Welcome to the Estuary!

RiverVenture needs your help!

Use what you've learned to answer the following ten questions.

RiverVenture Headquarters has heard reports of problems in the estuary. A sign warns people not to collect or eat shellfish such as oysters and clams. People are testing the water for strange reasons...

  • Find out why the shellfish bed in this area has been closed.
  • What are other potential problems for the estuary?
  • Gather clues and file a River Wrap report when you're ready!

The panorama is full of objects, some obvious and others hidden. Scroll over the landscape and see how many you can find!

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Tidal Creek

"Winding Waterways"

Tidal creeks flow gently through the Spartina grass, the predominant plant of the salt marsh. From a distance, the wandering creeks of the salt marsh hide a habitat rich in diversity. Large oyster beds are revealed as tidal waters recede. Raccoons hunt the creek banks for fiddler crabs that dart in and out of muddy holes. And underwater, fish, shrimp, and crabs begin their lives in the safety of the tidal creek.

The tidal creek is a nursery for many larval and juvenile marine organisms. The tidal creek's small mud-dwelling worms and invertebrates provide a plentiful food source for fish. Shallow water and flooded Spartina grass protect growing organisms from larger, open water predators. Eventually, many of the more mature organisms will travel down the creek to live in deeper water of the estuary or open ocean.

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SCDNR

Tidal Creek

SCDNR

Tidal Creek

Clue:

Scientists are concerned about growing urban and suburban areas near tidal creeks and salt marshes.

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Live Oak

"A Historic Tree"

Beautiful live oaks, covered in Spanish moss, are a common site in the coastal zone. In maritime forests, the live oak is the dominant tree because of its tolerance to salt spray. Live oaks are known for their age; several trees present today are known to be over a thousand years old.

One thousand years before the arrival of Columbus, the "Angel Oak" began its long life near Charleston. Today, at over 1400 years old, this live oak still stands vigil over the coastal zone. It is considered the oldest living thing east of the Mississippi.

During the colonial period, live oaks were important lumber trees. Shipbuilders cut curved pieces from the junction of the limb and trunk and used them as ribs in wooden ships. The live oak tree has been a favorite ornamental tree since the 1700s. Many of the live oaks you see today were planted by plantation owners who wanted to outline the roads that led to their estate.

Live oaks are medium-sized evergreen trees with wide-spreading branches and dark, slightly ridged bark. Like most leaves, the thick leaves of the tree are covered by a waxy substance called the cuticle; the cuticle helps a plant keep from losing too much water. There are also hairs on the leaf, which help to protect the leaves from the salty breezes that would kill most other trees.

During the winter, many animals find nourishment from the acorns of the live oak tree. Turkeys, gray squirrels, gray foxes, raccoons, several birds, and rabbits are known to eat the acorns. Larger mammals, such as the black bear, white-tailed deer and elk, also consume the acorns.

Scientific Name: Quercus virginiana
Size: up to 15 m (50 ft.)
Range: Virginia to Florida and westward to Mississippi
Life Span: up to thousands of years
Feeding Habits: photosynthetic

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SCDNR

Live Oak

Stephen Sheperd

Live Oak

Clue:

Live oaks are large trees that have complex root systems and a wide canopy. They are native to South Carolina and found primarily in the coastal zone.

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Cabbage Palmetto

"A State Symbol"

The cabbage palmetto belongs to the palm family (Arecaceace). This branchless evergreen tree grows to a height of over ten meters (33 feet) tall. The cabbage palmetto is found in coastal regions from North Carolina to Florida. The tree usually inhabits maritime forests, islands within salt and brackish marshes, and the edges of ponds. It is a commonly planted tree in urban areas throughout South Carolina.

The cabbage palmetto is prized as South Carolina's state tree. During the Revolutionary War, coastal forts were made of palmetto logs. Where cannon balls would shatter a harder tree, they lodged into the cabbage palmetto's soft wood. The trunks are used in the construction of docks since the wood is resistant to sea worms. Some people eat the tips of the main stem of the tree, and find that it tastes similar to a cabbage.

In July, the cabbage palmetto's fragrant flowers attract a variety of insects, bees, wasps, and ants that carry the pollen between flowers. Once pollinated, the flowers begin developing a pea-sized fruit. Animals, such as raccoons and birds, eat the fruit and spread the seeds. Some fruits are swept away by sea currents and are transported as far away as the North Carolina shores.

Scientific Name: Sabal palmetto
Size: up to 10 m (33 ft.) tall
Range: coastal areas of North Carolina to Florida
Life Span: hundreds of years
Feeding Habits: photosynthetic

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ETV

Cabbage Palmetto

ETV

Cabbage Palmetto

Clue:

Our state tree can be found throughout the coastal zone. Its durable and flexible wood helps to protect the coastline from hurricanes and strong winds.

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ETV

Cabbage Palmetto

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White-tailed Deer

"A Common Herbivore"

White-tailed deer can be found in every region of South Carolina, from the mountains to the sea. In the Coastal Zone, they can be seen feeding on the nuts of live oaks or grasses in the salt marsh. White-tailed deer are named for the underside of their tail, which can be seen as the deer flees from a stressful scene. Putting the tail up is believed to be a danger signal for other deer. Deer have a very good sense of smell; bodily scents reveal information about themselves to other deer. Deer eat soft vegetation such as grasses, nuts, fruits, mushrooms, algae, and mosses.

The antlers on the top of the male deer's head serve as a protective device. The healthier the deer, the healthier the antlers. Antlers begin showing after about two years of age, and mature antlers take about four months to grow. During the summer, the antlers are soft and velvety. By winter, the deer have rubbed off the velvet onto nearby trees, and the harder antler underneath begins to show through. The antlers usually fall off the deer during the winter. Once the antlers have fallen off, the process of antler growth will resume.

Despite hunting, deer still overpopulate many forests. Overpopulation results in social, reproductive, and nutritional conflicts that cause unhealthy deer. Also, the more deer there are in a certain population, the easier diseases are spread. Therefore, deer hunting is needed to keep populations healthy.

Scientific Name: Odocolleus virginianus
Size: about 1 m (3 ft.) tall, 2 m (6 ft.) long, around 60 kg (125 lbs.) in mass
Range: all of the United States excluding some areas in the far West
Life Span: 5 years
Feeding Habits: Herbivores

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USFW

White-tailed deer

USFW

White-tailed deer

USFW

White-tailed deer fawn

Clue:

As land along the salt marsh is developed, animals such as the white tailed deer are pushed out of their natural habitats. In order to keep their living and feeding areas clean, animals may use the marsh as waste areas. Animal wastes can add harmful bacteria to the water; the bacteria can be identified by a fecal coliform count.

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Raccoon

"A Masked Omnivore"

In marshes and the estuaries, raccoons can be seen feeding on crayfish, crabs, shellfish, reptiles, and the eggs of birds and reptiles. Fruits, nuts, and berries are also favorite foods. They are often seen cracking the hard outer covering of their prey on the rocks in the water to get to the tasty insides.

Raccoons have been known to wreak havoc on many reptile populations by eating all of the eggs. Raccoons sometimes "wash their food" in order to enhance their sense of touch making it easier to reject inedible material. As their natural habitat has become more urbanized, raccoons have taken to scavenging for whatever human leftovers they can find.

Raccoons are easily recognized by the "mask" they wear across their eyes and their ringed tail. They are omnivorous and have become scavengers in many urban areas.

The primary predators of raccoons include man, bobcats, and owls. Raccoons are often hunted and trapped for sport and food in South Carolina. They are known as pests because they sometimes destroy property, spread rabies, and decrease the populations of some endangered animals.

Scientific Name: Procyon lotor
Size: about 23 cm (9.5 in.) tall at the shoulder, 70-100 cm (28-38 in.) long, and 3-21 kg in mass (8-48 lbs.)
Distribution: throughout most of the United States and all the way down to South America excluding some mountainous areas and deserts
Life Span: about 3 years
Feeding Habits: Raccoons feed on small water animals like crayfish and mussels as well as on berries, fruits, and nuts.

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Corel

Raccoon

USFW

Raccoon

Clue:

Raccoons have adapted well to human development. They often feed and live around salt marsh areas and may increase the amount of fecal waste found in nearby waterways.

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Spartina (Smooth Cordgrass)

"A Sea of Grass"

The Coastal Zone is well known for a "sea of grass" that dominates its estuaries. Spartina, also known as cordgrass, is a perennial wetland grass that makes up much of the tidal salt marshes of the south. An acre of Spartina is more productive than an acre of wheat! The hardy plant's strong roots have to be able to resist salty floodings at high tides. In fact, if you look closely at a Spartina leaf, you will see crystals of salt that have traveled from its roots and out through the leaves.

Spartina is found in groups from Newfoundland to Florida and west to Texas. The salinity of salt marsh soil affects the growth of cordgrass; Spartina grows the tallest at the water's edge, and it grows shorter farther away from the water. The maximum height of the plant varies greatly, ranging from 20-150 centimeters tall (8 to 60 inches). Soil aeration, nutrient availability, and length of water exposure also influence spartina growth. In the fall, spartina begins to die. Once the Spartina is dead, bacteria will help to break it down into detritus. Detritus provides necessary nutrients to many animals in the salt marsh and estuary.

Spartina is an important food source for many birds. The seeds are eaten by marsh birds, songbirds, sharp-tailed sparrows and several species of migratory waterfowl. Geese wintering along the coast are known to eat the roots. Spartina also provides an important nursery and protective habitat for many juvenile crustaceans and fishes.

Scientific Name: Spartina alterniflora
Size: 20-150 cm (8-60 in.) tall
Range: Newfoundland to Florida and west to Texas
Life Span: about 3 years
Feeding Habits: photosynthetic

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USGS

Spartina (Smooth Cordgrass)

USC

Spartina (Smooth Cordgrass)

SCDNR

Tidal creek with spartina

Clue:

Without Spartina grass, the salt marsh ecosystem would collapse. Spartina marshes provide an important nursery habitat for fish, crabs, and other young animals. It protects the mainland from coastal flooding, and it protects barrier islands from erosion. Spartina traps sediment and pollutants that come from the mainland.

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NOAA

Detritus

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Snail (Marsh Periwinkle)

"Spartina Scavenger"

The periwinkle snail can be found grazing on live and dead spartina. The periwinkle snail is a mollusk and therefore related to clams and oysters. Snails have two pairs of tentacles on their head. The longer pair typically has light-sensitive eyespots while the shorter pair is used to feel and smell.

Snails are hermaphrodites, so they can fertilize their own eggs; however, the success rates of cross-fertilization are much greater. The snail's shell helps protect it from many predators, and the periwinkle also climbs up spartina grass stalks to get out of a predator's reach. Like most of the salt marsh organisms, the marsh periwinkle plays an important part in the salt marsh food web. They eat algae and detritus, while turtles, birds, crabs, and fish feed upon the marsh periwinkle.

Scientific Name: Littorina irrorata
Size: 2.5 cm (1 in.) in length
Distribution: the Atlantic coast of the United States
Life Span: about ten years
Feeding Habits: feed on algae and detritus

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SCDNR

Marsh Periwinkle

NOAA

Marsh Periwinkle

Clue:

The periwinkle snail is a mollusk that feeds on fungi living on spartina. It is believed that marshes are dying because the snail is overpopulating the marsh.

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USGS

Marsh Periwinkle

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Hard Clam

"A Seafood Delight"

Seafood lovers often comb the mud of the salt marsh looking to dig up hard clams. Hard clams sold in markets are called littlenecks, cherrystones, and chowders. The littleneck is the smallest and most expensive hard clam. Cherrystones are medium-sized, while chowders are the largest and least expensive. The chowders come from older and tougher clams and are often cut up to use in clam chowder.

Hard clams are filter feeders that pass water, rich in plankton, over their gills. Hard clams have two small tubes; the inhalant siphon sucks water in, while the exhalant siphon pushes water and wastes out. The inhalant and exhalant siphons function somewhat like a human's mouth and anus. Food particles in the form of plankton are removed and digested. If their particles are inedible, they are expelled through their inhalant siphon. Wastes from digested particles are expelled through their exhalant siphon in the form of fecal pellets. Like oysters, clams help to filter out contaminants from the water.

Scientific Name: Mercenaria mercenaria
Size: up to a width of about 10 cm (4 in.)
Distribution: along the United States Atlantic coast as well as the Gulf of Mexico
Life Span: about 30-50 years
Feeding Habits: filter feeders digesting plankton

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SCDNR

Hard clam

NOAA

Hard clam

Clue:

Clams and oysters are mollusks. Clams are filter feeders that live in a benthic habitat.

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Southern Flounder

"Find the Fish!"

Can you find this common estuarine fish? Flounder have the unique ability to blend in with the bottom of rivers, estuaries and the ocean. Dark spots and blotches on the top side of the fish act as camouflage. Its flat, saucer-like shape makes it appear as an innocent bulge on the floor of a river or ocean.

Special adaptations such as these allow the Southern flounder to ambush prey and hide from predators. Unsuspecting shrimp, mummichogs, spot, and mullet make up the flounder's diet. The Southern flounder can tolerate a wide salinity range and may inhabit ocean, estuary, brackish, and freshwater habitats.

As larval fish, the flounder have eyes on both sides of their head; during development, the eyes eventually migrate until both eyes are found on the topside of the fish. The underside of the fish, the "blind" side, is usually light in color.

Once the flounder begin to mature, they will leave the estuaries for offshore spawning grounds. After spawning the mature fish will reenter the estuaries. The larvae hatch in the spawning grounds, and are transported by tidal currents toward the shore and into an estuarine nursery habitat. In the shallow tidal creeks, the larvae feed on small shrimps and fishes. As they increase in size, fish become their preferred prey. Southern flounder remain in these creeks until they are about 20-25 centimeters (eight to ten inches) long. As adults, they are frequently found in shallow water near oyster reefs or the mouths of small rivulets.

Southern flounder are popular in both the commercial and sport industries; they are often caught by nighttime gigging in tidal creeks and marshes, as well as by hook and line.

Scientific Name: Paralichthys lethostigma
Size: up to 75 cm (30 in.)
Distribution: Chesapeake Bay to Florida, Gulf of Mexico
Life Span: about 3 years
Feeding Habits: grass shrimp, mummichogs, spot, and striped and white mullet

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SCDNR

Southern flounder

ETV

Southern flounder

Clue:

Juvenile and adult flounder live in the salt marsh. They are adapted to living on the substrate, or bottom of creeks and rivers in the marsh.

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SCDNR

Larval flounder

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Eastern Oyster

"Clean-up Crew"

Eastern oysters are one of the most common organisms seen living in and around salt marshes. They are also one of the most common organisms seen on the plates of seafood lovers! Oysters eat plankton by filtering the water and digesting the edible material. As the oyster filters for food, it also filters pollutants out of the water; however, these pollutants can build up in the oyster and are dangerous in large quantities. Oysters can pump up to190 liters (about 50 gallons) of water a day!

Oysters begin their lives as males and develop into females. Underneath the water, the younger males release their sperm, while the older female oysters release their eggs. The egg and sperm will meet outside the body; however, a female secretes millions of eggs in order to increase the survival rate. Twenty-four hours after fertilization, a swimming larval form of the Eastern oyster hatches. They are helpless against tidal currents, and like many larvae, they are considered plankton and are heavily preyed upon. In the last larval stage, the oyster crawls around using its foot, or muscular body, as it tries to find a hard surface to settle for the rest of its life. Many oysters do not survive because they fail to attach to a suitable surface. Larvae that do survive often have attached themselves to other oysters.

Attached to an oyster's gills are small hairs, known as cilia. These hairs help to sweep oxygen and food into the oyster as well as keep debris out. However, if an irritant like a piece of sand still enters the oyster, a mucous-like substance is created to cover the irritant to make it smoother and less irritating; after many layers of mucous, the grain of sand becomes a pearl.

Scientific Name: Crassostrea virginica
Size: about 10 cm (4 in.)
Distribution: along the east coast of the United States into the Gulf of Mexico
Life Span: about 20 years
Feeding Habits: filter feeders feeding on phytoplankton

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SCDNR

Eastern Oyster

SCDNR

Eastern Oyster

SCDNR

Eastern Oyster

Clue:

A single oyster can filter up to 190 liters (50 gallons) of water a day! The filtering action of oysters is important because it removes harmful bacteria and other contamin-ants in marine environments, But many contaminants remain in the tissues of oysters, making them dangerous for human consumption. The state monitors water quality and may prohibit the harvest of oysters if contamination is heavy.

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Green Porcelain Crab

"An Alien Visitor"

An alien visitor has landed on the coast of South Carolina! The green porcelain crab is a small, flattened crab that is native to West Africa, Brazil, and the Gulf of Mexico. The tiny crab has mysteriously found its way to South Carolina and its population is increasing rapidly.

There are many theories as to why the crab is in South Carolina's waters. They may have hitched a ride with seafood imported into South Carolina. Aquarium trade may also accidentally introduce a nonnative species into a new area, or the porcelain crab could have entered southeastern waters through ship ballast.

When a new species is introduced into an ecosystem, it can wreak havoc on the food web of native plants and animals. Nonnative species generally do not have natural predators when they are introduced into a new area.

Scientific Name: Petrolisthes armatus
Size: 2-6mm (less than 0.25 in.)
Range: coasts of West Africa, Brazil, Gulf of Mexico, and Southeastern U.S.
Feeding Habits: filter feeder of plankton and microscopic organisms

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SCDNR

Green Porcelain Crab

SCDNR

Green Porcelain Crab

Clue:

Recent studies determined the green porcelain crab is not yet a threat to native ecosystems. But the green porcelain crab, like the oyster, is a filter feeder and could potentially compete for food with native filter feeders if the population grew out of control.

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SCDNR

Range of Green Porcelain Crab

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Larval Red Drum

"A Nursery Habitat"

Young fish like the red drum are protected from predators by shallow tidal creeks flowing through the cordgrass. Red drum spend their first few months feeding on plankton in creeks. Once larvae have moved to deeper estuarine waters, they feed on crustaceans and small fishes. When water temperatures rise in the spring, small red drum reenter the tidal marsh creeks. There, they begin to grow rapidly while feeding on small fishes and crustaceans. In May and June, these fish again leave the small creeks for the open shallows of the estuary.

Adults are normally found in near-shore and coastal waters. The red drum, also called "channel bass" or "spottail bass," is a member of the drum family, Sciaenidae, and a close relative of Atlantic croaker, spot, and kingfish. Red drum are reddish-bronze with a distinct spot or spots at the base of the caudal fin. Scientists believe that the spot on the tail confuses predators into attacking the fish's tail instead of its head, giving the fish a better chance to escape.

Red drum males produce "drumming" sounds during the spawning season to attract females. Males undergo a color change during this time, becoming dark red or bluish gray on top with a pale underside.

The red drum's predators include man and dolphins. The red drum has been placed on lists of fish that have been fished into a state of decline. Red drum numbers in South Carolina have increased in recent years, but commercial fishing is still restricted.

Scientific Name: Sciaenops ocellatus
Size: up to 1.5 m (58 in.), mass: up to 41 kg (90 lbs.)
Range: Delaware to southern Florida
Life Span: up to 30 years
Feeding Habits: fish, small crabs, grass shrimp, and bottom dwelling organisms

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SCDNR

Larval red drum

Lee Fuiman

Larval red drum

Clue:

The salt marsh is an important nursery habitat for larval and juvenile red drum. While in their larval phases, red drum are protected by shallow tidal creeks and rivers.

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ETV

Adult red drum

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Larval Shrimp

"A Nursery Habitat"

Larval shrimp use tidal creeks and marshes of the estuary for food and shelter. There are many kinds of shrimp found in the salt marsh and estuary, including pink, white, and brown shrimp. As planktonic larvae, shrimp eat other zooplankton, and as adults they eat detritus, small marine worms, small fish, and microalgae. Shrimp have walking legs to help them move short distances, while their swimming legs help propel them longer distances. To escape predators, shrimp can use their abdominal muscles and other appendages to quickly move backwards.

White and brown shrimp primarily live upon a muddy bottom while the pink shrimp like a more sandy or shell-like bottom. In South Carolina, there are fewer pink shrimp than white or brown shrimp because South Carolina has primarily muddy-bottomed waters. Commercial shrimping is an important part of the economy of South Carolina.

Scientific Name:
White shrimp: Penaeus/Litopenaeus setiferus
Brown shrimp: Penaeus aztecus
or Farfantepenaeus aztecus
Pink shrimp: Farfantepenaeus duorarum
Size: up to 15 cm (6 in.)
Range: near-shore and inshore waters from Massachusetts to Mexico
Life Span: about 2 years
Feeding Habits: omnivores that will eat any available food

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USM

Larval shrimp

NOAA

White shrimp (mature)

SCDNR

Shrimp life cycle

Clue:

Larval planktonic shrimp use small salt marsh creeks as nursery grounds. Larval shrimp are heavily preyed upon by many marine animals.

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Larval Blue Crab

"A Nursery Habitat"

In the protected habitat of the salt marsh, fertilized blue crab eggs go through a series of developmental stages. As larvae, they feed upon zooplankton. Adult blue crabs eventually feed on small fish, other crustaceans (including other blue crabs), mollusks, and decaying animal and plant matter. Adults spend more of their time in the estuary. Red drum and humans are the primary predator of the blue crab.

During the summer, people line coastal creeks and rivers hoping to pull in blue crabs. Blue crabs tolerate a wide range of water conditions, and can be found in saltwater and fresh water. Their preference is usually for brackish water, a mixture of fresh and salt water that can be found in the salt marsh. Tidal water pushing upriver creates the perfect environment for the crab.

Like all arthropods, the blue crab has a hard exoskeleton for protection and support; however, the exoskeleton must be shed as the crab grows. Before the crab molts its hard outer shell, a new shell is being formed underneath the old one. By the time the old shell is molted, the new one is ready. The new shell will harden more over time. Soft-shell crabs are a prized seafood.

Scientific Name: Callinectes sapidus
Size: width: up to 23 cm (9 in.)
Range: coastal waters from Nova Scotia south to Argentina
Life Span: about 3 years
Feeding Habits: Larvae eat zooplankton, while adults eat larger prey including fish and decaying plant/animal matter.

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J Dineen

Blue crap (megalops)

SCDNR

Blue crab (zoea)

SCDNR

Blue crab (mature)

SCDNR

Life cycle of the blue crab

Clue:

Larval blue crabs grow in the relative safety of tidal creeks and streams.

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Benthic Organisms

"Stick in the Mud"

Benthic organisms, also known as benthos, are organisms that live on or in the mud at the bottom of salt marshes and estuaries. There are many types of benthos; marine worms, crustaceans, bi-valves, and snails are are a few of the benthic organisms. Typically areas with muddy bottoms contain more of the marine worms while sandier bottoms contain more of the crustaceans. Almost all of the benthos are heterotrophs.

The benthos that live on the surface of the mud are known as epifauna; the prefix "epi" means upon. Benthos that burrow into the mud are known as infauna. There are many types of marine worms found in the benthic zone. Most marine worms have segmented bodies and chaetae, or bristles, that are commonly found on their bodies. The chaetae help the organism move around in their environment. The oligochaete worms have few bristles; "oligo" means few. The polychaete worms have many bristles; "poly" means many. Most of the worms are deposit feeders; they ingest sediment, extract the nutrients, and release the inedible material back into the water or sediment.

Some other benthos are filter feeders and feed by straining small, free-floating plankton. Other benthic organisms graze upon the surface of the mud or feed upon smaller benthos.

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SCDNR

Infauna

SCDNR

Polychaete

SCDNR

Marine worm

Clue:

In a waterway, most chemical contaminants settle into the sediment on the bottom. Benthic organisms are good indicators of stresses on the environment from these chemical contaminants. The health of benthic organisms can also indicate other stressors such as salinity changes or low dissolved oxygen levels.

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SCDNR

Eastern oyster

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Ivory Barnacle

"Pier Groups"

Ivory barnacles are a widespread resident of the salt marsh. The ivory barnacle can be found on docks, piers, the hulls of ships, and on the shells of oysters. The ivory barnacle has a sedentary lifestyle. The hard shell surrounding the barnacle is formed during one of the larval stages. Once the barnacle goes through its two larval stages, it will find a suitable substrate to attach to.

The plates that make up the barnacle's body can move to expose its six pairs of featherlike legs, called cirri. Cirri filter plankton from the water for the barnacle to digest. Fertilization is internal. Barnacles are hermaphrodites; however, they rarely self-fertilize since offspring are more successful if they come from two parents.

Scientific Name: Balanus eburneus
Size: up to 3 cm (1.25 in.) in width
Distribution: Maine to South America
Life Span: 6-20 years
Feeding Habits: filter-feeder

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ETV

Ivory barnacles

Clue:

Ivory barnacles are a widespread resident of the salt marsh. The ivory barnacle is a filter-feeder.

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American Oystercatcher

"Oysters Beware!"

