coastal space
Introduction
A coast, also called coastline, coastline or seashore, is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. [1][2] Coastlines are influenced by the topography of the surrounding landscape, as well as erosion induced by water or waves. The geological composition of rock "Rock (geology)") and soil determines the type of coast that forms. The Earth contains approximately 620,000 km of coastline.
Coasts are important areas of natural ecosystems, often hosting a wide variety of biodiversity. On land they host important ecosystems such as freshwater wetlands or estuaries, which are important for populations of birds and other land animals. In areas protected from waves, they are home to salt marshes, mangroves or seagrasses, which can provide breeding habitats for fish, shellfish and other aquatic animals. [3] [4] Rocky shorelines are often found along exposed coastlines and provide habitat for a wide range of sessile organisms (Sessility (biology)), such as mussels, starfish, or barnacles, and various types of algae.
In physical oceanography, a shore is the widest strip geologically modified by the action of the past and present mass of water, while the beach is located at the edge of the shore, representing the intertidal zone when it exists. [5] Along tropical coasts with clear, nutrient-poor waters, coral reefs can often be found at depths of 1 to 50 meters.
According to an atlas prepared by the United Nations, about 44% of the human population lived within 150 km of the sea in 2013.[6] Due to their importance in society and their high population concentrations, coasts are important to large parts of the global food and economic system, and provide many ecosystem services to humanity. For example, important human activities take place in port cities. Coastal fisheries (commercial, recreational and subsistence) and aquaculture are important economic activities and create jobs, livelihoods and protein for most coastal human populations. Other coastal areas such as beaches and spas generate large income through tourism.
Coastal marine ecosystems can also provide protection from rising sea levels and tsunamis. In many countries mangroves are the main source of wood for fuel (e.g. charcoal) and construction materials. Coastal ecosystems such as mangroves and seagrasses have a much higher carbon sequestration capacity than many terrestrial ecosystems and can therefore play a critical role in the near future in helping to mitigate the effects of climate change by absorbing atmospheric anthropogenic carbon dioxide.