Pelagic zone

Any water in a sea or lake that is neither close to the bottom nor near the shore can be said to be in the pelagic zone. The word "pelagic" is derived from Greek πέλαγος (pélagos), meaning "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes from the surface of the sea almost to the bottom. Conditions differ deeper in the water column such that as pressure increases with depth, the temperature drops and less light penetrates. Depending on the depth, the water column, rather like the Earth's atmosphere, may be divided into different layers.

The pelagic zone occupies 1,330 million km³ (320 million mi³) with a mean depth of 3.68 km (2.29 mi) and maximum depth of 11 km (6.8 mi). Fish that live in the pelagic zone are called pelagic fish. Pelagic life decreases with increasing depth. It is affected by light intensity, pressure, temperature, salinity, the supply of dissolved oxygen and nutrients, and the submarine topography, which is called bathymetry. In deep water, the pelagic zone is sometimes called the open-ocean zone and can be contrasted with water that is near the coast or on the continental shelf. In other contexts, coastal water not near the bottom is still said to be in the pelagic zone.

Costa Rica

Coordinates: 10°N 84°W / 10°N 84°W / 10; -84

Costa Rica (ⁱ/ˌkoʊstə ˈriːkə/; Spanish: [ˈkosta ˈrika]; literally meaning, "Rich Coast"), officially the Republic of Costa Rica (Spanish: República de Costa Rica), is a country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west, the Caribbean Sea to the east, and Ecuador to the south of Cocos Island. It has a population of around 4.5 million, of whom nearly a quarter live in the metropolitan area of the capital and largest city, San José.

Costa Rica was sparsely inhabited by indigenous people before coming under Spanish rule in the 16th century. It remained a peripheral colony of the empire until independence as part of the short-lived First Mexican Empire, followed by membership in the United Provinces of Central America, from which it formally declared sovereignty in 1847. Since then, Costa Rica has remained among the most stable, prosperous, and progressive nations in Latin America. Following a brief but bloody civil war, it permanently abolished its army in 1949, becoming the first of only a few sovereign nations without a standing army.