Have a seat quickly and quietly

Today we will be learning about estuaries.

What is an Estuary?

Adapted from http://web.utk.edu/~ctmelear/ossabaw/PattersonStanfordSutton/estuaryL2.html

• Estuary-- a body of water formed where freshwater from rivers and streams flows into the ocean, mixing with the saltwater; a place of transition between land and sea

• Estuary water is known as brackish- a mixture of salt water and fresh water; salinity is lower than saltwater but higher than freshwater

What is an Estuary?

• Estuaries are influenced by the tides but are protected from the force of ocean waves, winds, and storms by the reefs, barrier islands, or fingers of land, mud, or sand that define an estuary's seaward boundary.

• Estuaries come in all shapes and sizes and go by many different names, often known as bays, lagoons, harbors, inlets, or sounds.

• Some familiar examples of estuaries include San Francisco Bay, Puget Sound, Chesapeake Bay, Boston Harbor, and Tampa Bay.

What is an Estuary?

• The waters of estuaries support unique communities of plants and animals, specially adapted for life at the margin of the sea.

• Estuarine environments are among the most productive on earth, creating more organic matter each year than comparably-sized areas of forest, grassland, or agricultural land.

What is an Estuary?

• Many different habitat types are found in and around estuaries; along the US coasts, most are wetlands and are either mangrove forests or salt marshes

Mangrove Forest• Have arching prop roots that anchor the trees to

the land• Roots break up wind and waves protecting

organisms that live there• Roots also trap sediment so water is rich in

nutrients

What is an Estuary?

Salt Marsh• Have muddy soil that is rich in nutrients• Dominant plant is cord grass• Tide channels running through the grass break

up waves, protecting organisms from the ocean surf

What is an Estuary?

Why Are Estuaries Important?

They are critical for the survival of many species.

• Birds, fish, crustaceans, mammals, shellfish, marine worms, and reptiles link to one another and a variety of plants and microscopic organisms through complex food web

• Wildlife depends on estuarine habitats as places to live, feed, and reproduce.

• Estuaries provide ideal spots for migratory birds to rest and refuel during their journeys.

• Many species of fish and shellfish rely on the sheltered waters of estuaries as protected places to spawn, giving them the nickname “Nurseries of the Sea.“

• Hundreds of marine organisms, including most commercially valuable fish species, depend on estuaries at some point during their development.

Why Are Estuaries Important?

Why are Estuaries Important?

Estuaries work as a natural filtering system

• Water draining from the uplands carries sediments, nutrients, and other pollutants.

• As the water flows through fresh and salt marshes, much of the sediments and pollutants are filtered out.

• This filtration process creates cleaner and clearer water, which benefits both people and marine life.

Why are Estuaries Important?

Estuaries provide stability.• Wetland plants and soils also act as a natural

buffer between the land and ocean, absorbing flood waters and dissipating storm surges.

• This protects upland organisms as well as valuable real estate from storm and flood damage.

• Salt marsh grasses and other estuarine plants also help prevent erosion and stabilize the shoreline.

Estuaries of North Carolina

• North Carolina’s system of estuaries spans a surface water area of about 3000 sq miles; second only to Chesapeake Bay in United States

• North Carolina estuaries are shallow (<30 ft); this means sunlight can usually penetrate through the water, leading to increased photosynthesis, plant growth, and usable habitat for a huge variety of organisms

Estuaries of North Carolina

• Great Dismal Swamp- northeast corner of NC, shared with southeast Virginia

• Pamlico Sound- largest in NC; separated from Atlantic by the Outer Banks (barrier islands)

• Crystal Coast Salt Marshes- stretch along the Crystal Coast beaches of NC (Emerald Isle to Pamlico Sound)

Estuaries of North Carolina