Marsh Periwinkle Habitat for Many Species of and JOURNEY THROUGH Fishes, and Other Animals, Such

NATURALIST’S NOTEBOOK Moving Through the Marsh BY REBECCA NAGY • NORTH CAROLINA’S AMAZING COAST ILLUSTRATIONS BY CHARLOTTE INGRAM COLD OUTSIDE? in and out. They also provide THEPRETEND IT’S SUMMER MARSHMarsh Periwinkle habitat for many species of AND JOURNEY THROUGH fishes, and other animals, such A COASTAL SALT MARSH. Common to North Carolina’s as the marsh periwinkle. LEARN ABOUT THIS salt marshes, the marsh • Smooth cordgrass, periwinkle is no flower HABITAT NOW AND but instead is a or Spartina alterniflora, is the member of a group BE THAT MUCH MORE of marine gastropod predominant plant in North mollusks that are KNOWLEDGEABLE WHEN characterized by Carolina’s salt marshes. This their conical, THE WARMER WEATHER spiraling shells. salt-tolerant plant makes ROLLS AROUND. At low tide these snails the marsh look like a “sea of can be found at the base of The salt marsh is a fascinating one of their favorite foods, the grass.” The plant can grow as smooth cordgrass, Spartina habitat teeming with creatures alterniflora, which is the tall as 8 feet. At high tide, the predominant plant in big and small. These plants and North Carolina marshes. marsh periwinkle sneaks up the animals depend on — and thrive However, as the tide rises, so does base of the smooth cordgrass the periwinkle. Up the cordgrass stalk it in — the mixture of salt and fresh goes, where in turn, it sometimes becomes toward the top to escape rising food for sharp-eyed egrets and herons. water that continually flows in and water, and predators such as out of the area. shore birds and blue crabs. This habitat extends hundreds Marsh Periwinkle Littoraria irrorata • Named for the bright of miles along the blue coloring intertidal shore of on its claws sounds, estuaries, Smooth Cordgrass Blue Crab and legs, the If you’ve seen North Carolina’s creeks and rivers. With bright blue blue crab salt marshes, you’ve seen coloring along its frontal cordgrass. It is the pre- Water can range area, it’s obvious where this is actually dominant plant in the common North Carolina magnificent “sea of grass” crab gets its name. Like from very salty that grows between North olive-green other members of the Carolina’s barrier islands Decapod order, it has to almost fresh, and the mainland. Its on much of five pairs of legs. The importance to the marsh first pair is a set of cannot be overstated. depending on powerful claws, and its body. You Cordgrass filters heavy the last is flattened metals and toxins from into a paddle-like shape tides, rainfall and the water. It provides habitat can spot this for swimming. As a for numerous species of fishes and hunter, particularly of other factors. In shellfish, and gives refuge to waterfowl species’ five oysters and hard clams, and shorebirds. Its matted roots it is ferocious, and as the stabilize the soil and, literally, hold North Carolina, hunted, it makes ferociously pairs of legs the marsh together. Where tides bathe good eatin’. Whether prepared it in rich nutrients, it can reach a as freshly made crab cakes or marshes occur height of 8 feet. Higher in the as it scuttles left whole in their soft-shell marsh, it may only grow to a foot or so. stage, blue crab is a highlight between North Regardless of size, cordgrass is the indispensable around the of coastal cuisine. Carolina’s barrier thread in the marsh’s web of natural wonders. waters along islands and the Smooth Cordgrass Spartina alterniflora Blue Crab Callinectes sapidus the Atlantic mainland. Coast. The To live in a marsh, plants and animals need to adapt to first pair is a set of powerful claws, and the last is flattened into these constantly changing conditions. This community is one of a paddle-like shape for swimming. Its eyes are on the ends of nature’s most self-sustaining ecological systems and is a valuable movable stalks that allow the crab to see all around. The crab coastal resource. also can retract its eyes into grooves on its shell when danger • Marsh periwinkles, or Littoraria irrorata, are one of the is present. most prominent inhabitants of the salt marsh. This acorn-sized These scrappy crustaceans can withstand almost anything gastropod, also known as marsh snail, has a spiral shell and that nature throws at them. Crabs can live in areas with high an orange stripe on one side of the shell opening. The marsh salinities, such as the open ocean, or in areas of fresh water. periwinkle uses its radula, a tongue-like structure with up to 300 They even can grow back a leg if it is lost in a fight with another rows of teeth, to scrape up