Glossary of Terminology:
A through K

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 A through K 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.

Crown-of-Thorns starfish (Acanthaster sp.), a voracious predator of corals.

acanthocaulus - a juvenile coral of some species that is attached to the substrate either directly or on a stalk

accretion - growth by virtue of an increase in intercellular material

acolonial coral - a solitary coral that does not form a colony

acontium - a thread-like part of a coral polyp’s or anemone’s digestive system and employed as defensive or aggressive structures when extruded

Staghorn coral (Acropora sp.).

acrorhagus - a sac, covered with nematocysts, that protrudes from below the sweeper tentacles or on the column of certain anthozoans

adaptation - changes in gene frequencies resulting from selective pressures being placed upon a population by environmental factors. This results in a greater fitness of the population to its ecological niche

adaptive radiation - the evolution of a single evolutionary stock into a number of different species

aerial photography - photographs taken from an aircraft or satellite utilized to interpret environmental conditions and geographic features

agonistic behavior - aggressive, negative behaviors, such as fighting, threatening, and fleeing

AGRRA (Atlantic and Gulf Rapid Reef Assessment) - an international collaboration of scientists and managers aimed at determining the regional condition of reefs in the Western Atlantic and Gulf of Mexico

ahermatypic coral - a coral that lacks zooxanthellae and does not build reefs

algae - unicellular, multicellular, solitary or colonial plants that contain chlorophyll. They lack roots, stems, leaves, flowers, and seeds

Coralline algae makes up part of an algal reef.

algal reef - a reef, usually exposed to wave action, composed of coralline algae and vermatid gastropods. The coralline algae occur in forms of cups or funnels

algal ridge - a low ridge at the seaward margin of a reef flat, largely composed of skeletons of calcareous algae. A synonym of Lithothamnion ridge

algal turf - densely packed algae, usually filamentous, which rise less than one centimeter above the substratum upon which they are growing. A synonym of turf algae

alien species - a species which does not naturally occur within an area and which has usually arrived as a result of deliberate or accidental human intervention. Alien species often have adverse effects on native species as a result of competition

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allopatric species - species occupying mutually exclusive geographical areas

almost atoll - an atoll whose rim is less than 75 percent complete as a circle at low tide

anastomose - a term that refers to coral branches which grow back together after the initial division

animated GIF (Graphics Interchange Format) file - a graphic image on a Web page that moves

A marine segmented worm of the phylum Annelida.

Annual Composite HotSpot map - a map that composites all of the average monthly HotSpot (see HotSpot) images for a given year

anomaly - the deviation of a particular variable (e.g., temperature) from the mean or normal over a specified time

anthocaulus - a polyp that develops asexually on the skeletons of some coral species

Anthozoa -a class of Cnidaria that includes the stony corals, soft corals, sea anemones, gorgonians, and corallimorpharians

anthropogenic - made by people or resulting from human activities

aphotic zone - that portion of the ocean where light is insufficient for plants to carry on photosynthesis

Aplacophora - a class of Mollusca. They are a small group (less than 300 species) of wormlike mollusks that lack a shell. Some are associated with soft corals. Creeping species feed on cnidarians. Burrowing species are deposit feeders and carnivores

apron reef - the initial stage of a fringing reef. It is discontinuous and covers a small area

aragonite - a mineral species of calcium carbonate (CaCO₃) with a crystal structure different from the other two forms of CaCO₃—vaterite and calcite. It is precipitated from ocean surface waters mainly by organisms (e.g., coral) that use it to make their shells and skeletons

aragonite skeleton - skeletons primarily composed of the aragonite form of calcium carbonate

arborescent colony - a coral colony with a tree-like growth structure

A spiny lobster (phylum Arthropoda).

