Characteristics of major types of coastal zones By Rema Faddoul

Major Types Include: Estuary – Chesapeake Bay largest estuary in the United States is located off the Atlantic Ocean. Salt Marshes Along the Heathcote River, Christchurch, New Zealand Mud Flats Cobequid Bay, Nova- Scotia

Estuaries Partly enclosed coastal body of water with one or more rivers/streams flowing into it and a free connection to the open sea Economically significant as seaports, centers of ocean commerce and commercial fisheries They exist today because sea level has risen approximately 120 m since the glaciers started melting 18,000 years ago

4 Major Classes of Estuaries Coastal Plain Estuary Fjord Bar-Built Estuary Tectonic Estuary

Coastal Plain Estuary Form when sea level rises and floods existing river valleys Ex. Chesapeake Bay in Maryland and Virginia

Fjord (pronounced Fee-yord) Forms when sea level rises and floods a glaciated valley Typically has a U-shape with steep walls Common in Alaska, Canada, New Zealand, Chile and Norway

Ex. Pamlico Sound in North Carolina Bar-Built Estuary Shallow and separated from open ocean by sand bars parallel to the coast Lagoons that separate barrier islands from main land are bar built estuaries. Ex. Pamlico Sound in North Carolina

Ex. San Francisco Bay due to movements along the San Andrea Fault Tectonic Estuary Forms when faulting/folding of rocks creates a restricted down dropped area into which rivers flow Ex. San Francisco Bay due to movements along the San Andrea Fault

Salt Marshes General Information The Specifics Intermittently submerged by ocean water Support a variety of grasses Serve as nurseries for commercially important fish Stopover point for many species of waterfowl and migratory birds Flounder and bluefish use marshes for feeding and protection in winter Oysters, scallops, clams, eels and smelt are located in marshes Efficient at cleansing polluted water from agricultural runoff and toxins

Salt Marsh at Fort Fisher State Recreation Area

Mud Flats Generally found next to salt marshes and sheltered areas like bays, bayous, lagoons Form when mud is deposited by tides and rivers Most sediment within a mudflat is within the intertidal zone, thus submerged/exposed twice daily due to tidal flow Organisms found in mud flats include eelgrass, turtle grass, crabs, mud snails and filter feeders due to presence of plankton. Below the surface one can find burrowing animals such as clams, worms and crustaceans Mudflats are under threat from predicted sea level rises, land claims for development and chemical pollution

Teshekpuk Lake On the Arctic Coast of Alaska