NOAA's Coral Reef Data Discovery Glossary

This glossary will help the general seeker of coral reef data and information to understand the technical and scientific terminology used on the CoRIS Web site. Terms beginnng with letters L through Z appear on this page. Navigation is provided by first letter for all terms. Literature sources are listed in the References section at the bottom of the page.

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Landsat satellite - U.S. satellite used to acquire high-resolution (500-800m) remotely sensed multi-spectral images of the earth’s land surface and surrounding coastal regions

La Niña - a phenomenon characterized by unusually cold ocean temperatures in the eastern Equatorial Pacific, compared to El Niño, which is characterized by unusually warm ocean temperatures in the eastern Equatorial Pacific

larva - a sexually immature juvenile stage of an animal’s life cycle. However, there are a few exceptions, where the larval form never metamorphoses into the adult stage and is sexually mature (neoteny)

leeward - referring to the side of an island or reef that faces away from the prevailing wind

LIDAR (Light Detection And Ranging) - a remote-sensing technique that uses a laser light source to probe the characteristics of a surface target. A laser emission may be directed downward from a low flying aircraft. Information about the target is derived from back-scattered reflectance or fluorescence of the target. Chlorophyll pigments in coral reef organisms (e.g., algae, seagrasses, coral), when excited by shorter (blue or green) wavelength light, emit light at longer (red) wavelengths, i.e., it fluoresces

linear reef - a linear coral formation that is oriented parallel to the shore or the shelf edge

line intercept transect - a linear transect protocol where a tape is secured at each end of the transect with the tape draped over the reef in between. Observations are collected on each species and substrate component and their length under the tape

Lithothamnion ridge - a synonym for algal ridge. The algal genus Lithothamnion is important in maintaining reef integrity by cementing various pieces of calcium carbonate

long term monitoring -the repeated surveying of organisms, populations, communities, or environmental parameters over time to help us understand a variety of natural processes

lower palmata zone - the part of a reef crest that is seaward of the palmata zone. It consists primarily of elkhorn coral (Acropora palmata) at a depth of about 3-6 m in Caribbean reefs

macroalgae - algae that project more than one centimeter above the substratum

macrobenthos (macrofauna or macroflora) - benthic organisms (animals or plants) whose shortest dimension is greater than or equal to 0.5 mm

mangal - relating to a shoreline ecosystem dominated by mangrove trees, with associated mud flats

manta tow technique - a technique used to provide a general description of large areas of reef and to gauge broad changes in abundance and distribution of organisms on coral reefs. The technique, widely used in Australia, involves towing a snorkel diver (observer) at a constant speed behind a boat. The observer holds on to a ‘manta board’ attached to a small boat by a 17-meter length of rope. This person makes a visual assessment of specific variables during each manta tow (2 minutes duration), and records these data when the boat stops, on a data sheet attached to the manta board. The manta tow technique is used to provide a general description of large areas of reef and to gauge broad changes in abundance and distribution of organisms on coral reefs. The advantage of manta tow over other survey techniques is that it enables large areas of reefs to be surveyed quickly and with minimal equipment

mantle - a membranous or muscular structure in mollusks that surrounds the visceral mass and secretes a shell if one is present

mariculture - the cultivation of marine organisms under controlled conditions; a synonym for marine aquaculture

mass spawning - spawning events where many different species spawn simultaneously

mass spectrometer - a laboratory instrument that measures the mass-to-charge ratio of individual molecules that have been converted into ions. This information is then used to determine the masses of the molecules

massive colony - a coral colony that is solid and typically hemispherical in shape

maximum sustainable yield - the maximum number of a food or game population that can be harvested without harming the population's ability to grow back

meandroid colony - a massive colony that has corallite mouths aligned in valleys, such that there are no individual polyps

meiobenthos (meiofauna or meioflora) - benthic organisms whose shortest dimension is less than 0.5 mm but greater than or equal to 0.1 mm

mesoglea - the connective tissue layer between the epidermis and gastrodermis of cnidarians and ctenophores (comb jellies)

metamorphosis - change of body shape, e.g., the change from a larval form to a juvenile or adult form

microatoll - a circular colonial corallum up to 1 m height and 4 m diameter. Growth is mainly lateral, as upward growth is limited by aerial exposure

