coastal+zone

= The Coastal Zone = By: John, Mark, and Ian toc

**Introduction**
= = The coastal zone is an aquatic ecosystem. It is shallow, less than 200 m, and covers about 7% of the [|global ocean area]. It is narrow and a dynamic transitional zone between the [|marine] and land sub-systems. Its area includes the foreshore, the beach area, and natural coastal protection systems such as dunes and mangroves. Most of the land-based materials that enter this area are from either surface runoff or groundwater flow. This area makes up for at least 15% of the oceanic primary production, 80% of organic matter burial, 50% of the deposition of calcium carbonate, and 90% of sedimentary mineralization. Despite these facts, this zone has been relatively ignored by people until recently. Now it is the primary focus of many different [|researching groups.]

**Plant and Animal Life**
There is a plethora of plants and animal species in the Coastal Zone. There are many type of crabs, jelly fish, and sea turtles. It is inhabited by many fish species and predators such as sharks, [|horseshoe crabs], and other large [|crustaceans]. Many seabirds also live in this area. These include Pelicans, [|Terns], and [|oystercatchers], and hunt fish and different shellfish along the coast. Finally, is the plant life of this zone. There are kelps and seaweeds throughout this zone.



**Physical Traits**
There are many different types of coastal zones. These Zones include sandy beaches, muddy coasts, rocky coast, arctic coasts, and barrier coasts. Each of these different coasts have different traits and different organisms that live there.


 * Sandy Beaches: **Sand is a very common marine sediment and is transported along the [|shoreline]. It is driven by the breaking waves and the long shore currents in the wave breaking zone. The appearance of the natural sandy beach is determined by hydrographic conditions and geology of the beach. Any interference will cause a reaction in the form of a shoreline response. Knowing about the physical processes is important to keeping the shoreline in tact.

**Muddy Coasts:** Muddy coasts are only found in environments that are calm with respect to the wave conditions, or if there is abundant supply of fine sediments. They are normally vegetated with [|mangroves] fronted by very flat slopes or muddy coast with mangrove vegetation which is characterized by a muddy shore face. These are sometimes in the form of muddy tidal flats, and lack of a sandy shore.


 * Rocky Coasts: **Rocky coasts are continuously cut back by the sea and are characterized by [|erosional] features. They have a slow rate of [|morphological] change, and experience the main erosional processes of mechanical wave erosion, abrasion and hydraulic action. The all experience weathering with physical, salt, chemical and water-layer levelling. Also there is bio-erosion with biochecmial, biophysical and mass movements by rock falls and toppling, slides and flows.


 * Arctic Coasts: **Shores that are above the North Polar Circle, which are exposed for more than six months of freezing annually are regarded as Arctic Coasts. Their characteristic feature is the importace of ice forms for their ecology and [|evolution]. Ice acts as a limiting factor for the occurrence of infaunal and epifaunal organisms. In places, with very cold water, where permafrost surface at the intertidal, the specific type of arctice shore appears, The cryolittoral is where freshwater ice forms the seabed. Soft sediment arctic coasts are eroding very fast due to the combined effect of ice melt, ice scouring and wave action.


 * Barrier Coasts: **Barrier islands are parallel to the shore, separated from the mainland by a lagoon. In a profile with a more gentle slope than the equilibrium profile. Sediments will be moved onshore, as waves on the shore face will primarily transport sand towards shore attempting to build up and equilibrium profile. Waves lose their energy over the gentle shore face and deposition occurs away from the shore line. Which eventually develops into a barrier island due to the cross-shore transport.

Video
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