles between growth and conservation are being played out on many fronts. What stands out in this case is that, for decades, the two sides worked harmoniously under compromise.

But that co-existence is starting to erode as economic needs are putting increasing pressure on turtles, at a time when they are most vulnerable.

Seasonal dredging

Just months later, in the summer of 2021 te federal government determined that, even on paper, there would be no more limits to when the Army Corp could dredge Southern ports.

A biological assessment released a year earlier had predicted that dredging in the warmer months would kill 460 sea turtles across four Southeastern states — from the Carolinas though Georgia and Florida — over a period of three years. Still, it concluded, those deaths would not impact the endangered species’ “likelihood of survival.”

The Associated Press at the time reported that the change was motivated by both environmental and economic reasons.

The lure of bigger ships had led to port deepening in Charleston; Brunswick, Ga.; Jacksonville, Fla.; and elsewhere.

The Panama Canal’s expansion was a driving force behind a slew of harbor deepenings that pitted America’s port cities against one another in a race to grow. Today, at 52 feet, ships carrying 16,000 or more 20-foot cargo containers can now call on Charleston’s port at any time, regardless of the tide. The Army Corps says it will perform ongoing maintenance dredging in different cycles to keep it that way.

The waterway is wide enough to accommodate two of the supersized vessels side by side, the kinds once dubbed “post-Panamax” because they were too large to fit through the world-famous canal prior to expansion. In 2022, the Charleston’s port experienced the largest annual cargo growth of any major U.S. seaport since 2010.

S.C. Ports Authority CEO Barbara Melvin said in a Jan. 12 statement that the Army Corps assesses the environmental, economic and engineering aspects of a project before greenlighting a harbor deepening project. And the financial benefits of the port are clear, she said, supporting 1 in 9 South Carolina jobs, directly or indirectly, and generating more than $86 billion in economic output.

“This depth makes us more competitive,” she said in December 2022 when the Charleston project wrapped.

“This depth attracts more investment and business to our state. Most importantly, our deepening project will bring economic successes and opportunities to South Carolinians for generations to come.”

Dredges have always killed turtles. Hopper dredges, specifically, do a type of sediment sucking that can’t be made kill-free. However, science backed measures have kept annual deaths somewhat low for two decades.

Concerns about endangered sea turtles and the South’s port dredging date back to the 1980s. For decades, state biologists knew that female turtles returned every April to nest on beaches and sought out deeper holes in the nearby seabed. For a sea turtle, a shipping channel is a cozy place for rest. Taking a snooze puts it in the direct path of sediment suckers with rotating blades at the end.

Dodd, the biologist, explained it like this while serving as an expert witness on hopper dredges in Georgia’s district court: “It operates like a large vacuum cleaner, essentially. Turtles are sucked up in the dredge. They go up the pipes. And there’s a large impeller … it’s like a boat propeller … they usually get chopped up there.”

In 1991, trained observers were placed on dredges for the first time to tally up the maimed sea turtles. The numbers were so high, according to Dodd, that “almost immediately” the federal government took action.

Things became more transparent.

Today, anyone can log onto a website maintained by the Army Corps of Engineers and see how many endangered turtles and sturgeon have been killed by hopper dredging and where it occurred.

That’s also when the National Marine Fisheries Service, working under the Department of Commerce, developed a new policy: dredging windows in four Southern states. For almost 30 years, restricting dredge activity to times when coastal waters are colder — roughly winter months, but it varies state to state — was uncontroversial.

And, from a conservation standpoint, the policy was wildly effective at reducing deaths.

In Georgia, for example, the average number of turtles killed by dredges went down to about two. And it stayed that low, consistently, from 1994 until 2020. Conservationists say the most fragile species, like the loggerhead turtles, needed this reprieve to begin their rebound.

Then, with little warning, the dredge windows went away.

The ‘cheapest’ dredge

Dodd is a veteran wildlife biologist for the Georgia Department of Natural Resources who, like Pate, coordinates the state’s sea turtle program.

Part of his job is documenting the dead. For decades, most of that work involved picking up carcasses that came in with the tide.

In recent years, he’s been boarding industrial dredge fleets in Brunswick and Savannah to find dead turtles.

Sometimes he goes aboard just to see how the machinery is working and try to understand a growing problem.

“I’ve been on every dredge in the fleet,” Dodd told a U.S. District Court judge in 2021 during a testimony that he gave as part of a lawsuit over dredging and sea turtle deaths. The complaint was filed by a Georgia environmental group in 2021 soon after advocates realized that the Army Corp’s long-standing policy of winter-only dredging was getting sidelined.

The slow creep into warm weather dredging started in 2009. The Army Corps requested to dredge Savannah Harbor and Brunswick Harbor during summer months.

But that project stopped before it was completed. The sea turtle death toll had passed the legal limit, triggering a pause under the Endangered Species Act.

The number of deaths, or “takes” as the act calls them, was eight times higher, on average, that year. “That was considered unacceptably high,” said Dodd, in his testimony.