Oysters beware if the oystercatcher is near! Oystercatchers are large shorebirds that live on sandy or pebbly beaches, mudflats, and the borders of salt marshes. The American oystercatcher gets its name from its fondness for oysters. The bird uses its long bill to cut an oyster loose from its shell. The oystercatcher also eats other bivalves such as clams and mussels. Snails, barnacles, fiddler crabs, aquatic insects, and sea worms are part of its extended diet.

During breeding, oystercatchers are quite aggressive and make loud cries. Once the oystercatcher finds a mate, they remain mates forever. After mating, the birds nest and lay eggs. The males generally take care of the eggs during the day, while the females care for them at night. Young oystercatchers depend on their parents for food, which is uncommon among other shorebirds.

Oystercatchers were once hunted to near extinction along the Atlantic coast. Today, the total population of oystercatchers on the east coast is 3,500 birds. The oystercatcher's natural habitat is often threatened by coastal development and off-road vehicles. Their eggs are vulnerable to predators and can be washed away by storms and boat wakes. Today, oystercatchers are making a comeback in protected areas around South Carolina.

Scientific Name: Haematopus palliatus
Size: 43-53 cm (17-21 in.)
Distribution: widespread throughout coastal areas of North and South America
Life Span: evidence points to 15 - 20 years
Feeding Habits: carnivore; shellfish

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SCDNR

American Oystercatcher

ETV

American Oystercatcher

Clue:

In the salt marsh food web, the oyster is preyed upon by the oystercatcher. Man is the biggest threat to the oystercatcher. We threaten shellfish resources by developing on or near the oyster's natural habitat.

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NOAA

American Oystercatcher

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DHEC Sign

"Caution!"

People of South Carolina love their oysters and clams. The shellfish industry brings millions of dollars to the economy of South Carolina, and recreational oyster harvesting is a popular activity. But oyster beds are often closed due to unsanitary water. The biggest threats to the health of oyster beds are sewage, development, marinas, and runoff pollution. Because of the severe impact of runoff pollution, shellfish beds are automatically closed after heavy rainfall. Oil spills can also close shellfish beds.

In South Carolina, the Department of Health and Environmental Control (DHEC) monitors water quality to ensure shellfish are safe to eat. They also patrol shellfish areas to make sure people do not illegally harvest oysters from closed areas.

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DHEC

DHEC Sign

SCDNR

DHEC Sign

Clue:

DHEC monitors shellfish beds to make sure people do not eat diseased or poisoned shellfish.

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Shell Mound

"A Mysterious Mound"

Strange mounds of discarded oyster shells can be found throughout the coastal zone of South Carolina. Archaeologists believe some of these mounds date back 4,000 years! We know these shells were placed there by Native Americans, but archaeologists debate the purpose of these shell mounds.

Some archaeologists think the shell mounds served no purpose and were simply trash piles that built up near living areas. Others believe the mounds were monuments used in spiritual ceremonies. Mounds can be as large as 240 meters in diameter (800 feet) and four meters high (13 feet). Shell mounds in Charleston salt marshes tell us that Native Americans must have been eating shellfish for thousands of years!

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SCDNR

Shell Mound

Clue:

A local project encourages students and other groups to recycle old oyster shells from restaurants and oyster roasts. The shells are placed in areas where there are few shellfish. Larval oysters can then attach themselves to these shells, since they provide a hard, suitable substrate.

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DHEC Patrol Boat

"The Shellfish Beat"

If you dare to collect oysters from a closed bed, look over your shoulder... a law enforcement officer may be there to make sure you don't eat the contaminated mollusks! The Department of Health and Environmental Control (DHEC) is in charge of monitoring the health of shellfish waters and may close a bed if found unsafe.

There are many environmental factors that determine whether a shellfish bed should be closed to harvesting. Some factors, like heavy rainfall, are immediate indicators that an aquatic ecosystem may be at risk for runoff pollutants. Recent oil spills, marinas, and nearby development may also be taken into account when judging the health of the water.

Understanding how pollution can enter the water, and careful monitoring by means of water sampling, are important tools for protecting people from dangerously polluted areas. Sampling is done with a special instrument that collects water and measures several factors affecting the water's chemistry. Measurements from water samples may include temperature, pH level, dissolved oxygen (DO), salinity, and fecal coliform counts. A single abnormal factor, or collection of abnormal factors, may lead to the closing of a shellfish bed. Data from water samples may also be used to determine whether an area is fit for drinking, swimming, or fishing.

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DHEC Patrol Boat

DHEC

Shellfish Law Enforcement taking oyster samples

USFWS

Stream monitoring technicians taking water samples

DHEC

Shellfish Law Enforcement checking a harvester's load of oysters

Clue:

A water sample provides essential information on water quality. Healthy shellfish beds are classified as "Shellfish Harvesting Areas," or SFH. Let's sample this area of the harbor to determine why the shellfish bed is closed.

The sample revealed that:

- Dissolved Oxygen (DO) levels are normal for this area at 5 mg per liter.

- Salinity is average for estuarine shellfish at 25 grams of sea salt per liter.

Estuaries have fluctuating levels of salinity; other organisms may require different degrees of salinity.

- Temperature is 29 degrees Celsius (82.4 degrees Fahrenheit). It is summertime, so this is a safe temperature for shellfish.

- pH is 7.6, a good value for the estuary

- Turbidity levels meet the state standard established by DHEC

- Fecal coliform counts are too high at 300 hundred colonies per 100 ml. of water!

It appears our oyster bed was closed due to a high fecal coliform count.

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Industry

"The Dilution Solution"

An old saying goes, "the solution to pollution is dilution." Waterways are often used to dilute wastewater from industrial processes and sewage treatment. Nuclear and coal burning plants cool their machinery with river water. Textile and paper mills use rivers to dilute pollutants and other by-products.

Prior to its release back into the waterway, some waste water is decontaminated for safety. It is then released at a specific area, or "point," usually a pipe emptying into a river or stream where untreated pollutants can be monitored. Point source pollution is the name for pollution that can be traced to a specific point.

In South Carolina, the Department of Health and Environmental Control (DHEC) monitors pollutants so that they do not exceed what the river can handle. The Environmental Protection Agency monitors pollution from industry on a national level.

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Ed Ingram

Industry on Cooper River

EPA

Point source pollution

Clue:

Point source pollution can be traced to a particular point and monitored for safety; however, increasing levels of mercury are still being found in many rivers. People disagree as to the impact of point source pollutants.

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City of Charleston

"A Historic City"

The birth of the historic city of Charleston is tied to a unique coastal zone feature, the estuary. The Charleston harbor is an estuary, a place where the fresh water rivers, such as the Cooper River, meet the salt water of the ocean. Access to inland rivers and ocean trade routes made Charleston an ideal location for a seaport. Natural features of the estuary, such as marshes, dunes and barrier islands, protect the harbor from waves and hurricanes.

The area began to host trade ships from Europe as early as the 15th century. Goods soon traveled to and from inland locations on rivers that emptied into the harbor. Trade by sea eventually led to the founding of Charleston in 1680. In the 1700s, raw goods such as animal skins, rice, wood, indigo, and tobacco were popular exports. Imports such as textiles and luxury items came in from European locations. In the 18th and 19th century, Charleston also played a major role in the slave trade, both as an importer and slave market.

Above the estuary, coastal zone rivers became the setting of Charleston's first economic success, the rice plantation. The inland flush of tides was ideal for the cultivation of rice. Rice was difficult to cultivate, and rice planters relied on the labor of experienced slaves from West Africa. The tradition of growing rice was new to the colonies, but common in this area of Africa. Today, West African traditions and language known as "Gullah" are an important part of the coastal culture.

As South Carolina's oldest city, and one of the largest tourist attractions in America, Charleston is of incredible historic value to the country. In the 1700s, wealthy rice planters began building the grand homes and buildings of the city. During the plantation period, traditions of West African culture added to the state's growing personality. In 1718, the pirate Blackbeard sailed into the Charleston harbor and blockaded the city. During the Revolutionary War, the harbor was the scene of the first naval battle, and in 1861, the first shots of the Civil War were fired on Charleston's Fort Sumter. Tourism, a major seaport, and industry based on the river continue to fuel Charleston's economy.

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ETV

Charleston, South Carolina

ETV

Charleston, South Carolina

ETV

Lighthouse near Charleston, South Carolina

Clue:

Growing cities like Charleston can contaminate rivers with nonpoint source pollution, also called runoff pollution. Chemicals, nutrients, and bacteria from sewage and pet wastes find their way into rivers when rain sweeps over the land. Growing suburbs add to the problem.