Arthropoda - an animal phylum that contains lobsters, crabs, shrimp, mantis shrimp, barnacles and copepods, fairy shrimp (all crustaceans), insects, centipedes, millipedes, spiders, scorpions, horseshoe crabs, pycnogonids (sea spiders), ticks and mites. Approximately three quarters of a million species are described, many more than all the other animal phyla combined. The crustaceans are the arthropods associated with coral reefs

artificial reef - an artificial structure placed on the ocean floor to provide a hard substrate for sea life to colonize. Artificial reefs are constructed by sinking dense materials, such as old ships and barges, concrete ballasted tire units, concrete and steel demolition debris and dredge rock on the sea floor within designated reef sites

artisanal fishing - fishing which is typically a small-scale operation that uses simple fishing methods; fishing for subsistence by coastal or ethnic island groups using traditional methods; fishing with the purpose of catching/collecting aquatic products for sale

asexual reproduction - reproduction that does not involve the union of sex cells (gametes) to produce a zygote. Examples in corals are budding and fragmentation

A small Pacific atoll. Note the coral reef encircling the calm and shallow lagoon.

auricularia - the primary larval stage in holothuroid (sea cucumber) development

autecology - the ecology of a single species

automated bleaching early warning system - automated bleaching alerts/warnings directly from satellite and/or in situ derived indices

autotomy - a means of asexual reproduction by the break up of a parent polyp

autotrophic - relating to organisms that have a type of nutrition in which organic compounds used in metabolism are obtained by synthesis from inorganic compounds

Artist's rendition of POES satellite.

axial corallite - a corallite which forms the tip of a branch

azooxanthellate coral - a coral which does not have symbiotic zooxanthellae in its tissues

Emergent coral heads in a back reef zone. (Photo: Great Barrier Reef Marine Park Authority)

bank - a broad elevation of the sea floor around which the water is relatively shallow but not a hazard to surface navigation

bank reef - large reef growths, generally having irregular shape, which develop over submerged highs of tectonic or other origin and are surrounded by deeper waters

bank/shelf - deepwater area extending offshore from the seaward edge of the fore reef to the beginning of the escarpment where the insular shelf drops off to the deep, oceanic water. If no reef crest is present, it is the flattened platform between the fore reef and the deep ocean waters or between the intertidal zone and open ocean

bar - an elongate submarine shoal

barren zone - the region of a coral reef seaward of the lower palmata zone and just landward of the buttress or mixed zone

barrier reef - a long, narrow coral reef, roughly parallel to the shore and separated from it by a lagoon of considerable depth and width. It may lie a great distance from a continental coast. It is often interrupted by passes or channels

basal plate - lower part of the coral cup, separating the polyp from the substratum. A synonym of pedal disc

bathymetry - the science of measuring ocean depths to determine the topography of the sea floor

Image of the commercially harvested “beche de mer”.

belt transect - a linear or circular transect with the observation area being a specified distance on either side of the transect line

benthic organism (benthos) - an organism whose habitat is on or near the bottom of a stream, lake, or ocean

A benthic crab (phylum Arthropoda).

bifacial - describes plates which have corallites on both sides

bifurcate - a coral branch that divides into two equal branches

binomen - a two-part name given to a species in which the first part is the name of the genus and the second is the specific name

binomial nomenclature - a system of nomenclature where each animal has a dual name consisting of genus and species, e.g., the boulder coral, Montastrea annularis

bioacoustics - a discipline of zoology that is concerned with sounds of biological origin: their mechanisms of production, physical properties, receptors and reception physiology, and the role of the sounds in behavior

biochore - a group of similar biotopes

biocoenose - an assemblage of diverse organisms inhabiting a common biotope

biocoenosis - a community or natural assemblage of organisms. The term often is used as an alternative to ecosystem, but strictly it is the fauna/flora association excluding physical aspects of the environment

A coral reef contains a great variety of species of all major kingdoms of living forms. (Photo: Dr. Anthony Picciolo)

biodiversity hot spot - an area that features exceptional concentrations of species, including many endemics. Many such hot spots also experience large habitat losses, putting these ecosystems at risk

bioerosion - erosion of the physical/geological environment by organism activities such as boring, scraping, etching, etc.

biogenic - resulting from the actions of living organisms

biogenic reef - a mound-like layered structure built by and predominantly composed of organic remains such as shells and skeletons of sedentary organisms

biogenic rock - an organic rock produced by the physiological activities of plants or animals

biogeochemical cycle - the chemical interactions among the atmosphere, biosphere, hydrosphere, and lithosphere

biogeography - a branch of biology that deals with the geographical distribution of organisms

bioherm - a body of rock built up by or composed mainly of sedentary organisms, e.g., hard corals, calcareous algae or mollusks, and enclosed or surrounded by rock of different origin