microbenthos (microfauna or microflora) - benthic organisms whose shortest dimension is less than 0.1 mm

microenvironment - a specific set of physical, biological, and chemical factors immediately surrounding the organism

microhabitat - a smaller part of a habitat that has some internal interactions allowing it to function self-sufficiently within a generally larger habitat, such as a patch reef in a lagoon

migration - the large-scale movement of a population for some specific purpose

mini-atoll - a ring-shaped patch reef with a central area (lagoon) containing sand

mixed layer - near-surface waters subject to mixing by wind and waves; there is little variation in salinity or temperature below the mixed layer

mixed zone - the populous region of most bank/barrier reefs seaward of the lower palmata zone. It begins at a depth of 6-8 m

MMM (Maximum Monthly Mean SST climatology) - the highest expected (climatological) monthly SST expected at all ocean locations based on 15 years of monthly mean SST data (serves as the input threshold for the Coral Bleaching HotSpot charts)

Mollusca - an animal phylum that includes bivalves, squids, octopuses and snails. They are distinguished by a muscular foot, a calcareous shell secreted by the underlying body wall (the mantle) and a feeding organ (the radula). Many species are common inhabitants of coral reefs

monoecious - having combined sexes. Individuals of monoecious species contain the reproductive systems of both males and females

monsoon - a periodic wind caused by the effects of differential heating, with the largest being the Indian monsoon found in the Indian Ocean and southern Asia

Montastraea - a genus of hard (stony) coral that includes the boulder coral and the great star coral

morphology - a branch of biology that deals with the form and structure of organisms, apart from their functions (physiology)

MPA (Marine Protected Area) - Executive Order 13158 defines a marine protected area (MPA) as “any area of the marine environment that has been reserved by Federal, State, territorial, tribal, or local laws or regulations to provide lasting protection for part or all of the natural and cultural resources therein.” MPAs are used as a management tool to protect, maintain, or restore natural and cultural resources in coastal and marine waters. There are many different types of MPAs in U.S. waters

MSS (Multispectral Scanner) - a scanner system that simultaneously acquires images of the same scene in various wavelength bands

mucus - a gelatinous material secreted by specialized mucous cells. In corals, it functions in protection from bacterial invasion, food capture, and removal of sediment particles. Mucus is usually moved by cilia (motile hair-like extensions of the cell membrane)

mud - a fine sediment often associated with river discharge and buildup of organic material in areas sheltered from high-energy waves and currents

mud flat - a relatively level area of fine silt along a shore (as in a sheltered estuary) or around an island, alternately covered and uncovered by the tide, or covered by shallow water

mutation - changes in the nature of single genes or segments of chromosomes, which are then inherited by successive generations

mutualism - a symbiotic interaction between two species in which both derive some benefit

natural climate record - a record of climatic events found by examining the natural environment (e.g., coral growth bands, tree rings, layers of ice in glaciers)

NESDIS (National Environmental Satellite, Data and Information Service) - the NOAA agency that operates and manages the U.S. civilian weather satellites and the national environmental data centers, such as the National Oceanographic Data Center (NODC), the National Climatic Data Center (NCDC), and the National Geophysical Data Center (NGDC)

niche - the role of an organism in an ecological community; the environmental requirements and tolerances of a species; sometimes seen as a species’ “profession” or what it does to survive

nutrient - any substance assimilated by organisms that promotes growth. Marine scientists typically measure nitrites, nitrates, phosphates, and silicates as nutrients for plant growth

ocean color - a term that refers to the spectral dependence of the radiance leaving a water body

ocean color sensor- an instrument for the remote sensing of ocean color, usually from aircraft or satellite

oceanic - associated with sea-water environment seaward of the shelf-slope break

oceanic reef - a reef that develops adjacent to deeper waters, often in association with oceanic islands

omnivore - an organism whose diet consists of a wide variety of foodstuffs, including plants and animals

oolitic limestone - rock composed primarily of petrified corals or the skeletons of other calcareous animals

opisthobranch - a marine gastropod, many of which have lost or reduced their shell, mantle and gills

oral disc - the area around the mouth of an anthozoan polyp that bears from eight to several hundred tentacles

outer slope - a synonym of reef slope. It is sometimes used to represent the lower reef slope