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Port of Charleston

"An Important Seaport"

Freighters, some 10 stories tall, line the Cooper River. Trade by sea has always been an important part of South Carolina's economy. Today, the shipping industry brings billions of dollars into the state. The Port of Charleston is the largest container port in the southeast and one of the busiest in the United States. Cars, foodstuffs, forest products, and machinery are some of the many things loaded on and off container ships. A standard container can be delivered directly onto the backs of trucks or trains leaving for other places around the country.

Cranes that lift containers are amazing engineering feats. A single container crane can cost over six million dollars and have a mass of over 800 metric tons. Cranes are so important to the shipping trade that they are given names such as "Cranosaurus" and "Ichabod Crane." With over 2000 ships entering the port every year, moving containers and other cargo is an around-the-clock effort. In order to bring even more ships into the ports of Charleston, major projects to deepen the harbor and raise the height of the Cooper River Bridge are underway.

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ETV

Port of Charleston

ETV

Port of Charleston

Clue:

To balance a top-heavy ship, weight, called ballast, must be increased in the hull of the ship. Ballast is usually composed of seawater, which is brought into the hull prior to a ship's voyage. The ballast water may also contain many organisms which can hitch a ride with the ship.

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Marina

"Cruising the Harbor"

Sailboats, motorboats, and other watercraft far outnumber the large container ships in the Charleston harbor and the Cooper River. Boats often "park" in large marinas where they can fill up with fuel, make repairs, and are safe from wave damage. Pump-out stations allow boats to unload sewage in a safe manner. Garbage cans, electricity, and convenience stores add to the advantages of a marina.

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ETV

Marina on Cooper River

Clue:

Point source pollutants, or pollutants that can be traced to a specific point or location, in the form of gas, oil, sewage, and chemicals can enter rivers at marinas. Marinas should not be located near sensitive wildlife.

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Suburbs

"A Growing City"

The population of Charleston and the surrounding area is booming! Many people who work in Charleston choose to live in the suburbs. Outside of the city, people enjoy shopping malls, golf courses, and more affordable living spaces. Currently, Mount Pleasant, a city on the Cooper River, is the third fastest growing city in South Carolina. To keep up with the population growth, land in the suburbs is continually being cleared for new homes, recreational space, business, and roads. Construction of hotels, beach and river houses, and other getaways for tourists and temporary residents is also a big industry.

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NOAA

Suburbs

USFW

Urban area, 1973

Clue:

Nonpoint source pollution is the result of water running off of the land and into waterways. When it rains, water flows through the suburbs picking up pollutants on driveways, streets and yards. Eventually this polluted runoff water finds its way into lakes, streams and rivers.

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USFW

Urban area, 2000

USFW

Projected growth, 2029

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Suburban Activity

"In Your Backyard"

What does your backyard have to do with pollution? A single lawn, yard, driveway, or garden may not be enough to spoil the environment. But a collection of them can greatly add to runoff pollution.

Excess water from car washing and lawn watering adds to runoff water entering streams and rivers. Household chemicals, motor oil, cleansers, fertilizers, insecticides and bacteria from pet wastes may find their way into a river through runoff water. Drains often lead directly into rivers and streams.

Permeable surfaces such as soil and grasses naturally filter out polluted water before it enters our waterways. Developed areas have lots of hard, or impermeable, surfaces such as roads, parking lots, and paved driveways. Hard surfaces allow polluted runoff water to flow rapidly into our waterways, instead of being filtered out by the soil.

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ETV

Suburban activity

ETV

Suburban activity

ETV

Suburban activity

Clue:

Runoff pollution can be decreased by homeowners if they:

- Use permeable surfaces, such as gravel, bark chips, and bricks in place of continuous hard surfaces. These materials allow water to seep into the ground.

- Decrease the use of fertilizers and insecticides near waterways and wetlands, or if possible, avoid using them altogether or use an organic substitute.

- Reduce unnecessary water usage.

- Clean up pet or farm animal wastes.

- Properly dispose of chemicals such as oil and paint thinner.

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Riparian Buffer Zone

"Guarding the Water"

Plants and trees protect a river from runoff pollution. A "riparian buffer zone" is one of the river's best defenses against runoff pollution.

Riparian refers to the land along streams, rivers, marshes, and shorelines. A buffer lessens or absorbs the impact of something.

Thus, a "riparian buffer zone" is an area along a river that absorbs the impact of runoff pollutants before they enter a body of water. Buffers are composed of trees, shrubs, grasses and other kinds of plants that hold tight to the soil. The State of South Carolina recommends a riparian buffer zone of at least 10.67 meters (35 feet).

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John Van Dyk

Riparian buffer zone

VDOF

Riparian buffer zone

Clue:

By absorbing and filtering polluted water, a riparian buffer zone of trees and plants can protect a river or wetland from runoff pollution. Native plants are the best because they require less water and fertilizer!

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Construction Site

"Building Boom"

A growing city is marked by the construction of new homes, schools, shopping centers and other structures. Construction creates the potential for adding sediment to a river or stream. Construction sites are often cleared of everything but the dirt foundation, and rain easily sweeps the sediment into waterways. Water that is too murky may be dangerous for fish and other aquatic organisms.

Sediment fences and detention ponds can prevent runoff. Sediment fences are simple barriers that keep sediment from flowing away from construction sites, and detention ponds collect rainwater and allow it to slowly seep into the ground.

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ETV

Construction site

ETV

Construction site

Clue:

Sediment fences and detention ponds protect waterways from runoff pollution created by construction sites.

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Estuary

"Mouth of the River"

All rivers end at the ocean. At the mouth of the river, freshwater from as far away as a mountain stream pours into the sea. Two times a day, tides push seawater into the estuary creating an ever-changing habitat for animals and plants.

Estuaries are narrow, ribbon-like patterns of ocean beaches, sand dunes, maritime forests, salt marshes, and tidal flats that extend for hundreds of miles along the coast. Because it is partially enclosed, the estuary acts as a "trap" for nutrients washed down toward the sea. This "soup" provides a home to many very different kinds of plants and animals…some found nowhere else. Each of these plants and animals has one thing in common. Every living thing in an estuary must be able to adapt to an environment that changes by the hour.

Content adapted from North Carolina National Estuarine Research Reserve Program

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NOAA

An estuary

Clue:

Two times a day, tides push seawater into the estuary, creating an ever-changing habitat for animals and plants.

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Eastern Brown Pelican

"Fish Beware!"

In the estuary, the sight of a large pelican diving head first into the water is quite a thrill. At the surface, the bird tilts its bill downwards to drain out water and then tilts the bill up to swallow its catch. The Eastern brown pelican is well adapted to using the estuary as a hunting ground.

Because of their large size, Eastern brown pelicans are a common sight in the harbor and salt marsh. They are one of the largest birds on the east coast, and can be seen resting on high piers, wading in the open water, or flying over the river and harbor.

The Eastern brown pelican is also the only pelican in the world that is not white. Adult pelicans are easily identified by the characteristic long bill with an underlying gular (throat) pouch. They can have a mass of up to 3.6 kilograms (8 lbs.) and live up to 30 years in the wild.

Currently, the brown pelican only nests in North Carolina, South Carolina, Florida, and Louisiana. The pelicans make their nests in areas high enough to avoid tidal flooding and far enough from mainland predators, such as raccoons. Nests are made in trees, such as mangroves, or in shallow depressions on the ground.

Scientific Name: Pelecanus occidentalis
Size: length: 1.2-1.4 m (45 - 54 in.), wingspan: about 2 m (6.5 ft.)
Range: Atlantic coast of United States
Life Span: about 30 years
Feeding Habits: small fish

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SCDNR

Eastern Brown Pelican

SCDNR

Eastern Brown Pelican with chick

Clue:

The chemical pesticide DDT, used in farming, entered coastal waters as runoff pollution. It endangered the brown pelican population and has been banned since 1972.

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Eastern Bottlenosed Dolphin

"A Coastal Friend"

Scan the surface of the harbor and the river and you might see a fin somewhat resembling that of a shark. The fin is more likely the fin of the Atlantic bottlenosed dolphin, a mammal, and a resident of South Carolina's coastal zone. Some dolphins stay close to the coast while others swim in the open ocean.