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biolimiting - relating to the environmental factors determining or restricting the growth of a particular life form

biological productivity - the amount of organic matter, carbon, or energy content that is accumulated during a given time period

A bioluminescent comb jelly of the phylum Ctenophora.

biomass - an estimate of the amount of living matter per some unit volume or area

biome - a community of animals and plants occupying a climatically uniform area on a continental scale

biosphere - the system of Earth and its atmosphere that supports life. The marine biosphere includes the biota and detritus in the oceans

biota - all life forms of a given area

biotope - an area of relatively uniform environmental conditions, occupied by a given plant community and its associated animal community

bioturbation - the rearrangement of sediments by organisms that burrow through them and ingest them

bitmap image - also called raster or paint images. They are made of individual dots called pixels (picture elements) that are arranged and colored differently to form a pattern. Compared to a vector image, bitmap images are great for photographs because they tend to offer greater subtleties for shading and texture but require more memory and take longer to print. Vector images are best for drawings that need sharper lines, more detail, and easy modification. Vector images require far less printing resources than bitmap images

A scallop (class Bivalvia) displays its rows of light-sensitive eyespots.

bleaching index - index based on the strength and duration of local HotSpots to monitor bleaching events

bleaching outbreaks - development of bleaching events

bleaching stressors - environment-induced stress that results in bleaching, e.g., disease, excessive or insufficient light, increased levels of ultraviolet radiation, sedimentation, pollution, salinity changes, and increased temperatures

bloom - a sudden increase in the biomass of phytoplankton or benthic algae in a given area

BOD (Biological (or Biochemical) Oxygen Demand) - the oxygen used in meeting the metabolic needs of aerobic microorganisms in water rich in organic matter (as water polluted by sewage)

boring sponge - a sponge that chemically digests the limestone skeletons of corals during its search for food and living space, which breaks down the structure of the reef

boss - a columnar, flat-topped coral-algal growth or erosion structure usually found on the upper surfaces of spurs and buttresses

bottlebrush branching - describes a branch with compact radial sub-branches

branching colony - a coral growth pattern where branches are formed

breaker zone - the area of a coral reef most exposed to breaking waves

broadcast spawner - an organism that releases gametes directly into the sea for external fertilization

brooder - a coral which harbors or broods developing larvae within its polyps

brooding - the development of larvae within the gastrovascular cavity of an adult coral polyp

Bryozoa - an animal phylum that contains approximately 5,000 living species. They are all sessile colonial forms composed of zooids. Zooids are tubular, oval or box-like structures that contain a lophophore, which is 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

budding - a form of asexual reproduction in corals where a parent corallite forms daughter corallites

buoy - a floating platform for navigational purposes or supporting scientific instruments that measure environmental conditions

buttress - see spur and groove

CaCO₃ (calcium carbonate) - a molecule consisting of calcium, carbon and oxygen secreted by corals to their skeleton. It is also secreted by mollusks to form their protective shells

calcareous - composed of or containing a substance made of calcium carbonate

calcification - the process by which corals and calcareous algae extract calcium from seawater and produce it as calcium carbonate

calcite - a mineral made up of a crystalline form of calcium carbonate

calcite skeleton - a skeleton composed of the calcite form of calcium carbonate

calyx (pl. calices) - the upper or open end of the corallite or coral polyp cup

carbohydrates - organic compounds composed of carbon, oxygen, and hydrogen; includes the simple sugars, double sugars, and complex sugars (starches)

carbon compensation depth - the level in the ocean below which the solution rate of calcium carbonate exceeds its deposition rate

carbon cycle - the cycling of carbon in the form of carbon dioxide, carbonates, organic compounds, etc., between various reservoirs, e.g., the atmosphere, the oceans, land and marine biota and, on geological time scales, sediments and rocks

CARICOMP (Caribbean Coastal Marine Productivity) - a regional coral reef, seagrass and mangrove monitoring program and network involving a number of Caribbean laboratories, parks and reserves to study land-sea interaction processes in the wider Caribbean region. Twenty-seven institutions in 17 countries participate in CARICOMP

A carnivore (barracuda) caught in the act.

carrying capacity - the maximum population size that can be regularly sustained by an environment; the point where the population size levels off in the logistic growth model