oxygen isotopes - oxygen atoms that have the same atomic number (protons) but different mass numbers (and different numbers of neutrons). The two stable isotopes of oxygen are ¹⁶O and ¹⁸O

oxygen isotope ratio ( 18O) - an expression for the ratio of the ¹⁸O to ¹⁶O atoms in a sample relative to a standard, defined as: d ¹⁸ O= (¹⁸O/¹⁶O sample - ¹⁸O/¹⁸O standard)/ ¹⁸O/¹⁶O standard

paleobiogeography - the distribution of organisms as revealed by the fossil record

paleoclimatology - the study of past climates throughout geological history, and the causes of the variations among them

paleoecology - the study of the relationship of extinct organisms or groups of organisms to their environments

paleoenvironmental proxy - an environmental remnant of the past (pollen grains, tree rings, lake sediments, pack rat middens, ice cores, coral skeletons) used to assist researchers in deciphering past climatic conditions

paleothermometer - a proxy that provides absolute estimates of past temperature. An example is the Sr/Ca ratio found in coral skeletons

paliform lobe - an upright skeletal rod or plate at the inner margin of septa formed by upward growth of the septum

palmata zone - the region of a reef crest of a bank or barrier reef that is closest to the water surface. It is composed almost completely of elkhorn coral (Acropora palmata) in the Caribbean

papillae - a rounded nipple-like projection covering the coenosteum; found in Montipora

PAR (Photosynthetically Active Radiation) - those wavelengths of light that can be absorbed by chlorophyll or other light harvesting pigments

patch reef - a coral boulder or clump of corals formed on a shelf, usually of less than 70 m depth, often in the lagoon of a barrier reef or atoll. It is unattached to a major reef structure

pavement - rock exposed at the Earth's surface in the form of a more or less horizontal surface, usually with crevices or joints

pedal disc - a disc at the aboral end of the body trunk used for attachment. A synonym of basal plate

pedal laceration - a type of asexual reproduction in some sea anemones in which parts of the pedal disc break off and are left behind as the anemone moves

Pelecypoda (Bivalvia or Lamellibranchia) - a class of Mollusca that includes clams, oysters and mussels

pentamerous - divided into five parts; a characteristic of the body plan of echinoderms

petaloid septa - primary septa which have a tapered or curved shape because they are enclosed by other septa

phaceloid coral - a coral that has corallites of uniform height which are adjoined toward their base

photic zone - the vertical zone in the ocean extending from the surface to that depth permitting photosynthetic activity

photo-quadrat - a quadrat that is photographed for purposes of later analysis and permanent record for species monitoring or measurement

photosynthesis - process by which autotrophic chlorophyll-containing organisms manufacture their own energy sources (simple sugars) from the intracellular chemical reaction of carbon dioxide and water in the presence of sunlight and chlorophyll. Oxygen is a photochemical byproduct of photosynthesis

photosynthetic pigment - a pigment that efficiently absorbs light within the 400-700 nm range and is essential for photosynthesis

phylum - a major division of a biological kingdom, consisting of closely- related classes; represents a basic fundamental pattern of organization and, presumably, a common descent

picture element - in a digitized image, this is the area on the ground represented by each digital value. Because the analogue signal from the detector of a scanner may be sampled at any desired interval, the picture element may be smaller that the ground resolution cell of the detector. It is commonly abbreviated as pixel

pinnacle reef - a nearly cylindrical reef with vertical sides; may be up to 200 m diameter and 50 m in height

pinnule - a side branch structure on the tentacle of soft corals, giving them a feathery appearance

plankton - the passively floating or weakly motile aquatic plants (phytoplankton) and animals (zooplankton)

plastid - a membrane-bound organelle in plant cells that functions in storage (of food or pigments) or food production. Chloroplasts contain the pigments for photosynthesis

platform reef - a large reef of variable shape lacking a lagoon, seaward of a fringing reef and/or a barrier reef, for which the width is more than half its length

Pleistocene epoch - an interval of the Quaternary period, from 1.8 million years before present to 10 thousand years before present

Pliocene epoch - an interval of the late Neogene period, from 5.3 to 1.8 million years before present

plocoid colony - a coral colony which has conical corallites with their own walls