Unlike fish, dolphins breathe in open air. A dolphin comes to the surface and takes air in through its blowhole, which is connected to the lungs. The blowhole closes when the dolphin dives, so that water will not enter the lungs. Dolphins sleep near the top of the water, surfacing every few minutes so they can breathe through their blowhole.

For protection from predators such as sharks, dolphins often travel in small groups of four or five. In the winter, large groups of dolphins travel south to warmer areas. In the spring, the dolphins return to northern waters. Young dolphins will stay near their mother drinking her milk for about one to two years. They begin eating fish at about six months old.

Dolphins are extremely intelligent; they can memorize and imitate. They are also social animals that communicate with one another through high-pitched squeaks made by opening and closing their blowholes. Each dolphin even has a special squeak that serves as its own name! In times of need, dolphins often help one another. If one dolphin is sick, others try to care for it. Dolphins have even been known to rescue drowning humans!

Scientific Name: Tursiops truncatus
Size: about 2.5 m (8 ft)
Range: East Coast of the United States
Life Span: up to 25 yrs
Feeding Habits: Dolphins hunt at the water's surface for fish, shrimp, crabs, and squid.

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NOAA

Eastern Bottlenosed Dolphin

NOAA

Eastern Bottlenosed Dolphin

NOAA

Eastern Bottlenosed Dolphin

Clue:

The chemical compound PCB, or polychlorinated biphenyl, has been found in the blubber of dolphins. This compound was once used in industrial cooling and disposed of by dumping into landfills and burning. PCB's may also have leaked from old equipment into the environment. PCBs do not break down easily, and can be passed to offspring through a mother's milk.

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Red Drum

"Eyes in Disguise"

Scientists believe the spot on the red drum's tail confuses predators into attacking its tail instead of its head, giving the fish a better chance to escape. The red drum, also called "channel bass" or "spottail bass," is a member of the drum family, Sciaenidae, and a close relative of Atlantic croaker, spot, and kingfish. Red drum are reddish-bronze with a distinct spot or spots at the base of the caudal fin.

Adults are normally found in near-shore and coastal waters while juveniles are normally found in the shallow creeks that meander through the cordgrass (Spartina alterniflora) marshes. Red drum males produce "drumming" sounds during the spawning season to attract females.

The red drum spend their first few months feeding on plankton. Once the larvae have moved to the estuary, they will feed on crustaceans and small fishes. When water temperatures rise in the spring, small red drum reenter the tidal marsh creeks and begin to grow very rapidly. In May and June, these fish begin to leave the small creeks for the open shallows of the estuary.

The red drum's predators include man and dolphins. The red drum has been placed on lists of fish that have been fished into a state of decline. Red drum numbers in South Carolina have increased in recent years, but commercial fishing is still restricted.

Scientific Name: Sciaenops ocellatus
Size: up to 1.5 m (58 in.), mass: up to 41 kg (90 lbs.)
Range: Delaware to southern Florida
Life Span: up to 30 years
Feeding Habits: fish, small crabs, grass shrimp, and bottom-dwelling organisms

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ETV

Red Drum

ETV

Red Drum

SCDNR

Red Drum

Clue:

Mercury, a toxic metal, has been found in red drum as well as many other fresh and saltwater fishes. The EPA, or Environmental Protection Agency, sometimes recommends limiting the amount of fish one eats because mercury levels in water are too high. Larval phases live in the protected habitat of the salt marsh.

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SCDNR

Red Drum (larval)

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Blue Crab

"A Seafood Delight"

During the summer, people line coastal creeks and rivers hoping to pull in blue crabs. Blue crabs tolerate a wide range of water conditions, and can be found in saltwater and fresh water. Their preference is usually for brackish water, a mixture of fresh and salt water that can be found in the salt marsh. Tidal water pushing upriver creates the perfect environment for the crab.

Like all arthropods, the blue crab has a hard exoskeleton for protection and support; however, the exoskeleton must be shed as the crab grows. Before the crab molts its hard outer shell, a new shell is being formed underneath the old one. By the time the old shell is molted, the new one is ready. The new shell will harden more over time. Soft-shell crabs are a prized seafood.

Once fertilized, blue crab eggs go through a series of developmental stages. As larvae, they feed upon zooplankton and as adults they feed on small fish, other crustaceans (including other blue crabs), mollusks, and decaying animal and plant matter. The adults spend more of their time in the estuary. Red drum and humans are the primary predator of the blue crab.

Scientific Name: Callinectes sapidus
Size: width: up to 23 cm (9 in.)
Range: coastal waters from Nova Scotia south to Argentina
Life Span: about 3 years
Feeding Habits: Larvae eat zooplankton, while adults eat larger prey including fish and decaying plant/animal matter.

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SCDNR

Blue Crab

SCDNR

Red Drum

SCDNR

Red Drum

Clue:

Blue crabs are an important part of the food web as hunters, scavengers and prey. Recent studies show that blue crabs keep marsh periwinkle from overpopulating. Currently, scientists are also researching a decline in blue crab populations. Red drum are known to eat blue crabs.

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Alicia Young Williams

Blue Crab (larval)

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Shrimp

"A Seafood Delight"

Commercial shrimping is an important part of the economy of South Carolina. There are many kinds of shrimp found in the salt marsh and estuary, including pink, white, and brown shrimp.

As planktonic larvae, shrimp eat other zooplankton, and as adults they eat detritus, small marine worms, small fish, and microalgae. White and brown shrimp primarily live upon a muddy bottom while the pink shrimp like a more sandy or shell-like bottom. In South Carolina, there are fewer pink shrimp than white or brown shrimp because of primarily muddy-bottomed waters.

Shrimp have walking legs to help them move short distances, while their swimming legs help propel them longer distances. To escape predators, shrimp can use their abdominal muscles and other appendages to quickly move backwards.

Scientific Name:
White shrimp: Penaeus/Litopenaeus setiferus
Brown shrimp: Penaeus aztecus or Farfantepenaeus aztecus
Pink shrimp: Farfantepenaeus duorarum
Size: up to 15 cm (6 in.)
Range: near shore and inshore waters from Massachusetts to Mexico
Life Span: about 2 years
Feeding Habits: omnivores that will eat any available food

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SCDNR

White Shrimp

NOAA

White Shrimp

SCDNR

Shrimping along the river

Clue:

Shrimp are a very profitable and useful food source. Because shrimp consume detritus and benthos, they are important to the food web of the salt marsh. Larval planktonic shrimp use small salt marsh creeks as nursery grounds, where they are heavily preyed upon by many marine animals.

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SCDNR

Shrimp life cycle

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Plankton

"It's a Small World"

Estuaries are rich with plankton. Plankton is a term for a group of extremely small creatures found in fresh and saline waters. A liter of lake water has been known to contain 500 million forms of planktonic life. Most plankton have no real control over where they go because of their small size.

Plankton are one of the most important pieces of the aquatic food web. There are two main types of plankton: phytoplankton and zooplankton.

The phytoplankton, composed mainly of diatoms, dinoflagellates and the algaes, make their own food through photosynthesis. Since phytoplankton make their own food through photosynthesis like a plant does, they have to be near the surface of the water in order to have access to the sun. Several types of phytoplankton have special adaptations that help them to stay afloat near the surface of the water. Copepods, like diatoms, secrete an oil to help them remain high in the water column. The Portuguese man-of-war is phytoplankton that has an air sac to help it stay afloat.

The more animal-like zooplankton mostly feed on the phytoplankton, but can also feed upon other aquatic organisms. The zooplankton include foraminifera, small crustaceans, jellyfish, worms, mollusks, and some egg and larval forms of other animal species found in the waters. Like phytoplankton, zooplankton have special adaptations that help them to survive in their environment.

Size: most are microscopic
Range: found in all water ecosystems, fresh and saline.
Life Span: a week to a few months
Feeding Habits: Like plants, phytoplankton produce their own food through photosynthesis. Zooplankton feed upon phytoplankton.

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NOAA

Zooplankton

NOAA

Phytoplankton

NOAA

Zooplankton (Man-of-War)

Clue:

Phytoplankton is the primary producer of all aquatic food chains. Too many nutrients in the water can cause an outbreak of plankton called a red tide, which has been known to poison fish, turtles, shellfish, and the humans that eat them.

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Bacteria

"It's a Small World"

For nearly 2 billion years, bacteria were the only form of life on earth. Bacteria are microscopic, one-celled organisms. They are found everywhere on earth: the frozen arctic, the dry deserts, the deepest oceans, boiling hot springs and even on and in the bodies of living organisms!