CASI (Compact Airborne Spectrographic Imager) - a digital airborne multispectral sensor

cation - a particle that carries a positive electrical charge. The cation gets this positive charge from losing negatively charged electrons

cell - the smallest unit of living matter. All organisms are composed of cells and cell products (Cell Theory). Organisms exist either as single cells (unicellular) or as multicellular units

cement - the chemically precipitated calcium carbonate present in spaces within skeletons or between grains of internal sediment

Cephalopoda - a class of the phylum Mollusca that includes squids, octopods, cuttlefishes and nautili. Many species are inhabitants of coral reefs

A pair of butterfly fishes (Chaetodontidae). Their presence and behavior serve as biological indicators of reef health.

chain transect - a linear transect where a chain is used to mark the line under study. By following the surface contour of the reef, chain transects provide data that may be used to calculate the estimated spatial index (the ratio of reef surface contour to linear distance of the reef)

CHAMP (Coral Health And Monitoring Program ) - a NOAA program whose mission is to provide services to help improve and sustain coral reef health throughout the world. Long term goals are: establish an international network of coral reef researchers for the purpose of sharing knowledge and information on coral health and monitoring; provide near real-time data products derived from satellite images and monitoring stations at coral reef areas; provide a data repository for historical data collected from coral reef areas; and add to the general fund of coral reef knowledge

chemosynthesis - the formation of organic compounds with energy derived from inorganic substances such as ammonia, sulfur and hydrogen

chemotrophs - organisms (usually bacteria) that derive energy from inorganic reactions; also known as chemosynthetic organisms

chlorophyll - a green pigment present in green plants and cyanobacteria. Chlorophyll is essential in the transformation of light energy to chemical energy in photosynthesis

chloroplast - a disk-like organelle with a double membrane, found in some protists and all green plant cells, that contains chlorophyll and is the site of photosynthesis

Chordata - an animal phylum that includes sea squirts (tunicates), lampreys and hagfishes, fishes, amphibians, reptiles, birds and mammals. Many species of marine chordates play prominent roles in the ecology of coral reef ecosystems

chronology - the age-depth relationship in ice, sediment, or another deposit. Ages are usually measured for discrete samples, and the ages of intermediate samples are interpolated between samples with measured ages

Ciguatera food poisoning may be contracted by eating the flesh of a contaminated barracuda.

cilia - microscopic motile hair-like structures growing on the ectodermis (outer body covering) of polyps or planulae which aid in locomotion and the movement of mucus

clade - a group of species with a common evolutionary ancestry

cladistics - the systematic classification of groups of organisms on the basis of the order of their assumed divergence from ancestral species

classification - a system of nested hierarchical categories used to efficiently store information about biological diversity

cleaning behavior - mutualistic behavior in which larger animals, usually fishes, permit smaller animals, usually other species of fishes or invertebrates, to clean them of external parasites

cleaning station - a site visited by fishes where, in a mutually symbiotic relationship, cleaning shrimp or fish remove parasites from their bodies

climate - long-term characteristics of weather

climate change - the long-term fluctuations in temperature, precipitation, wind, and all other aspects of the Earth's climate. It is also defined by the United Nations Convention on Climate Change as “change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods”

climate-induced bleaching - coral bleaching as a result of changing climate patterns, e.g., temperature

climate variability - changes (variability/trends) in the long-term characteristics of weather

climax - the final stage in ecological succession that is able to persist in the absence of environmental change

CLOD (Coralline Lethal Orange Disease) - a disease which infects coralline algae

clone - an individual genetically identical to the parent organism, created by the splitting off or budding of cells from the parent organism

cloning - the process of asexual reproduction in an otherwise multicellular organism

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cnida - an organelle located in cnidocytes that is capable of eversion

Cnidaria - a multicellular animal phylum, with a tissue grade of construction, that contains the stony (hard) corals, anemones, sea fans, sea pens, hydroids, and jellyfish

cnidocyte - a stinging cell of jellyfish, hydroids, sea anemones and corals. The cnidocyte contains the eversible cnida. The most common type of cnidocyte is the stinging structure known as the nematocyst. Nematocysts are located throughout the epidermis, but are especially abundant on the tentacles

coastal area - the areas of land and sea bordering the shoreline and extending seaward through the breaker zone. Coastal areas throughout the world are under enormous environmental stress, which is caused by a wide range of factors, including pollution and the destruction and deterioration of marine habitats

coastal reef - a coral reef occurring near and parallel to a coastline

coelenteron - the gastrovascular (digestive) cavity of a cnidarian or ctenophore

coelobite - an organism that lives in pores and spaces within a reef

coenenchyme - all of the tissue between the polyps of an anthozoan colony

coenosarc - the living tissue of a cnidarian polyp, consisting of the outer, nonciliated epidermis and the inner, ciliated gastrodermis with the thin, acellular meoglea in between. The coenosarc connects the coral polyps of a coral colony. It spreads along the surface of the calcareous exoskeleton

coenosteum - the common surface of corallum between calices

coenosteum pit - the point of insertion or commencement of septa in some corals

colonial coral - a coral composed of many individuals

colonized hardbottom - a substrate formed by the deposition of calcium carbonate by reef building and other organisms. Habitats within this category have some colonization by live coral

columella - the central structure of the calyx formed by fusion of the septa

columnar colony - a coral colony formed into one or more columns

commensal - having benefit for one member of a two-species association but neither positive nor negative effect on the other

compact branching - a growth pattern where the coral branches are close together

coral - a general term used to describe a group of cnidarians; indicates the presence of skeletal material that is embedded in the living tissue or encloses the animal altogether

coral assemblage - a group of corals

coral bleaching - the process in which a coral polyp, under environmental stress, expels its symbiotic zooxanthellae from its body. The affected coral colony appears whitened

Section of a graphic depicting areas of elevated ocean temperatures that may result in coral bleaching events.

coral growth line - a minute growth line on the outer surfaces of corals that have a calcified outer wall. The carbonate is produced by zooxanthellae which create a series of diurnal growth increments

coral reef - a wave-resistant structure resulting from cementation processes and the skeletal construction of hermatypic corals, calcareous algae, and other calcium carbonate-secreting organisms

Coral Bleaching HotSpot monitoring program - a NOAA program that uses satellite and in situ monitoring stations to monitor high sea surface temperature events and to analyze conditions that may lead to coral bleaching

coral reef bleaching monitoring product - near real-time information derived from data either from satellite images or in situ monitoring stations at coral reef areas to help improve and sustain coral reef health throughout the world

Coral Reef Watch - see CRW (Coral Reef Watch) Program

Coral Stress Index - an index that indicates the relative accumulated thermal stress experienced by a given coral reef

Corallimorpharia - an order of the subclass Zoantharia (Hexacorallia) of the phylum Cnidaria. They are mostly solitary species (some are colonial) that resemble true corals, but lack a calcareous skeleton

coralline algae - algae that form solid calcium carbonate accretions

corallite - a coral cup; the skeleton of an individual polyp

Parrotfish are often coralliverous, scraping the coral polyps with beaklike jaws.

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corallum - a complete coral colony; a coral head

CoRViL (Coral Reef Virtual Laboratory) - a joint venture of the National Oceanic and Atmospheric Administration (NOAA), the Great Barrier Reef Marine Park Authority (GBRMPA), and the Australian Institute of Marine Science (AIMS). This venture will provide an automated, cooperative exchange of electronic data, computer processing power and remote sensing tools for the purpose of monitoring the coral reef environment on the Great Barrier Reef. It is anticipated that this effort will eventually provide a model for monitoring physical processes at other sensitive coral reef areas throughout the world

corymbose - describes coral colonies with horizontal interlocking branches and short upright branches

cosmopolitan distribution - worldwide distribution within habitat limits

costa - the extension of the septa outside the calyx into the coenosteum

CREWS (Coral Reef Early Warning System) - in situ NOAA meteorological and oceanographic monitoring sites that collect data continuously which are transmitted hourly via satellite to a data archival site. An automated system (hardware and software) that monitors select oceanographic and meteorological parameters and produces specialized alerts when conditions may result in environmental stresses conducive of coral bleaching. NOAA plans to expand the CREWS from the Florida Keys/Bahamian sites to many remote coral reef sites throughout the world

critical depth - the depth at which phytoplankton photosynthesis for the water column is equal to phytoplankton respiration for the water column

A marine shrimp (Crustacea).

