12/23/2023 0 Comments Tidal pool food web![]() ![]() Tides result from the moon and sun’s gravitational pull on the earth’s oceans. The tidal range, or difference between low and high tide, ranges from about ten feet (3m) in Georgia to about three feet (1m) in North Carolina and Florida. The Southeastern salt marsh-tidal creek ecosystem has semi-diurnal tides, meaning they experience two high tides and two low tides each day, each lasting about six hours. The major physical variables influencing the salt marsh-tidal creek ecosystem include the tides, salinity, sediments, air and water temperature, precipitation, and sunlight. The flora and fauna of this ecosystem are adapted to changes in environmental conditions that occur hourly, daily, seasonally, annually and on even longer time scales. The abiotic or physical properties of the salt marsh-tidal creek ecosystem are extremely variable and strongly influence the system’s biotic properties, which include the productivity, diversity, and abundance of plants and animals that occur there. Physical Properties of the Salt Marsh Ecosystem As vast expanses of salt marsh grew, runoff from adjacent uplands in combination with the rising and falling tides resulted in the creation of numerous tidal creeks which transect the marshes. The roots and stems of Spartina trapped incoming sediment and stabilized it, thus creating a marsh platform. The elevation of the sand bars and mud flats rose above low tide, giving salt tolerant plants ( halophytes), particularly Spartina alterniflora the opportunity to grow. Freshwater input from major river systems deposited sand and fine sediments in the shallow regions creating sand bars and mud flats. As sea level increased and salt water moved inland, bays and lagoons formed behind barrier islands along the Southeast coast. Today’s salt marsh-tidal creek systems began to form about 12,000 years ago, at the end of the Pleistocene epoch when the glaciers that covered much of the earth started to melt and sea level began to rise. Kiawah Island, South Carolina How Did Salt Marsh Systems Form? This guide focuses on salt marsh-tidal creek systems which have salinities between 10-35 ppt, and are dominated by a plant called smooth cordgrass, scientifically known as Spartina alterniflora. Between these two extremes, the salinity of the salt marsh-tidal creek ecosystem varies greatly depending on tidal stage, amount of rainfall, and size of river system. ![]() Closer to the ocean, salt marshes and tidal creeks are saltier with salinities ranging between 20-35 ppt. As you travel up the river, salt marshes and tidal creeks have a low salinity, less than 5-10 ppt. Freshwater is 0 parts per thousand (ppt) and the Atlantic Ocean is 36 ppt. They are dynamic systems with varying levels of salinity, or salt in the water. In the Southeast, salt marsh-tidal creek ecosystems are generally found in estuaries along the flanks and behind barrier islands such as Kiawah Island, S.C., and Tybee Island, GA, as well as along the flanks of larger estuarine systems like the Savannah River, the Charleston Harbor, or the Cape Fear River. ![]() The northeast Florida Atlantic coast also has approximately 83,000 acres of salt marsh and tidal creek habitats. These three states combined support nearly two-thirds of salt marsh habitat found along the east coast. South Carolina and Georgia each have approximately 350,000 acres of salt marshes and tidal creeks North Carolina has about 225,000 acres. It is, however, most abundant in the Southeast (North Carolina, South Carolina, Georgia, Florida). A dendritic, or finger-like, network of tidal creeks winds through the marsh and facilitates the movement of tidal water onto the marsh surface and back into the estuary.Īlong the Atlantic coast of the United States, the salt marsh-tidal creek ecosystem occurs from Maine to Florida. As an intertidal habitat, the surface of the salt marsh is under water at high tide and dry at low tide. The salt marsh-tidal creek ecosystem is a highly productive coastal wetland that occurs between upland areas, such as forests and urban environments, and estuaries, where fresh and salt water mix. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |