Occurs when a coral becomes stressed and expels most of its colorful algae, leaving an underlying ghostly white skeleton of calcium carbonat.
Strongly swimming organisms found in aquatic systems.
Warm, nutrient-rich, shallow part of the ocean that extends from the high-tide mark on land to the edge of a shelflike extension of continental land masses known as the continental shelf.
Land along a coastline, extending inland from an estuary, that is covered with salt water all or part of the year. Examples are marshes, bays, lagoons, tidal flats, and mangrove swamps.
The lower end of a river, where it meets ocean. Saltwater and freshwater mix here. Estuaries are known to be very productive.
The area of shore between the high-tide and low-tide lines.
Long, thin, low offshore islands of sediment that generally run parallel to the shore along some coasts.
Upper layer of a body of water through which sunlight can penetrate and support photosynthesis.
The portion of the ocean floor where light does not penetrate and where temperatures are cold and pressures intense.
The organic debris (plankton, dead organisms, fecal material, etc.) that "rains" into the dark area of the oceanic province from the lighted region above; the primary food of most organisms that live in the ocean's depths.
In a lake, the well-lit, open surface waters farther from shore.
Deepest, coldest area of a large lake with little light and limited biodiversity.
Bottom of an aquatic ecosystem; consists of sand and sediment and supports its own community of organisms.
A condition of a lake or other body of water characterized by low nutrients, low productivity, and high oxygen levels in the water column.
A condition in a lake or other body of water that is characterized by lush phytoplanktonic growth followed by high amounts of decay in the bottom resulting in depletion of oxygen in the water column.
Land area that delivers water, sediment, and dissolved substances via small streams to a major stream (river).
A wetland ecosystem in which shrubs and trees grow.
A treeless wetland ecosystem where plants such as grasses grow.
The sharp increase in water depth at the edge of the continental shelf separates the coastal zone from the vast volume of the ocean.