CRW (Coral Reef Watch) program - formed in 2000, NOAA’s CRW maximizes NESDIS’s coral reef resources by joining and building on existing NESDIS coral reef strengths under a more coordinated program. It seeks to develop a long-term coral reef monitoring system with the ability to predict coral bleaching episodes in all major U.S. coral reef areas

ctenophore - a member of the animal phylum Ctenophora. A small phylum (about 50 species) whose members, known as comb jellies and sea walnuts, superficially resemble jelly fishes. These planktonic organisms are thought to have evolved from a medusoid cnidarian

cyanide fishing - a destructive fishing technique in which sodium cyanide or some other cyanide compound is used to stun and capture coral reef fishes for the aquarium and live food trade

A bloom caused by cyanobacteria (“blue-green algae”).

cyclosystem - a system of very small tubules that links the polyps of calcareous colonial hydrozoans

cystid - the exoskeleton and body wall of the stationary trunk of bryozoans

CZCS (Coastal Zone Color Scanner) - a scanning radiometer with six spectral channels centered at 0.443, 0.520, 0.550, 0.670, 0.750 and 11.5 micrometers and selected to allow measurement of ocean color and temperature, suspended sediment and chlorophyll concentrations, and ocean pollutants

dactylozooid - a hydrozoan polyp that is specialized for food capture

1985-2000 average sea surface temperature from AVHRR Pathfinder.

decadal - refers to a climatic process that re-occurs every decade or once every few decades

decomposer - a heterotrophic organism that breaks down dead biological matter and uses some of the products and releases others for use by consumer organisms

decomposition - the breakdown of organic matter by bacteria and fungi

deep fore reef - the deepest seaward part of a coral reef; a vertical cliff beginning at a depth of about 60 m

Degree Heating Week (DHW) - the NOAA satellite-derived Degree Heating Week (DHW) is an experimental product designed to indicate the accumulated thermal stress that coral reefs experience. A DHW is equivalent to one week of sea surface temperature 1 deg C above the expected summertime maximum. For example, 2 DHWs indicate one week of 2 deg C above the expected summertime maximum

Degree Heating Week accumulation - accumulated thermal stress that coral reefs experience over a typical 12-week period

delta notation - the absolute abundance of an isotope is difficult to measure with accuracy. Therefore, we compare isotopic ratios in a sample with those in a standard resulting in the delta-notation: d(x) = [{Rx - Rst}/Rst] x 103, where d(x) is the delta-value of a sample, Rx and Rst are the isotopic ratios in sample (Rx) & standard (Rst). The d-value is the relative difference in the isotopic ratio of the sample and the standard. It is expressed in part per mille (o/oo); that is why the right-hand side of the equation is multiplied by 103 (1000). Carbon and oxygen data from carbonates are usually referred to the PDB standard (a belemnite, Belemnitella americana, from the Late Cretaceous PeeDee Formation in South Carolina)

deposit feeder - an animal that feeds on nutrients in the sediments

detritus - the particulate decomposition or disintegration products of plankton, including dead cells, cell fragments, fecal pellets, shells, and skeletons, and sometimes mineral particles in coastal waters

detrivore - an animal that eats detritus

diffusion - the movement of particles from an area of higher concentration to an area of lower concentration

dioecious - having separate sexes. Individuals within the species contain only one or the other of male and female reproductive systems

disease - any impairment of an organism's vital functions or systems, including interruption, cessation, proliferation, or other malfunction

DNA (deoxyribosenucleic acid) - also termed deoxyribonucleic acid. The molecule that encodes genetic information in the cells. It resembles a double helix held together by weak bonds of four nucleotides (adenine, guanine, cytosine, and thymine) that are repeated ad infinitum in various sequences. These sequences combine into genes that govern the production of proteins. The DNA located within the nuclear membrane of eukaryotic cells is sometimes referred to as nDNA

dot grid - a technique used to analyze a photograph of a quadrat (photo-quadrat), in which a grid of random dots is placed over an image of the photo-quadrat. It assumes that the proportion of dots that lies on a substrate is equal to the proportional area of the substrate

downwelling - a downward current of surface water in the ocean, usually caused by differences in the density of seawater

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A pencil urchin of the phylum Echinodermata.

