Glossary of Marine Biology

 

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Teleplanic larva. Larva capable of dispersal over long distances, such as across oceans

 

Temperate. Pertaining to the latitudinal belt between 23º 27' and 66º 33' north or south latitude

 

Tentacle-tube-foot suspension feeder. Suspension feeder that traps particles on distinct tentacles or tube feet (in echinoderms)

 

Terminal anchor. In hydraulically burrowing organisms: any device used to anchor the leading portion of the burrower, permitting muscular contraction to drag the rest of the body into the sediment

 

Territoriality. Defense of a specified location against intruders

 

Tertiary production. The production of living material per unit area (or volume) per unit time by organisms consuming the herbivores. Usually expressed as grams carbon per meter square per year

 

Thermocline. Depth zone within which temperature changes maximally

 

Thermohaline circulation. Movement of seawater that is controlled by density differences that are largely explained in terms of temperature and salinity

 

Tidal current. A water current generated by regularly varying tidal forces

 

Tides. Periodic movement of water resulting from gravitational attraction between the earth, sun, and moon

 

Top-down control. Refers to food webs where control of a population is mainly explained by consumption by a species or group of species at higher levels of the food chain (e.g., population change of population of mussels controled by seastar predation).

 

Trade winds. Persistent winds at low latitudes in both the Northern and Southern hemispheres, blowing toward the west and the equator

 

Trench. Deep and sinuous depression in the ocean floor, usually seaward of a continental margin or an arcuate group of volcanic islands

 

Trophic level. In a food chain, a level containing organisms of identical feeding habits with respect to the chain (e.g., herbivores)

 

Tropical. Being within the latitudinal zone bounded by the two tropics (23º 27' north and south latitude)

 

Turbidity. The weight of particulate matter per unit volume of sea water

 

Ultraplankton. Planktonic organisms that are less than 2 micrometers in size

 

Uniform spatial distribution. Situation in which individuals are more evenly spread in space than would be expected on the basis of chance alone

 

Upwelling. The movement of nutrient-rich water from a specified depth to the surface

 

Vents. See Hydrothermal vents

 

Vertically homogeneous estuary. An estuary in which, at any given location, wind or tidal mixing homogenizes salinity throughout the water column

 

Vitamin. Chemical substances required in trace concentrations acting as a cofactor with enzymes in catalyzing biochemical reactions

 

Viviparous (development). Refers to development of an organism through the juvenile stage within a parent

 

Wash zone. The depth zone in which sediments are disturbed by wave action near the shoreline

 

Water mass. A body of water that maintains its identity and can be characterized by such parameters as temperature and salinity

 

Watershed. The land area that is drained by a river or estuary and its tributaries

 

Westerlies (prevailing westerlies). Persistent eastward-equatorward winds in midlatitudes in both the Northern and Southern Hemispheres

 

Windward [side]. The side of an island that faces a persistent wind

 

Within-habitat comparison. A contrast of diversity between two localities of similar habitat type

 

Wrack zone. A bank of accumulated litter at the strandline

 

Year-class effect. The common domination of a species population by individuals recruited in one reproductive season

 

Zonation. Occurrence of single species or groups of species in recognizable bands that might delineate a range of water depth or a range of height in the intertidal zone

 

Zooplankton. Animal members of the plankton

 

Zooxanthellae. A group of dinoflagellates living endosymbiotically in association with one of a variety of invertebrate groups (e.g., corals)