PointCount - PointCount for Coral Reefs is a Windows/Win95-based program developed to utilize the random point count method to accurately estimate percent coverage of corals, sponges, and associated substrate from frame grabbed underwater video imagery

point intercept transect - a linear transect protocol where a tape is secured at each end of the transect with the tape draped over the reef in between. Observations are collected on each species and substrate component at specified points along the line

polar-orbiting satellite - a satellite traveling in a near-polar orbit around the globe; civilian satellite program managed and operated by NESDIS

polyclad flatworm - a free-living flatworm belonging to the order Polycladida (Class Turbellaria; Phylum Platyhelminthes). Many species are coral reef inhabitants

polyp bail-out - the dissociation and dispersal of coral polyps from adult colonies

population - a group of individuals of the same species living in the same area at the same time and sharing a common gene pool; a group of potentially interbreeding organisms in a geographic area

population dynamics - the study of the factors that affect the growth, stability, and decline of populations, as well as the interactions of those factors

Porites - an important and dominant genus of hermatypic coral. Porites brood or release live young rather than sperm and egg packets like most corals

potential coral reef bleaching episode - potential for coral bleaching occurs when the sea surface temperature is at least 1 degree C above the maximum expected summertime temperature

primary productivity - the rate at which new plant biomass is formed by photosynthesis. Gross primary productivity is the total rate of photosynthetic production of biomass; net primary productivity is gross primary productivity minus the respiration rate

producers - the first level in a food pyramid; usually consist of photosynthetic organisms that generate the food used by all other organisms in the ecosystem

prokaryotic - descriptive of organisms with cells possessing no distinct nucleus. Prokaryotes include bacteria and cyanobacteria

prostrate colony - a coral colony which sprawls horizontally over the substrate

protandry - a state in hermaphroditic systems characterized by the development of male reproductive organs, or maturation of their gametes, before the appearance of the corresponding female product, thus insuring against self-fertilization

protogyny - a state in hermaphroditic systems characterized by the development of female reproductive organs, or maturation of their gametes, before the appearance of the corresponding male product, thus insuring against self-fertilization

proxy signal - paleoclimatic evidence that can be used to indirectly infer or estimate some aspect of the paleoenvironment, such as precipitation or temperature

Quaternary period - the second period of the Cenozoic era containing the Pleistocene epoch and the Holocene epoch, and dating from 1.8 million years to the present

radial corallite - a corallite on a side of a branch as opposed to an axial corallite on the tip of the branch

radii - inconspicuous septal elements which connect septa with the columella

radiocarbon age - the age of plant or animal remains, determined by measuring the remaining activity of the ¹⁴C atoms in the sample: A=A₀e^-t where A is the measured activity, A₀ is the initial activity, e is the decay constant, and t is the sample age

radiocarbon dating - a dating method used to determine the age of samples containing carbon. The method measures the disintegration of the ¹⁴C atom. ¹⁴C is produced in the atmosphere by cosmic ray bombardment, and has a half-life of 5,570 years, making it useful for dating samples in the range of 0-40,000 years

radiocarbon time - regular known rates of radiocarbon decay that are used to determine the exact ages of carbon-based life

rampart - a narrow ridge, 1-2 m high, built by waves along the seaward edge of a reef flat. It consists of boulders, shingle, gravel or reef rubble, commonly capped by dune sand

random sample - a sample in which each individual in a population has the same chance of being selected as any other

raster - an abstraction of the real world where spatial data is expressed as a matrix of cells or pixels, with spatial position implicit in the ordering of the pixels. With the raster data model, spatial data is not continuous but divided into discrete units. This makes raster data particularly suitable for certain types of spatial operation. The term may also refer to the region of a CRT (cathode-ray tube) or LCD (liquid crystal display) monitor that is capable of rendering images

real time - time in which reporting of events or recording of events is simultaneous with the event

recruitment - the influx of new members into a population by reproduction or immigration

reef base - the area below the consolidated slope extending up to 1 km but no deeper than 50 m. A synonym of talus slope

reef block - a large, isolated rock section that has been displaced from the reef platform, reef margin, reef front zones or the non-calcium carbonate bedrock, usually resulting from storm waves

reef crest - the sharp break in slope at seaward margin or edge of reef flat

reef flat - the shallow area between the shoreline intertidal zone and the reef crest of a fringing reef

