continental shelf gradually sloping end of continental slope extends from the outer a continent that begins edge of the continental at the shoreline and shelf down to the ocean extends out under the floor. ocean.

trench long, narrow, steep- abyssal plain flat seafloor areas from sided depressions that 4,000 m to 6,000 m form at a subduction below the ocean surface zone when one crustal that are formed when plate is forced under valleys are filled in by another. sediment. chemosynthesis using sulfur or nitrogen mid-ocean ridge an area at the bottom compounds as an energy of an ocean basin where source to produce food, plates separate allowing instead of using light hot magma from Earth’s from the sun interior to form new ocean floor. reef a rigid, wave resistant plankton marine organisms that structure built by corals drift with the currents from skeletal materials,

ocean basin low area of earth that is nekton animals that actively filled with water swim rather than drift with the currents.

estuary an area where the benthos plants and animals living mouth of a river opens on or in the seafloor. into an ocean. They contain saltwater and freshwater

The Trieste deep sea vessel that Mariana Trench Deepest place in the Pacific dove into the Mariana Ocean Trench in 1960

placer deposits deposits found at the seamount underwater, inactive mouth of rivers in volcanic peaks. These coastal regions. are most commonly found in the Pacific Ocean.

buoyancy how easily an organism food web a complex system of sinks or floats. Nekton overlapping food chains. need to be able to control their buoyancy to swim.

ecosystem a community of phytoplankton one-celled organisms organisms and their that live in the upper environment. layers of ocean where they can get sunlight to do photosynthesis

habitat the area of the tide pool a characteristic of environment where a rocky shores. These are plant or animal normally formed when water lives. remains on shore, trapped by the rocks during low tide. bioluminescence This process is used by pollution The introduction of some marine organisms harmful waste products, including some types of chemicals, and other bacteria, one celled substances not native to algae, and fish to make an environment light. algal bloom sewage dumping can act consumers organisms that feed on like fertilizer allowing producers and cannot algae to reproduce make their own food rapidly.

hydrothermal underwater openings manganese nodules small, darkly colored vents where hot water lumps strewn across (400°C) spurts from large areas of the ocean cracks in the rock on basins the ocean floor.

tube worms Animals discovered by producer organisms that undergo hydrothermal vents that photosynthesis. were thriving in the complete absence of light by using sulfur compounds