Biodiversity of Marine Ecosystems

The water covers about 71% of the earth's surface and occupies an area of about 361 million km2 and a volume of about 1370 million km3 of water. Oceans and seas are responsible for maintaining the global climate by regulating air temperature and supplying moisture for rainfall. They play a major part in the global carbon cycle, removing almost 25% of the carbon dioxide released by human activity. Furthermore, life would not have begun on Earth without seas, which support the planet's highest biodiversity. They also offer social and economic goods and services, as well as tourism and recreation, maritime transportation, security, and coastal protection. Marine ecosystems include the open ocean, the deep-sea ocean, and coastal marine ecosystems, each of which has different physical and biological characteristics. The variability of the marine ecosystem is the result of the wide array of habitats in seas and oceans. Coral reefs, seagrasses, estuaries, and mangroves are the most important types of marine ecosystems. Variations in the characteristics of the marine environment create different habitats and influence what types of organisms will inhabit them. The marine environment can be divided into zones based on physical features such as depth, temperature, light penetration, and other several factors. There are two main marine realms or provinces, a pelagic realm that includes the water column and a benthic realm that represents the sea floor. Each of these two domains has also been divided into other smaller domains or regions based on the prevailing environmental conditions. Pollution, habitat alteration, and overfishing are the most destructive impacts on the marine environments and their threats are very clear. So, marine ecosystems in oceans and seas should be protected through planned management in order to prevent the over-exploitation of these resources.