reef mound - a structure that lacks reef characteristics, such as diversification and domination stages

reef rubble - dead, unstable coral pieces often colonized with macroalgae. This habitat often occurs landward of well developed reef formations in the reef crest or back reef zone

remote sensing - the collection of information about an object or event without being in physical contact with the object or event. Remote sensing is restricted to methods that record the electromagnetic radiation reflected or radiated from an object, which excludes magnetic and gravity surveys that record force fields

remote sensing tool - an instrument used in remote sensing often combined with a geographic information system to provide synoptic and objective views and data of the environment

reproductive isolating mechanism - a mechanism that prevents reproduction from occurring between two populations. Pre-zygotic reproductive isolating mechanisms (which take effect before fertilization) include environmental, temporal, behavioral, mechanical, and physiological barriers that prevent individuals of different populations from producing viable progeny. Post-zygotic reproductive isolating mechanisms (which take effect after fertilization) include gamete incompatibility, hybrid inviability, and hybrid sterility

reproductive isolation - a species is an interbreeding natural population that is reproductively isolated from other such groups. Species are usually separated by discontinuities, which constitute barriers that prevent, or at least inhibit, an interspecific gene flow and gene exchange. Establishment of reproductive isolation is essential for development of a new species

resolution - the ability to distinguish closely spaced objects on an image or photograph. It is commonly expressed as the spacing, in line-pairs per unit distance, of the most closely spaced lines that can be distinguished

respiration - a biochemical process by which living organisms take up oxygen from the environment and consume organic matter, releasing both carbon dioxide and heat energy

ribbon reef - a large offshore linear reef, seaward of a fringing reef, which is linear but does not form a barrier to the land. A synonym of shelf-edge reef and sill reef

rubble zone - the shallowest part of a reef crest landward of the palmata zone. It consists of broken pieces of coral washed back by storms

sampling - the probabilistic, systematic, or judgmental selection of a sub-element from a larger population, with the aim of approximating a representative picture of the whole

sampling bias - the tendency of a sample to exclude some members of the sampling universe and over-represent others

sampling unit - the sub-element of the total population selected for sampling

sampling universe - the largest entity to be described, of which the sample is a part

sand - coarse sediment typically found in areas exposed to currents and wave energy

satellite colony - a colony that develops within the tissue of a parent colony and which has its own unattached skeleton

satellite imagery - a representation of the measurement of energy emitted or reflected by the Earth in a variety of wavelengths. Earth observation imagery takes a number of forms, of which the most traditional are optical and near-infrared radiation, from about 0.4 (blue) to 2.0 (IR) micrometers. Apart from visual and near-infrared, other bands of the spectrum commonly used include thermal infrared (heat) and microwave (radar). Each of these has its own applications

scale-like corallites - corallites that form a pattern which resembles fish scales

science - a method of learning about the physical universe by applying the principles of the scientific method, which includes making empirical observations, proposing hypotheses to explain those observations, and testing those hypotheses in valid and reliable ways; also refers to the organized body of knowledge that results from scientific study

scientific name - the Linnaean binomial. A name of a species composed of two words: the genus (or generic) name and the species (or trivial) name, e.g., Acropora palmata. The scientific name is always written in italics. The first letter of the generic name is always capitalized; that of the species name is never capitalized

sclerosepta - the radiating calcareous partition in the corallite of stony corals

SCUBA (Self-Contained Underwater Breathing Apparatus) - a diving mode independent of surface air supply in which the diver uses open circuit self-contained underwater breathing apparatus which supplies air or breathing gases at ambient pressure

sea snake - a member of the family Hydophiidae. Sea snakes are common in the Indo-Pacific. Related to cobras, these live-bearing reptiles are highly venomous but not aggressive by nature

seaward slope - the area of a barrier reef or atoll from the reef crest. It includes spurs, grooves, terraces, reef walls, etc.

