| A | B |
|---|
| continental shelf | gradually sloping end of a continent that extends beneath the ocean |
| continental slope | ocean basin feature that dips steeply down from the continental shelf |
| abyssal plains | flat seafloor area from 4000 m to 6000 m below the ocean surface |
| mid-ocean ridge | area where new ocean floor is formed when lava erups through cracks in Earth's crust |
| trench | long, narrow, steep-sided depression in the seafloor formed where one crustal plate sinks beneath another |
| photosynthesis | food making process using light energy from the cun, carbon dioxide and water |
| pollution | introduction of wastes to an environmentm, such as sewage and chemicals, that can damage organisms |
| plankton | marine organisms that drift in ocean currents |
| nekton | marine organisms that actively swim in the ocean |
| benthos | marine plants and animals that live on or in the ocean floor |
| estuary | area where a river meets the ocean that contains a mixture of freshwater and ocean water and provides an important habitat to many marine organisms |
| reef | rigid,wave-resistant, ocean margin habitat built by corals from skeletal materials and calcium |
| chemosynthesis | food making process using sulfur or nitrogen compounds that is used by bacteria living near hydrothermal vents |