Though some bacteria can cause disease and sickness, bacteria are very important organisms of every ecosystem. They feed on organic matter, decomposing it in order to return nutrients to the soil. Bacteria are also an important part the nitrogen cycle. Nearly all forms of life need nitrogen. Nitrogen is abundant in the atmosphere; however, it is not useable to most organisms in that form. Bacteria living in the soil will "fix" the nitrogen gas into compounds that plants can use, and then animals can get the "fixed" nitrogen compounds when they eat plants. When the animals and plants die, bacteria decompose these nitrogen compounds back into atmospheric nitrogen. This constant movement of nitrogen through the environment is called the nitrogen cycle. Without bacteria, plants could not absorb nitrogen and whole ecosystems would fail!

Like plants, some bacteria make their own food through photosynthesis; other bacteria make their own food through chemical processes, and still others feed on smaller bacteria in a process called phagocytosis.

The bacteria that people give a "bad rap" are known as pathogens. Pathogens are microscopic invaders that can cause disease, but most bacteria are harmless and, in fact, helpful.

Size: most are microscopic
Range: everywhere
Life Span: several days
Feeding Habits: Some are heterotrophs, while others are autotrophs.

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KCDNR

Bacteria

EPA

Fecal coliform under electron microscope

Clue:

Fecal coliforms are bacteria that live in the digestive tract of warm-blooded animals (humans, pets, farm animals, and wildlife) and are excreted in the feces. Fecal coliforms are often found in fresh and salt water. Fecal coliforms usually do not pose a danger to people or animals, but they are good excreted in the indicators of other disease-causing bacteria.

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Ships in the Charleston Harbor

"A Busy Seaport"

The Charleston harbor is an important estuary and a busy seaport. Estuaries at the mouths of rivers are protected from the open ocean by marshes, dunes, and coastal sea islands. Because estuaries are partially enclosed areas, they are often chosen as locations for seaports.

In the harbor, freighters carry containers to and from international locations. Tankers bring oil into the United States through the harbor. All of these ships move through a network of shipping channels, marked by buoys on the surface of the water. In Charleston, managing the shipping channels and traffic is a full-time job, and since the harbor is also an estuary, environmental and economic issues are sometimes at odds.

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ETV

Ships in Charleston Harbor

Clue:

In September of 2002, a container ship in the Charleston Harbor leaked almost 50,000 liters (12,500 gallons) of fuel oil into the water. Some oyster beds covered with the oil had to be closed. A criminal investigation has been filed to see if the ship's pollution controls were functioning properly.

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Dredging Ship

"Scraping the Bottom"

Deltas are formed when sediment from upriver collects at the mouth of a river. These fan-shaped deposits of sediment often make harbors too shallow for large container ships, tankers, and other boats. Dredging is the act of deepening a shipping channel by scraping layers of sediment from the bottom of the harbor. The sediment is then deposited on nearby islands or other parts of the river.

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USACE

Dredging Ship

USACE

Dredging Ship

Clue:

Most chemical contaminants are hydrophobic, which means they do not dissolve or combine with water. Because of this, these contaminants often settle into the sediment at the bottom of rivers. This polluted sediment can be stirred up every time a river is dredged, which may cause a periodic threat to wildlife.

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Commercial Fishing Vessel

"Fishing for a Living"

Fishing, crabbing, and shrimping are an important part our state's economy and culture. People in the coastal zone have harvested seafood for over 10,000 years. In the estuary, access to both the open ocean and rivers in the tidal marsh allow for a diverse catch of shellfish, crustaceans, and fish.

With populations booming around the world, the demand for seafood is booming as well. Today's commercial fishermen face many challenges. Over-fishing of some species has led to severe limits or bans on harvest. Overdevelopment of marsh land and coastal property can destroy the habitats of many species of seafood and affect their populations. Pollution can also have an effect on the population of some species of shellfish, or may affect the quality of seafood making it inedible for humans.

In South Carolina, it is the responsibility of the Department of Natural Resources (DNR) to manage populations of marine wildlife. By limiting the number of licenses available to the fishing industry, the DNR ensures that fish, shellfish, and crustacean populations are preserved for future generations.

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ETV

Commercial Fishing Vessels

SCDNR

Commercial Fishing Vessels

Clue:

A steady decline in the Blue Crab population has been blamed on over-harvesting; however, many crabbers believe that pollution is the problem, not over-harvesting. Others believe that drought has resulted in less freshwater entering the marsh, causing crabs to move upstream to brackish water. Because crabbers are not allowed to enter more sensitive upstream areas, they do not have access to the crabs.

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Cooper River Bridges

"Bridging the Harbor"

Two striking bridges over the Cooper River tell the story of Charleston's growth during the 20th century. The Grace Memorial Bridge (1929) and the Silas N. Pearman Bridge (1968) span the mouth of the Cooper River. At the time of its construction, the Grace Memorial Bridge had the 5th largest main span in the nation.

These bridges connect Charleston to the suburb of Mount Pleasant, the 3rd fastest-growing town in the state. With improved access to Mount Pleasant, a once rural area began to experience growth. During the 1970s, Charleston greatly expanded its seaport and tourist trade. Mount Pleasant's population of 6,155 in 1970 has grown steadily to a current population of 53,000 people.

Today, the Cooper River bridges are too low to accommodate taller, modern ships. To continue the growth of Charleston's seaport and provide safer, easier access to suburban areas, a new Cooper River Bridge is being built. The new Cooper River Bridge will be the largest suspension bridge in the Western Hemisphere. The two old Cooper River bridges will be torn down after the new bridge's completion, scheduled for 2005.

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ACSE

Cooper River Bridges

DMA

New Cooper River Bridge (2005)

Clue:

The enormous size of the new Cooper River Bridge has created concern for how it might impact communities and wildlife habitats. Engineers and city planners have tried to address these concerns with the bridge's design. Detention ponds built at the ends of the bridge will filter runoff water before it enters rivers and creeks. New on-ramps are designed to lessen traffic through communities near the bridge.

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River Wrap

Ready to file a River Wrap?

Use what you've learned to answer the following ten questions.

If you need help, use your notebook of continue to explore the area.

You can leave and return to the River Wrap at any time during your visit.

Click begin when you're ready!

Begin

Question 1.

Filter feeders are an important part of the salt marsh. Choose the best answer to explain why:

  1. Filter feeders like flounder keep the bottom of the ocean clean by eating decaying matter found there.
  2. Pollutants are removed by filter feeders as they filter water for edible material.
  3. Filter feeder systems found at marinas and ports absorb polluted water and release special anti-pollution agents into the waters.
  4. Bacteria use the filter feeders inside of them to remove pollutants before they ingest the water.

Yes, that's right!

The oyster is a filter feeder capable of filtering up to 190 liters (up to 50 gallons) of water a day! More filter feeders in a salt marsh mean fewer pollutants in the water.

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Question 2.

The eastern oyster is a mollusk common to the salt marsh. What other mollusks are found in this salt marsh?

  1. Larval blue crab, marsh periwinkle, larval shrimp
  2. Ivory barnacle, hard clam, marsh periwinkle
  3. Green porcelain crab, shrimp, blue crab
  4. Ivory barnacle, hard clam, larval shrimp

Way to go!

These are all mollusks found in the salt marsh. Mollusks such as oysters and clams are a favorite seafood of South Carolinians. Certain kinds of snails even make it into our restaurants.

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Question 3.

What kinds of larval life are protected by the salt marsh?

  1. Loggerhead turtle, blue crab, porcelain crab
  2. Brown pelican, American oystercatcher
  3. Blue crab, shrimp, red drum, flounder
  4. Dolphins, flounder, shrimp

Very good!

Because larvae are small and cannot move around very well, they would be vulnerable to predators found in deeper waters.

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Question 6.

What should we do to protect water quality near oyster beds?

  1. Not allow power plants to work since they create pollution
  2. Not allow boats to use the waterways when there is an oyster bed closure
  3. Build buffer zones using nonnative plants to introduce diversity
  4. Clean up pet wastes, use permeable surfaces and fewer pesticides

Excellent!

Runoff water can carry pollutants from yards and gardens, over hard surfaces, and into waterways.

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Question 8.

Nonpoint source pollutants are the result of runoff water bringing pollutants from the land into our waterways. What is the best solution for nonpoint source pollution?

  1. Riparian buffer zones, sediment fences, permeable surfaces, fewer chemical pesticides
  2. Recycling, pesticides, dredging, waste treatment centers, filtration devices
  3. Jetties, drains, and heavy rain
  4. Water sampling, DHEC, estuaries, and PCBs

Yes, that's right!