SeaWiFS - Sea-viewing Wide Field-of-view Sensor carried on the SeaStar satellite

Secchi depth - the depth at which a Secchi disk disappears from view as it is lowered in water

Secchi disk - a white disk 20-30 cm in diameter, used as a qualitative way of measuring water clarity. It is lowered from a vessel and viewed from above the surface in full solar illumination to estimate the light attenuation in the water column. This is done empirically by relating the depth at which the disk disappears to the attenuation of light

secondary production - the production of living material per unit area (or volume) per unit time by herbivores. It is usually expressed as grams carbon per meter square per year

sensor - a device that receives electromagnetic radiation and converts it into a signal that can be recorded and displayed as numerical data or as an image

sessile - describes an immobile organism because of its attachment to a substrate. The term has also been applied to organisms, such as anemones, that move very slowly

seston - minute particulate material moving in water that is composed of both living organisms, such as plankton, and non-living matter such as plant debris and suspended soil particles

shelf escarpment - the edge of the bank/shelf where depth increases rapidly into deep oceanic water

shelf reef - a reef that forms on the continental shelf of large land masses

shoal - a submerged expanse of coral reef, surrounded by deep water, which does not form a part of a barrier or fringing reef

sibling species - closely-related species that are nearly morphologically indistinguishable

Sipuncula - an animal phylum that contains the peanut or starworms. They are small, non-segmented benthic animals (they are not worms), some of which live in coral crevices, empty mollusk shells or marine worm tubes. Several species bore into coralline rock

skeletal density - certain massive coral species (e.g. Porites) exhibit annual variations in the density of their calcium carbonate (CaCO3) skeleton, similar to tree rings. The annual density bands are revealed when slices of coral skeleton are X-rayed

slug - a pulmonate or opisthobranch gastropod in which the shell is absent, or reduced and buried within the mantle

solar radiation - the amount of radiation or energy received from the sun at any given point

Southern Oscillation - a large-scale atmospheric and hydrospheric fluctuation centered in the equatorial Pacific Ocean. It exhibits a nearly annual pressure anomaly, alternatively high over the Indian Ocean and high over the South Pacific. Its period is slightly variable, averaging 2.33 years. The variation in pressure is accompanied by variations in wind strengths, ocean currents, sea-surface temperatures, and precipitation in the surrounding areas. El Niño occurrences are associated with the phenomenon

spat - tiny single corallites that form immediately after the metamorphosis of planula larvae

spatial index - the ratio of reef surface contour to linear distance. As part of a monitoring program employing a chain transect protocol, the spatial index provides a way to quantify changes in the topographical complexity of the reef

spawn - to produce or deposit eggs; the eggs of aquatic animals; offspring in great numbers or masses; to give forth young in large numbers

species - in sexually reproducing organisms, a species is a group of genetically related organisms, usually similar in physical appearance, that actually or potentially interbreed and are reproductively isolated from other groups

species diversity - the number of different species in an area and their relative abundance

species richness - the number of species in an area or biological collection

split spawning - spawning occurring over consecutive nights or consecutive lunar cycles within a reef

spur and groove - A system of shallow ridges (spurs) separated by deep channels (grooves) oriented perpendicular to the reef crest and extending down the upper seaward slope

SST (Sea Surface Temperature) - the temperature of the layer of seawater (approximately 0.5 m deep) nearest the atmosphere

stable isotope - an isotope of a chemical element which is not spontaneously radioactive. Elements can exist in both stable and unstable (radioactive) forms. Most elements of biological interest (including C, H, O, N, and S) have two or more stable isotopes, with the lightest of these present in much greater abundance than the others. Among stable isotopes the most useful as biological tracers are the heavy isotopes of carbon and nitrogen. These two elements are found in the earth, the atmosphere, and all organisms

statistical analysis - the application of probability theory to quantified descriptive data

stolon - in corals, a horizontal polyp outgrowth from which daughter polyps are budded

stratigraphy - the branch of geology that deals with the origin, composition, distribution and succession of strata

stromatolite - a layered, fossilized deposit, mainly of limestone, formed by photosynthesizing colonial cyanobacteria and other microbes. They are the oldest known fossils, dating back more than 3 billion years. Stromatolites are prokaryotes that thrived in warm aquatic environments and built reefs much the same way as coral does today. They were common in Precambrian time (i.e., more than 540 million years ago). Although stromatolites continue to form in certain areas of the world today, they grow in greatest abundance in Shark Bay in western Australia

submarine groove - a trough-like depression with vertical to overhanging walls which cut across the reef front at right angles