Under the law, the federal government can allow the incidental “take” of some endangered animals, with the right permits and prior assessment. A “take” encompasses many harmful impacts, including death, displacement and harassment.

When it comes to dredges and sea turtles, almost every “take” is a lethal one.

He said in court that he saw those turtles up close that were injured by the equipment.

He noticed that one species was getting hit hard.

And his department identified hopper dredges as a “major threat” to endangered loggerhead sea turtles, stunting the population’s ability to recover.

Loggerheads need 30 years to reach reproductive age, much longer than other species.

Only a few survive that journey, from hatchling to mom. And it was these super moms that were mostly being sucked up into the machines.

The hoppers move relatively quickly, compared to other dredges used for deepening.

Pipeline and hydraulic dredges are some of the slower alternatives. When it comes to turtles, hoppers have the reputation as being the deadliest.

They can also kill other long-lived species of concern, like the endangered Atlantic sturgeon — an iconic fish that can live 60 years and weigh 800 pounds, or nearly as much as a horse.

Horseshoe crabs also are commonly sucked in and crunched in the hopper’s machinery.

Over 9,000 of them died during Charleston Harbor’s most recent deepening.

“They’re also just the cheapest … and the most efficient,” said Megan Huyhn, an Atlanta-based attorney for the Southern Environmental Law Center. She filed a lawsuit on behalf of One Hundred Miles, an Georgia-based environment group when the Army Corps tried to dredge Brunswick Harbor in August 2022.

“We wanted a comprehensive review of the real impacts in warmer months,” she added.

In an eleventh hour move, the Corps paused the summer project. The following spring, the Georgia group celebrated another win when the Army Corps volunteered to conduct a more rigorous review of the environmental summer and spring dredging in Georgia. Last May, the group dropped the suit and, in the mean time, the former turtle-protecting dredge restrictions remain.

Just nine month earlier, environmental groups in North Carolina won a similar law-suit. They, too, successfully challenged the disappearance of winter-only dredging policies.

In South Carolina, however, the Army Corps’ slow embrace of warmer weather dredging has taken root.

Unlike Georgia and North Carolina, there are no pending agreements or lawsuits preventing the Palmetto State from warm weather dredging.

“Yes, historically, we have maintained a self-imposed dredging window (in South Carolina),” said Shirey, the Corp’s environmental engineer.

“Going forward, we may look to dredge outside our traditional window.”

Shirey said the Army Corps can lean on other science-based methods to reduce turtle deaths. He pointed to evidence that more intense relocation trawling done prior to dredging scoops up turtles that are in harms way and relocates them to safety.

Pate, the biologist, isn’t sure a measure like this could provide turtles the same protections as the traditional dredge windows. “The ocean is also getting warmer earlier than it had before,” she said.

The larger toll

Sea turtles are nesting earlier in the S.C. and other parts of the Southeast as climate change take hold. Scientists suspect that could be contributing to small upticks in turtles deaths.

The bustling harbors in South Carolina, Georgia and Florida have witnessed a particularly significant concentration of dredging projects leading to the deaths of multiple turtles. An expansion project in Savannah Harbor resulted in 24 fatalities from 2015 to 2018, marking the highest number of incidents among all projects, even with dredge windows in place.

The project in Charleston, which startled Pate in the middle of the night, caused 13 deaths within three years.

The project exceeded its allowable take limit for green sea turtles early on, in January 2019. Army Corps was allowed to continue dredging and requested a revised take permit, which they received, two years later.

Pate’s documentation of five deaths in one day, which occurred during the project, was described in court by Dodd when he was subpoenaed a few weeks later in the neighboring state. Charleston was used as a warning of what could occur is Georgia’s dredging windows were lifted again, as they just had been in South Carolina.

He said the event also demonstrates how Army Corps’ data takes may be underestimating the true toll.

The Army Corps’ data says five endangered turtles died in the Charleston hopper dredge on May 6, 2021. But biologists think as many as seven turtles died that day. The grisly nature of the dismembering machinery makes it difficult to puzzle together a single sea turtle body from the sludge of each dredge load.

The turtles often “get chopped into pieces,” making it a challenge for biologists to determine just how many of the creatures are there, Dodd said.

In other words, the observed number of turtle takes — what the trained observer writes on a clipboard — isn’t always the same as the actual deaths that took place.

That’s what makes it so hard to interpret all the data that the Army Corps posts on its website.

After years of hovering around 30 takes per year, the sea turtle annual death toll is ticking up. The vast majority were done with hopper dredges.

Dodd estimates that there are only about a dozen of these hopper dredges in the eastern U.S., and states compete with each other to contract them within the same narrow timeframe.

Year-round dredging policies eliminate those constraints and ongoing issues with project delays.

In the past, Georgia’s ports have used the slower alternatives to deepen the port of Brunswick, both pipeline dredges and hydraulic dredges.

Dodd was asked about these others dredge type during his testimony. Did they have the same deadly impact as hopper dredges had on sea turtles? “No,” the biologist said flatly. For the other dredges, his team hasn’t documented a single death.

Follow Clare Fieseler on Twitter @clarefieseler.