echinopluteus - a larval form of some echinoderms

Echiura - an animal phylum that contains the echiurans or spoonworms. Some species inhabit coral crevices. Echiurans are deposit feeders

ecological isolation - a form of reproductive isolation in which two closely-related species are separated by what is often a slight difference in the niches they occupy

ecology - the study of the interrelationships between organisms and their environment, including the biotic and abiotic components

ecosystem - an ecological community considered together with the non-living factors of its environment as a unit

ectodermis - the outer cellular covering of a polyp

ecotone - a transitional area between two adjacent ecological communities

Graphic of sea surface temperatures show El Niño, May 1997.

encrusting colony - a thin colony which adheres closely and is attached to the substrate

endemic species - a species whose distribution is restricted to a particular area

endobenthic - refers to meiofaunal-sized organisms that move within the sediments

endolithic - growing within a rock or any other hard inorganic substratum

endosymbiotic - being symbiotic and living within the body of an individual of the associated species

endozooic - living inside an animal

energy flow - the movement of energy through a community via feeding webs

ENSO (El Niño Southern Oscillation) - see El Niño and Southern Oscillation

environment - everything external to the organism

environmental stress - severe environmental effects on the natural ecosystem

epibenthic (epifaunal or epifloral) - refers to organisms living on the surface of the substrate

epibiont - an organism that lives on the outside of another organism

Star coral shedding gametes in an epidemic spawning event

epidermis - the outer epithelial layer of the body

epifauna - animals that live upon or are associated with substratum features

epiphyte - microalgal organism living on a surface (e.g., on a seaweed frond); a plant living on the surface of another plant

epitheca - a layer of calcium carbonate that grows outside corallite walls

epizoite - an animal that lives on the surface of another organism

eukaryotic - descriptive of organisms with cells having a distinct nucleus with nDNA, and intracellular membranes. This includes all protists, fungi, plants and animals. The organisms are termed eucaryotes

euphotic zone - the layer of the ocean that receives sufficient sunlight for photosynthesis. The depth to which 1% of incident light penetrates (1% is the minimum amount of light required for photosynthesis)

eutrophic - a situation in which the increased availability of nutrients such as nitrate and phosphate stimulates the growth of plants such that the oxygen content is depleted and carbon sequestered

Executive Order 13089 - on June 11, 1998, President Clinton issued Executive Order 13089 directing all agencies to increase their efforts to protect our nation’s coral reef resources. The executive order calls for the establishment of a U.S. Coral Reef Task Force, cochaired by the Secretaries of the Interior and of Commerce. The Task Force will develop and implement a comprehensive program of inventory, monitoring, and research to map and identify the major causes and consequences of degradation of coral reef ecosystems

Executive Order 13158 - on May 26, 2000, President Clinton signed Executive Order 13158 on Marine Protected Areas (MPAs) to strengthen the protection of U.S. ocean and coastal resources. This significant milestone in ocean conservation directs the Departments of Commerce and the Interior, and other federal agencies, to strengthen and expand a national system of MPAs by working closely with state, territorial, local, tribal, and other stakeholders

extant species - species which are now living

extinct species - species for which there are no living representatives

extinction coefficient - a coefficient measuring the rate of extinction, or diminution, with distance of transmitted light in sea water

extratentacular budding - an asexual form of reproduction where daughter corallites grow from the outside wall of the parent corallites

The rounded upper surface of this jellyfish is the exumbrella.

faro - a rhomboid-shaped, steep-sided, continental shelf atoll

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

fish census - the collection of data over time concerning the species of fishes in an area, their relative abundances, and population densities

fissure - a deep and narrow depression cutting across the reef front with origins relating to jointing planes in the reef limestone or non-limestone bedrock

flaring corallite - a corallite with expanding, trumpet-like curves to the outer corallite wall

fluorescence - the emission of light from a substance caused by exposure to radiation from an external source

foliose coral - a coral whose skeletal form approximates that of a broad, flattened plate

fore reef - the portion of a reef seaward of reef crest. A synonym of reef slope

fore reef escarpment -a slope or cliff seaward of the fore reef terrace, at a depth of about 25-30m

fore reef slope - a sand covered, gradual or sharply descending slope; the next-to-deepest part of the fore reef

fore reef terrace - the uppermost portion of the fore reef; a flat plain beginning at the base of the buttress or mixed zone, at a depth of about 60 m

fossa - a hole or cavity in the coral skeleton

foveolate corallite - a corallite of some species which is located at the base of a funnel-shaped depression

fragmentation - a type of asexual reproduction common in branching corals. Branches break off from the parental colony to establish other colonies nearby

framework - a rigid, wave resistant calcareous structure constructed by sessile organisms such as sponges, corals, and bryozoans, in a high energy environment

free-living coral - a coral which is not attached to a substrate

A fringing reef off a South Pacific Island.

