Term | Definition |
epipelagic zone | The area of the water column that extends from the surface down to about 200 m (650 ft) |
pelagic zone | division of the ocean that represents all the water in the ocean with the exception of a thin layer on the bottom floor |
photic zone | a layer of the ocean's surface into which light can penetrate to allow for photosynthesis |
neritic zone | epipelagic water lying over the continental shelf |
oceanic zone | epipelagic water lying over the all of the ocean except for the continental shelf |
phytoplankton | organisms that are so powerfully productive that they can make food for themselves, organisms in their community, and other communities too |
micrometer | one-millionth of a meter |
holoplankton | species of zooplankton that spend their entire lives as plankton |
meroplankton | species of zooplankton that spend only part of their lives as members of the plankton community |
nekton | marine organisms that swim strongly enough to move against the ocean current |
planktivorous | marine organisms that feed only on zooplankton |
drag | waters tendency to resist the motion of objects |
buoyancy | a flotation strategy to help nektonic organisms stay afloat |
neuston | planktonic organisms living at the sea surface |
countershading | a method of camouflage in which an organism's coloration is darker on the upper side and lighter on the underside of the body |
myoglobin | a protein that provides more oxygen availability and gives the inside layer of muscle a darker color |
vertical migration | daily movement of small marine animals between the photic zone and lower depths |
dissolved organic matter (DOM) | organic material dissolved in ocean water |
microbial loop | the flow of energy in the epipelagic beginning with the phytoplankton, dissolved organic matter, and the smallest zooplankton, making energy available to the major food web |
thermocline | a thin but distinct layer in a large body of water in which temperature changes more rapidly with depth than it does in the layers above or below |
overturn | the process where cool winter temperatures cause the water of the surface layer to become colder & denser. this causes the water to sink & displaces the water in the deep layer, causing it to move upward. |
upwelling | the process that carries colder, nutrient-rich water upward to a more shallow depth |
Southern Oscillation | barometric pressure changes between the Pacific Ocean & Indian Ocean |
El Nino | a change in the surface currents on the Peruvian and Chilean coasts of South America resulting in coastal upwelling, bringing large quantities of nutrients up into the epipelagic zone |