Occurs when a coral becomes stressed and expels most of its colorful algae, leaving an underlying ghostly white skeleton of calcium carbonat.
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.
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.
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).