Georgia’s coast is almost as fertile as a tropical rainforest—and almost as threatened

Rising sea levels and increased coastal population are among the dangers to the ecosystem
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On a glorious May morning, I’m one of a dozen birdwatchers on a pontoon boat anchored in the mouth of the Altamaha River midway along Georgia’s coast. We are witnessing a sexual frenzy: On a sandy bank of uninhabited Egg Island, scores of squirming male horseshoe crabs are each in a mad scramble to latch onto a female and fertilize her clusters of tiny green eggs as she lays them in the sand.

Suddenly another riot erupts, this one driven by pure gluttony. Swirling flocks of ravenous shorebirds—red knots, dunlins, plovers, sandpipers, dowitchers, sanderlings, turnstones, whimbrels—descend into the jostling crabs and start gobbling up millions of eggs almost as fast as they are laid. So voracious are the gorging birds that they pay no heed to one another, even when they are accidentally pecked.

Illustration by Grace Lee/The Jacky Winter Group
Illustration by Grace Lee/The Jacky Winter Group

The eggs are a vital energy source for flocks journeying from winter homes as far south as Argentina to summer nesting grounds as far north as the Arctic Circle. Scientists believe that shorebirds time their migrations to coincide with horseshoe crab spawning in May and June. Georgia’s coast is a stopover for thousands of these travelers, whose feeding restores body fat to fuel the rest of their trek.

This spring ritual is only one example of nature’s remarkable munificence along our state’s 100-mile-long shoreline. Among ecosystems, Georgia’s coast ranks near tropical rainforests in fertility and productivity. Its nine major estuaries (or sounds), 14 barrier islands, and some 400,000 acres of salt marsh—a third of all salt marsh along the entire Atlantic coast—connect to the ocean and each other, like a great, benevolent being that gives sustenance and refuge to untold numbers of creatures: shrimp, blue crabs, clams, oysters, all manner of finfish, birds, and other species.

The pulsing heart of this great ecosystem is the tides. Twice-a-day surges of six to nine feet in height—the highest in the Southeast—push saltwater into the estuaries around the barrier islands, where it mixes with fresh water flowing from the mighty rivers: Altamaha, Savannah, Ogeechee, Satilla. The confluence traps sediments and nutrients, which make their way into salt marshes via winding tidal creeks and fertilize lush swards of Spartina alterniflora (cordgrass). Like vast, neatly mowed lawns, the meadows stretch for miles to the horizon.

The cane-like, salt-tolerant Spartina is the base of our coastal food webs. Georgia’s salt marshes yield nearly 20 tons of biomass per acre—four times more than the most carefully cultivated farmland—supporting nurseries for some 75 to 80 percent of the shrimp, blue crabs, and other economically important fish and shellfish species found along the Southeast coast. The waving fields of grass also shelter the young from predators.

But the marshes’ services don’t end there. They protect the mainland from storm surges, filter out pollutants, and maintain the physical integrity of the barrier islands. The sweeping marshes, broad estuaries, tidal rivers, and islands with their maritime forests and wide, sandy, unspoiled beaches make up a landscape of unsurpassed beauty.

In a sense, Georgia’s coast is lucky, perhaps unique. All but three of its barrier islands—Tybee, St. Simons, and Sea Island—are preserved through public and private initiatives. The pioneering Coastal Marshlands Protection Act, passed in 1970, has been remarkably effective in safeguarding the salt marshes. It requires developers who want to dredge, fill, or build in the marshes to obtain state permits and assess environmental impacts.

But though the law remains strong, it faces legal challenges and other threats to accommodate growing numbers of residents and developers. A 2006 Georgia Tech study calculated that the population of Georgia’s 10-county coastal region leaped by 62 percent to more than 558,000 residents between 1970 and 2000; it projected another 51 percent increase to about 844,000 by 2030. Environmental experts say the forecast is right on target.

“There’s a tidal wave of growth headed straight for Georgia’s coast,” warns David Pope, director of the Southern Environmental Law Center’s Atlanta office.

Contributing to the threat are poor coastal zoning and lax enforcement of environmental laws. On Earth Day last spring, in a surprise move that left environmentalists incensed and bewildered, Judson Turner, director of the state Environmental Protection Division, stripped the requirement for a 25-foot vegetative buffer intended to protect salt marshes. He said the rule was difficult to enforce and caused considerable confusion.

The case landed in the Georgia Court of Appeals, which ruled that state law mandates all waters, including salt marshes, have a 25-foot buffer. Turner, however, told EPD field officers to ignore the ruling.

Environmentalists took their plight to the 2015 General Assembly, where a bill to restore the marsh buffer was passed and was awaiting the governor’s signature as of this writing. Supporters were divided over an earlier version with developer-inspired amendments but were generally pleased with the final outcome.

Unfortunately, that close call was not the end of the coast’s problems. Scientists predict that rising sea levels from global warming will permanently submerge sizable swaths of the coast within the next 85 years. The accelerating pace of oil exploration also poses a danger.

Still, there’s hope. Earlier this year, county officials imposed a 90-day moratorium on new residential subdivisions on St. Simons Island. Also, a new, well-heeled organization called 100 Miles is working to “preserve, protect, and enhance” Georgia’s coast. More people, including government and corporate leaders, seem keenly aware that Georgia’s coast is a priceless resource. Protecting it will ensure that future generations can still marvel at wonders such as hordes of horseshoe crabs laying eggs that help migrating birds complete their amazing journeys.

Back to Secrets of the Georgia Coast

This article originally appeared in our May 2015 issue.

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