Altamaha exhibit

THE ALTAMAHA RIVER BEGINNINGS The Altamaha River, whose beginnings emerge from the foothills of Appalachia and course through the Piedmont and Coastal Plain to the Atlantic Ocean, is a river of slow, ancient, quiet and verdant character; a dream-like passage through time and habitats of dramatic scale.

IN THESE PHOTOGRAPHS

by James Holland, the river and our experience there comes alive in detail, from the tiniest microrganisms to the the grandest cypress and tupelo trees whose sizes Giant bald cypresses of the Altamaha River

humble the respectful visitor.

IN THESE WATERS thrive myriad flora and fauna that have sustained humans for thousands of years, providing energy, sustenance, and breeding grounds for the marshes and oceans that nourish life on our planet.

The Altamaha is one of the most ecologically diverse river systems in the world. Its main stem hosts some of the rarest plants and animals in the United States. Included among these are the spinymussel and the largest population of the endangered shortnose sturgeon south of Cape Hatteras, North Carolina. Dicerandra radfordiana (a pink-flowering annual mint), which has less than three hundred known plants on earth, is part of this most valuable basin. —James Holland

Diceranda radfordiana is found only on the unique sand ridges of the Altamaha River

THE ALTAMAHA’S BOTTOM LAND The Altamaha’s main course lies entirely

Many varied habitats compose the Altamaha’s basin, which is approximately 14,000 square miles, representing more than one-quarter of the state of Georgia.

within the Coastal Plain, the gently sloping area between the Piedmont and the coast.

Dropping only 90 vertical feet in its 137 miles, the Altamaha River seems deliberate and patient as it slowly widens on its path to the Atlantic Ocean.

While Native Americans inhabited the entire basin for thousands of years, European explorers of the sixteenth century and later settlers in the eighteenth century discovered the river as they traveled inland.

The Anglo-Americans who ventured upstream found not only sustenance in the native fish, mammals and waterfowl, but timber and bottomland that could supply them with resources to serve expanding markets back in Europe and around the globe.

Many familiar species of mammals and birds live in the bottomland along the Altamaha and its tributaries, but a surprising number of rare and unusual species also call this place home.

Bottomland refers to the low-lying land along the river which floods occasionally. Floods enrich the soil, making it attractive as farmland once it is cleared.

ALTAMAHA’S SHADED BLUFFS Shaded bluffs along the Altamaha River are home for a wide variety of plants and animals. These protected areas offer safe haven for numerous song birds, wading birds, and birds of prey as well.

These bluffs are higher land along the river, where well-drained soils support plants and animals that prefer to be out of the water.

Squirrels, opossums and raccoons are often seen foraging, and birds, such as tanagers, enjoy the shielding tree canopy.

SAND DUNES + SAND RIDGES Twenty thousand years ago, at the height of the last ice age, the Altamaha was bordered not by forests but by grasslands.

Prevailing winds sweeping from the west blew across exposed river sands and created 22,000 acres of dunes flanking the eastern side of the Altamaha, what we know today as the Ohoopee Dunes.

Going back even further in time is a series of sand ridges lying athwart the river.

As sea level has risen and fallen over the last 120,000 years, the old barrier islands are left behind to form terraces stair-stepping their way to the coast.

Bald cypresses are known to live more than one thousand years.

FRESHWATER WETLANDS + CYPRESS SWAMP Along the lower reaches of the Altamaha floodplain, the tide begins to make its presence felt, but not by making the water salty; the ocean is too far away and the volume of water the Altamaha discharges is too large. Instead, because freshwater is less dense than salt water, the Altamaha’s water rides on top of a wedge of salt water, rising and falling as the salt water moves upstream and downstream with each tidal cycle. Here the river forest is dominated by bald cypress and tupelo trees, which are better adapted than other kinds of trees to withstand long periods of inundation and saturated soils.

MEANDERS + OXBOW LAKES

Just as floods come and go, the very course of the Altamaha changes. Erosion and transport of sediment downstream causes the river to meander so extravagantly that the river eventually cuts through the base of each loop, thereby creating an oxbow lake.

Isolated from the rest of the river except during floods, these lakes are famous in the angling community for record largemouth bass and other game fish. They also provide important habitat for nongame fish, waterfowl, aquatic mammals such as otter and beaver, as well as a wide variety of reptiles and invertebrates.

BLACKWATER STREAMS Small, slow-moving rivers and creeks originating wholly in the Coastal Plain augment the Altamaha’s flow to the sea. Their waters are stained brown with tannic acids released from decaying vegetation in the heavily forested areas they drain. Beneath waters dark as iced tea, the rivers support unusual fish species. Along the banks, swamp forests support a vast array of resident and migratory birds, including spectacular swallowtailed kites.

Fish species who prefer blackwater streams include:

Eastern silvery minnow American eel Mud sunfish Sailfin shiner Sawcheek darter

FRESHWATER MARSHES On the lower Altamaha River, where the cypress and tupelo trees cannot tolerate constant flooding, the forest gives way to tidally-influenced freshwater marshes dominated by grasses, sedges, rushes, cattails, and even native wild rice.

When you reach the tidal range, the Altamaha becomes a totally different river.

Everything changes, even the fish species. The freshwater marshes mark the beginning of a most unusual change in ecosystems and are a gift that only nature could provide. —James Holland

ALTAMAHA’S SALT MARSH The coastal salt marsh, with its sweeping vista dominated by the salt-tolerant cordgrass Spartina alterniflora, is among the most biologically productive ecosystems in the world, surpassing even the tropical rainforest.

This complex foodweb supports organisms from those small enough to live between sand grains all the way up to large mammals such as dolphins and manatees. Humans also value the marsh for its role as a nursery for commercially important seafood species including shrimp, crabs, and a wide variety of fish.

Two of Georgia’s most innovative environmental laws, the Marshlands Protection Act of 1970 and the Shore Protection Act of 1981, not only set the pace for the protection of the Altamaha’s salt marsh and seashore, but also have served as a model for laws elsewhere in the United States.