subspecies - a taxonomic subdivision of a species; a population of a particular region genetically distinguishable from other such populations and capable of interbreeding with them

substrate - the material making up the base upon which an organism lives or to which it is attached

surge channel - a deep channel in the windward side of a coral reef through which water moves in and out of the reef

suspension feeder - an organism that feeds by capturing particles suspended in the water column. A synonym of filter feeder

sweeper polyp - a polyp that acts in an aggressive manner by stinging neighboring corals and sessile invertebrates

sympatric species - different species that live in the same area but are prevented from successfully reproducing by a reproductive isolating mechanism

synecology - the branch of ecology that deals with whole communities and the interactions of the organisms within them

synonym - in taxonomy, one of two or more scientific names that are spelled differently, but refer to the same organism

table reef - an isolated flat-topped coral reef which reaches the surface but lacks a lagoon

taxonomy - the science and methodology of classifying organisms based on physical and other similarities. Taxonomists classify all organisms into a hierarchy, and give them standardized Latin or Latinized names. There are seven main levels of classification in the hierarchy. They are, from most to least inclusive: Kingdom; Phylum (or Division for algae, fungi, and plants); Class; Order; Family; Genus; and Species. Taxonomists describe new species, classify organisms, and study speciation, the evolution of new species

tentacle-tube-foot suspension feeder - a suspension feeder that traps particles on distinct tentacles or tube feet (in echinoderms)

terpenoid - a class of organic compound produced by soft corals for defense and for aggressive colonization of new substrates

thermohaline circulation - the density-driven convective circulation system of the world’s oceans. Warm Atlantic water moves northward along the axis of the Gulf Stream, and evaporation increases water density while releasing heat to the colder atmosphere in the North Atlantic. Once significantly dense, the water sinks into the deep ocean, forming a downward limb of a giant conveyor-like circulation that extends around the world’s oceans

tide - the periodic rising and falling of the water that results from the gravitational attraction of the moon and sun acting on the rotating earth

TIFF (Tag Image File Format) - a common format for exchanging raster graphics (bitmap) images between application programs, including those used for scanner images

trade winds - a system of relatively constant low level winds that occur in the tropics. The trade winds blow from the northeast to the equator in the Northern Hemisphere and from the southeast to the equator in the Southern Hemisphere

trochophore - a type of larva found in annelids, mollusks, echiurans and other invertebrate groups. They are characterized by having the larval body ringed with a girdle of cilia ( the prototroch) and possessing a tuft of cilia at the apical end

trophic level - a classification system of organisms according to their means of obtaining nutrition. A segment of the food chain in which all organisms obtain food and energy in basically the same manner (e.g., photosynthesis, herbivory, or carnivory) and in which all organisms are the same number of links from the photosynthetic segment

Tropical Ocean Coral Bleaching Indices - indices of selected coral reef sites/regions (maintained by NOAA/NESDIS) that present satellite- obtained measurements of relevance to coral reef ecosystems

upwelling - the process by which warm, less-dense surface water is drawn away from a shore by offshore currents and replaced by cold, denser water brought up from the subsurface

Urochordata (Tunicata) - a subphylum of the animal phylum Chordata that contains the ascideans (sea squirts). Most adults are sessile and bear little resemblance to the other chordates. They are common inhabitants of coral reefs and mangrove roots

U.S. Coral Reef Task Force (USCRTF) - established by President Clinton in June, 1998, through Executive Order 13089 on Coral Reef Protection, to lead the U.S. response to this growing global environmental crisis. Chaired by the Secretary of the Interior and the Secretary of Commerce, the USCRTF is composed of the heads of 11 federal agencies and the Governors of 7 states, territories or commonwealths with responsibilities for coral reefs. The USCRTF is responsible for overseeing implementation of the Executive Order, and developing and implementing coordinated efforts to: map and monitor U.S. coral reefs; research the causes and solutions to coral reef degradation; reduce and mitigate coral reef degradation from pollution, overfishing and other causes; and implement strategies to promote conservation and sustainable use of coral reefs internationally