algae that grow on grasses, rocks, crab. A blue crab can make a feast out of dead animals or go on shells and the marsh floor. At low tide, this snail spends its time at the hunt. the base of plants in the salt marsh. Blue crabs offer a tasty meal for humans, gulls, herons and Marsh plants filter metals and toxins from water as it flows many species of fishes. Should its intended prey, the periwinkle, 36 coastwatch | winter 2015 | www.ncseagrant.org NATURALIST’S NOTEBOOK escape to During the tops of Marsh Mud Fiddler Crab the late 19th Why does the marsh, well . The male fiddler crab has one the smooth smell? Because marsh mud claw that is much larger than and early 20th is a thick nutrient soup that the other. He often holds this cordgrass, the transforms the carbon in giant claw out in front of his centuries, dead plants into energy to body as if it were a violin. blue crab can power higher forms of But he is more likely to use Egretta thula was life, including us. Any it for dance, percussion, or turn its attention good soup has a strong combat than to play a quick hunted almost aroma. Bacteria in the reel. Each species has mud break down plant distinct courtship gestures to oysters and debris and in doing so that involve waving and to extinction. emit a sulfurous compound snapping the big claw or even hard clams in the (H2S) that gives the marsh its thumping it on the ground. Their long and characteristic odor. In turn, these If vying for a mate, males THE MARSH bacteria are eaten by larger but still tiny engage in a sort of claw- marsh mud. fluffy plumes forms of life, such as plankton, which are wrestling to settle the matter. then eaten by fishes, shrimp, and other North Carolina has three • Marsh creatures that we might eventually species — the marsh, sand, were a popular consume. The marsh teems with and red-jointed fiddlers. They mud, with its creatures along this food chain. vary in size from ¾ of an inch addition to It replenishes North Carolina’s to just over 1½ inches and strong odor, plays coastal waters with rich and varied life. live in holes in the marsh women’s hats. So next time you get a whiff, don’t between high and low water. an important complain — just think, “Soup’s on.” The habitat role in this Marsh Mud Mud Fiddler Crab Uca pugnax of the snowy habitat. This egrets made thick nutrient them easy soup helps to replenish North Snowy Egret targets — they nest in large Carolina’s coastal waters. Bacteria colonies in shrubs a few feet in the mud break down plant During the late 19th off the ground. The species debris — while emitting a sulfurous and early 20th century, population has come back due snowy egrets were compound that gives the marsh hunted nearly to in large part to the Migratory extinction for their that certain smell. These bacteria long and fluffy white Bird Treaty Act of 1918, one plumes, which were are then eaten by slightly larger a popular accessory of the United States’ earliest for ladies’ hats. The species, such as zooplankton. birds made easy environmental laws. Fishes, shrimp and other creatures targets, conveniently The snowy egret is easily nesting in large colonies then eat the zooplankton. among shrubs just a few feet off identified by the coloration the ground. Today their populations • The mud also is home to have rebounded, thanks in large part of its feet and bill. It has black to the Migratory Bird Treaty Act of 1918, marsh creatures, including fiddler one of our nation’s earliest environmental legs, yellow feet, and a black crabs that live in dime-sized holes laws. These wading birds nest and forage near beak. The great egret has black the brackish waters of coastal barrier islands. in the muddy soil that are covered Clever hunters, they scrape their bright yellow legs, black feet, and a yellow feet along the marsh bottom to stir up prey and by water at high tide and exposed spread one wing over the water to reduce glare. bill. Snowy egrets nest in large to the elements at low tide. colonies with other long-legged Their burrows aerate the Snowy Egret Egretta thula birds, such as egrets, herons marsh mud during low tide and act and ibises. as an irrigation system during high tide. Fiddler crabs make their homes by digging sand and mud READ out of the ground, forming them into pellets, and depositing them Information for this article was gathered from North Carolina’s outside of the burrow. Amazing Coast: Natural Wonders from Alligators to Zoeasby David North Carolina has three species of fiddlers — marsh, sand Bryant, George Davidson, Terri Kirby Hathaway and Kathleen and red-jointed.

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