Buffer zones, sediment fences, permeable surfaces and fewer pesticides prevent pollutants from entering waterways.

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Question 9.

Riparian buffer zones protect waterways from runoff pollution. Which combination of plants would be best for a coastal buffer zone?

  1. English ivy, kudzu, and live oak
  2. Sediment fences, St. Augustine grass and eucalyptus
  3. Azaleas, cabbage palmetto, and spartina
  4. Live oak, cabbage palmetto, and spartina

Very good!

Native plants need less fertilizer and water to grow, which helps to prevent runoff pollution.

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Question 10.

What is the best explanation as to why the oyster bed in this website was closed?

  1. A water sample revealed high levels of fecal coliform due mainly to an oil spill.
  2. There were high levels of oxygen due mainly to acid rain.
  3. A water sample revealed high levels of fecal coliform due mainly to a red tide algal bloom.
  4. A water sample revealed high levels of fecal coliform bacteria, most likely the result of runoff pollution.

That's right!

Fecal coliform indicates the presence of other, more dangerous, bacteria that may be ingested by oysters and then ingested by humans.

Continue

Congratulations!

You've successfully completed the River Wrap!

Join us here at www.riverventure.org later in 2004 to visit new locations along the rivers of South Carolina!

Visits to Columbia and the Blue Ridge Mountain areas coming soon!

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Aerial Photograph

Charleston Harbor and Estuary

This aerial photo was taken with infrared film from 20,000 feet above the earth. Infrared film produces altered images that reveal details about the vegetation or hydrology of an area. The photo was taken during the winter.

Red: Healthy green vegetation
Blue-Gray: Developed land/urban
Light Blue: Sediment laden water
Royal Blue: Water
Black: Clear water
Green: Wetland / shallow water

Nautical Map

Charleston Harbor and Estuary

Nautical maps help ship captains and recreational boaters navigate waterways. This nautical map shows the network of creeks, marshes, rivers, islands, and open water that make up the Charleston Harbor and Estuary. Major shipping channels, bridges, roads, and highways of charleston are also featured on the map.

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abdominal
hindmost body region
adaptations
unique behavoir or structure that assists an organism in its environment
aggregate
formed by a mass or collection of particles
alluvial
deposits made by flowing water
appendages
part of a body, such as an arm or leg, that is attached to the trunk
archaeologists
someone who studies remains from past human lives
ban
official statement saying something in illegal or not allowed
benthos
organisms (plants and animals) that live at or near the bottom of lakes, waterways, and oceans
bloom
when a population grows quickly
blowhole
hole on top of a dolphin's head that is attached to its lungs
blubber
wide layer of fat between the skin and muscles
Blue Ridge
the rugged, mountainous region of northwestern South Carolina, sometimes referred to as the "upcountry"
brackish
a mixture of fresh water and saltwater
buffer zone
a protected area of trees and plants along a river that prevents runoff pollution and erosion
buoy
floating marker
camouflage
hiding or disguising by blending in with natural surroundings
caudal
tail fin of a fish
Civil War
war between the states mainly concerning the issue of slavery and state's rights; 1861-1865
Coastal Plain
a large, relatively flat region of southern South Carolina characterized by meandering rivers, sqamps, agriculture, and pine forests
Coastal Zone
the coastal region of South Carolina characterized by beaches, dunes, marshes, seaports and heavy tourism
colony
a group of related organisms living or growing together
confluence
a point where two rivers merge to form a single river
consume
to eat or take something in
converge
place where two things come together
copepods
one of a variety of tiny crustaceans
cross-fertilization
when the sperm and the egg from two individual organisms meet and begin the growth process of new organisms
debris
unwanted material
detritus
eroding matter; a mass of dead or decaying Spartina grass
diatoms
one of a variety of microscopic algae that are either one-celled or live in groups
dinoflagellates
algal organisms with two "whip-like" tails, or flagella
dredged
to remove dirt from the earth and deposit it elsewhere
estuary
the area of a river where it nears the sea; fresh and salt water mix in an estuary
excreted
to release from the body
exoskeleton
hard outer covering found on some animals
feces
solid waste expelled from an organism
fertilization
when sperm and egg of a species meet and begin the growth process of new organism(s)
foraminifera
very small unicellular heterotrophs with a shell
freighter
large ship that transports goods
hermaphrodite
an organism that can produce both egg and sperm
hull
frame of a ship; usually referring to the bottom of the ship
hydrology
the study of water and its interaction with the land, sea and sky
imitate
to copy
indicator
showing the presence or absence of a substance
industrial cooling
use of water to cool down machinery
Industrial Revolution
a period from the 1860s to the early 1900s during which the nation moved from an agricultural to an industrial economy
inedible
something not to be eaten
infrared
beyond the red, or lower-frequency (longer wavelength), end of the visible spectrum of light rays
infrastructure
the basic facilities that provide transportation, communication, education, sanitation, power and water to a community or society
invasive species
a species that is non-native (or alien) to the ecosystem which is likely to cause economic or environmental harm
jetty
a structure used to prevent tidal, storm, or water current erosion along a harbor or shoreline
lock
a structure on a waterway or canal that raises and lowers boats in transit
molt
when an outer covering is shed; it will be replaced by new growth
neurotoxin
a poison that destroys nerve tissues
nonpoint source pollution
pollution that cannot be traced to any one source or point
perennial
a plant that reoccurs and lives three or more years
permeable
having pores or openings that allow small materials to pass through
phagocytosis
whan a bacterial cell ingests solid matter by surrounding and digesting it
Piedmont
the northern half of South Carolina where rolling hills mark the transition of the Blue Ridge Mountains to the flatter Coastal Plain
plankton
a collection of small or microscopic plant and animal organisms that float or drift in fresh and salt water
plasticity
the degree to which a material can be shaped or formed
point source pollution
pollution that can be traced to a single source or point
Portuguese man-of-war
jellyfish that is made up of smaller organisms that function as one
recreational
activity done for fun
Revolutionary War
war fought by the U.S. colonists to win independence from Great Britain; 1775-1783
river corridor
the environment along the banks of a river that is influenced by the waterway
salinity
the proportion of salt in a solution
Sandhills
the hilly, central area of South Carolina that was a prehistoric beachfront (55-100 million years ago) and is marked by deposits of sand and sedimentary rock
sedentary
staying or living in one spot
ship ballast
water or other weight that is removed or added as needed in order to ensure stability
sluice
a valve or gate that allows water to pass through
spawning
reproduction of organisms or the eggs that result from reproduction
substrate
surface upon which an organism attaches and lives; also used to refer to the soil on the bottom of a body of water
tanker
large ship used to transport oil or fuel
textile
cloth
turbine
a rotary engine that converts flowing water into mechanical energy
unsanitary
unclean
varnishing
liquid that is applied to seal or cover a surface
vegetation
plant life of a particular region
vulnerable
defenseless or able to be hurt
wastewater
untreated water, or sewage, that is deposited down drains and sewers by residents and businesses
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ETV

Panorama of a marina, Charleston, South Carolina

ETV

Panorama of Battery Park, Charleston, South Carolina

ETV

Panorama outside the SC Aquarium, Charleston, South Carolina

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Marina on Cooper River

Charleston, South Carolina

Recreational boats crowd a large marina on the shore of Mount Pleasant, a rapidly developing community east of Charleston. The Cooper River Bridge, a loading crane from a container port, and the skyline of Charleston can be seen in the distance. The open water area is a major shipping channel leading up the Cooper River.

Battery Park

Charleston, South Carolina

Battery Park overlooks the harbor and estuary at the end of the Cooper River. The park was once the location of a battery of guns and fortifications that protected Charleston during the Revolution and the War of 1812. From this seawall, one would have witnessed a blockade of the harbor by Blackbeard's fleet of pirate ships (1718), a major naval battle of the Revolutionary War (1776), and the first shots of the Civil War, fired a Fort Sumter in 1861. Battery Park is one of Charleston's most popular tourist attractions.

South Carolina Aquarium

Charleston, South Carolina

A large container crane can be seen in this view from the South Carolina Aquarium. Ships pulling into the harbor unload their cargo using cranes like this one. The Cooper River Bridges can be seen in the distance. The aquiarium features aquatic habitats found from the mountains (Blue Ridge) to the sea (Coastal Zone).

For more information, go to www.scaquarium.org.

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