UV (ultraviolet) radiation - the region of the electromagnetic spectrum consisting of wavelengths from 1 to 400 nm

vector - an abstraction of the real world where positional data is represented in the form of coordinates. In vector data, the basic units of spatial information are points, lines and polygons. Each of these units is composed simply as a series of one or more coordinate points. For example, a line is a collection of related points, and a polygon is a collection of related lines. Vector images are defined mathematically as a series of points joined by lines. Vector-based drawings are resolution independent. This means that they appear at the maximum resolution of the output device, such as a printer or monitor. Each object is self-contained, with properties such as color, shape, outline, size, and position on the screen

veliger - a molluskan larva in which the foot, mantle and shell first make their appearance

veneer reef - a reef with very little calcium carbonate accretion. A non-reef coral community

verruca (pl. verrucae) - a small cylindrical projection arising from the corallum that contain calices; found in Pocillopora

video transect - a nondestructive, repeatable procedure for assessing and monitoring diurnally active fishes and other macroscopic marine organisms. Videotaping along a linear transect reduces the variance in error inherent with visual observations made by a diver or snorkeler, and allows virtually unlimited time for study of the images by many individuals

visible radiation - energy at wavelengths from 400 - 700 nm that is detectable by the human eye

Vitareef program - a program that was established in order to provide a standardized method of characterizing the conditions of reef corals. It can and has been used by both researchers and non-scientists to document observations of reefs at specific points in time, which can be followed up in subsequent observations to assess changes in the state of individual coral colonies, selected coral species, or a reef as a whole

water column - the open-water environment, distinct from the sea bed or shore, which may be inhabited by swimming organisms

water vascular system - in echinoderms, a system of internal canals and appendages that are water-filled and functions as a means of locomotion

wavelength - the distance between successive wave crests or other equivalent points in a harmonic wave

weather - temperature, precipitation, and wind speed and direction that occur on a daily basis

white skeleton - the exposed white calcium carbonate skeleton of a coral colony

windward - refers to the side of an island or reef that faces the prevailing wind

worm reef - a massive structure composed of clusters of oval, table-like mounds constructed by marine polychaete worms in the family Sabellariide. They consist of all sorts of sediments consolidated by a mucoprotein cement produced by the worm. This reef may start in the intertidal zone and extend into the subtidal zone. Some are in deeper water. Unlike the colorful and ornate coral reefs, worm reefs are drab, monotonous and rounded clusters, mounds and platforms that grow upward and outward from the durable substrate from which their colonies develop. Worm reefs offer several ecological benefits. They provide feeding and browsing grounds for a diverse community of marine organisms and an ideal home for attaching plants, sponges and shelter-seeking animals. Also, unlike coral reefs, worm reefs are not restricted to the tropics

zonation - the 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

zone - a large-scale physical feature within the ecosystem. Reef zones are determined by currents, wave surge, exposure to sunlight and water depth, and may be comprised of a number of habitats

zooid - a tubular, oval or box-like structure that contains a lophophore, a circular or horseshoe-shaped fold of the body wall that encircles the mouth and bears numerous ciliated tentacles. Most species form erect or encrusting colonies. They occur in many different habitats, including coral reefs

zygote - a fertilized egg with the diploid number of chromosomes formed by the union of the nuclei of male and female gametes

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References

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Farabee, M.J. 2001. Online Biology Book. Avondale, AZ: Estrella Mountain Community College.
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Global Change Glossary. Accessed January 2002. Oakland, CA: Pacific Institute for Studies in Development, Environment, and Security.
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Kaplan, E.H., 1982. A Field Guide to Coral Reefs - Caribbean and Florida. The Peterson Field Guide Series. Boston and New York: Houghton Mifflin Co.

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Levinton, J. Glossary of Marine Biology. Accessed January 2002. From: Marine Biology: Function, Biodiversity, Ecology. New York: Oxford University Press.
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N.J. McCormick and C.D. Mobley. Accessed January 2002. Optical Oceanography Glossary. Seattle, WA: Univ. of Washington.
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NOAA/NODC. 2001. Coral Reefs and Adjacent Ecosystems Website. Silver Spring, MD: NOAA
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Senese. F., 2001. General chemistry Glossary. Frostburg, MD: Frostburg State Univ.
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Vernon, J. and M. Stafford-Smith, 2000. Corals of the World. Townsville, Queensland: Australian Institute of Marine Science.

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Glossary of Terminology:L through Z

Glossary of Terminology:
L through Z