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Oceans and seas

Observed from space, our planet’s surface appears to be dominated by the color blue. This blue color occurs because of the presence of the oceans and seas of the world. These features cover approximately 71% or 361 million square kilometers (139 million square miles) of Earth’s surface with a volume of about 1370 million cubic kilometers (329 million cubic miles). The average depth of these bodies of seawater is about 3.8 kilometers (2.4 miles). Maximum depths can exceed 10 kilometers (6.2 miles) in areas known as ocean trenches. The oceans contain 97% of our planet's available water. The ocean is also home to many forms of life uniquely adapted to survive in this habitat. Humans have degraded the oceans and their life through pollution, overfishing, carbon dioxide acidification and resource exploitation.

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Recently Updated
Spinner dolphin Last Updated on 2014-04-17 17:28:05 The Spinner dolphin (Stenella longirostris), a marine mammal in the family of oceanic dolphins,  gets its name from the spinning behavior it shows when it leaps out of the water. This cetacean species lives in schools showing a dominance hierarchy and displays complex interactions among individuals. S. longirostris also engages in intricate echolocation underwater acoustics. Spinner dolphins attract tourists for dolphin watching. The species is of special interest for scientific investigation because of its remarkable capacity to learn.   Conservation Status: Data Deficient Scientific Classification Kingdom: Animalia Phylum:--- Chordata Class:------ Mamalia Order:-------- Cetacea Family:-------- Delphinidae Genus:--------- Stenella Species:--------Stenella longirostris... More »
Orca Last Updated on 2014-04-16 15:11:43 Orcinus orca, or simply orca, is in fact the largest of the dolphins within the order of cetaceans. This species of marine mammal, also commonly known as the killer whale, is easily identified by its black and white coloration; the underside is white with white patches behind the eyes and a greyish white area called a saddle-patch behind the dorsal fin. The shape of the saddle is unique in each animal, and can help to identify individuals. The dorsal fin is also used to recognize individuals. Male orcas have the tallest dorsal fin known in the animal kingdom, measuring up to six feet high in mature males.  Females have shorter, more curved dorsal fins.  Conservation Status:  Data Deficient Scientific Classification Kingdom: Anamalia (Animals) Phylum:--- Chordata Class:------ Mammalia... More »
Madagascar mangroves Last Updated on 2014-04-15 15:37:23 Shielded from monsoon winds by the central mountains of Madagascar, Madagascar mangroves occupy a wide range of environmental and climatic conditions along the western coastline along the Indian Ocean. Although the ecoregion’s species richness is low, it is unusual in supporting certain endemic tree species. The mangroves also shelter highly diverse mollusk and crustacean communities, while capturing sediment that threatens coral reefs and seagrass beds. Birds, sea turtles, and dugongs all utilize mangroves, as do the Malagasy people. Rice farming, shrimp aquaculture and construction materials are all carried out within these mangroves. On Madagascar, mangroves are found primarily along the western coast. They occur in a wide range of environmental and climatic conditions, fostered by a low coastal platform, high tidal range, and a constant freshwater supply from numerous... More »
East African mangroves Last Updated on 2014-04-15 15:07:48 Highly productive nurseries for fish and prawns, eastern African mangroves significantly enhance the biodiversity of surrounding marine habitats while providing vital habitat for migratory birds, marine turtles, dugongs and porpoises. The most developed mangroves in this ecoregion extend as far as 50 kilometers (km) inland, with canopy heights up to 30 meters (m). However, Eastern African mangroves are threatened in many areas by overuse and conversion by a growing human population that utilizes the mangroves for rice farming, shrimp aquaculture, and for construction materials and the timber trade. Eastern African mangroves encompass mangrove areas found in Mozambique, Tanzania, Kenya, and Somalia. The dominant climatic influences on most of the region are the seasonal wind patterns, associated with the Northeast monsoon (NEM) and the Southeast monsoon (SEM), which blow towards... More »
Pan-tropical spotted dolphin Last Updated on 2014-04-12 15:29:32 The Pantropical spotted dolphin (Scientific name: Stenella attenuata) is a marine mammal within the family of ocanic dolphins, part of the order of cetaceans, that is found in all the world's oceans between about 40°N and 40°S. The gregarious Pantropical spotted dolphin forms schools that can range in size from less than one hundred to thousands of individuals. The pantropical spotted dolphin is well known for its tendency to associate with schools of tuna in this region. While this may be due to an overlap in diet, other reasons for this association have also been suggested, such as increased protection from predators, as there is safety in numbers. As a result of this association, Pantropical spotted dolphin have been frequently killed in as a bycatch in the fishing of yellowfin tuna with purse-seine nets. The pantropical spotted dolphin is a fast swimmer that... More »