gamete - a sex cell, e.g., a spermatozoan or egg cell, produced by sexually reproducing orgnaisms

gap analysis - a Geographic Information System (GIS) methodology to identify the distribution of biodiversity over large spatial areas. It was developed in 1988 by the U.S. Geological Survey in an effort to ensure that regions rich in species diversity are conserved with the hope that this will eliminate the need to list species as threatened or endangered in the future. The gap analysis approach uses maps of vegetation and predicted animal distributions to locate centers of species richness outside areas currently managed for biodiversity protection. These are considered the "gaps" of gap analysis. Thus far, its use primarily has been in the terrestrial sphere

gas chromatography - the separation of a mixture of compounds (solutes) into separate components, which then can be analyzed by a mass spectrometer to yield detailed empirical molecular information regarding the chemistry of the samples

gastrodermis - the epithelial lining of the gastrovascular (digestive) cavity of cnidarians and ctenophores (comb jellies)

A sea slug of the Class Gastropoda, Phylum Mollusca.

gastrovascular cavity - the internal digestive cavity of cnidarians and ctenophores that is lined with the gastrodermis

gastrozooid - a polyp in hydrozoans and other cnidarians which is specialized for feeding

GCRMN (Global Coral Reef Monitoring Network) - a global network whose aim is to improve management and sustainable conservation of coral reefs for people by assessing the status and trends in the reefs and how people use and value the resources. It does this by providing many people with the capacity to assess their own resources, within a global network, and to spread the word on reef status and trends

geochemistry - the study of the chemical elements, their isotopes, and related processes with respect to the abundance and distribution of materials within the Earth’s waters, crust, and atmosphere

geographical isolation - a form of reproductive isolation in which members of a population become separated from another population by geographical barriers that prevent the interchange of genes between the separated populations

geologic time scale - a relative time scale based upon fossil content. Geological time is divided into eons, eras, periods, and epochs

Artist’s rendition of GOES I/M, geostationary satellites whose mission includes data collection and broadcasting, and environmental sensing. (Image: NASA/Goddard Space Flight Center)

GIF (Graphics Interchange Format) - a bit-mapped digital image graphics file format suitable for efficiently importing image data into computer files or for transmitting or displaying the formatted image on a computer monitor or printing it out. GIF supports color and various resolutions. It also includes data compression, making it especially effective for scanned photos

GIS (Geographic Information System) - a system that allows automatic location of information suitable for mapping. Usually involves a software system that takes geographic position data and other data (e.g., type of bottom sediment) in order to create a map. Data on processes (e.g., current speed) can be incorporated to make a geographic model of flow

global change - a transformation which occurs on a worldwide scale (for example, an increase in CO2 in the atmosphere) or exhibits sufficient cumulative effects to have worldwide impact (for example, local species extinction resulting in global loss of biodiversity)

global warming - an increase in temperature that occurs globally

GOES (Geostationary Operational Environmental Satellite) - a class of satellite operated by NOAA, positioned in a nearly stationary orbit over the equator at an altitude of about 22,500 miles. GOES-8 is currently the operational “east” spacecraft at 75 degrees West longitude, while GOES-10 is the “west” spacecraft located at 135 degrees West. GOES-11 is in standby at 110 degrees West

gonads - the primary sex organs of an animal. In males they are the testes, and in females, the ovaries

gonochoric - having separate sexes. Individuals within the species contain only one or the other of male and female reproductive systems

A sea fan, Gorgonia ventalina, in the Florida Keys.

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GPS (Global Positioning System) - a network of 24 radio transmitting satellites (NAVSTAR) that provide accurate geographical position fixing

greenhouse effect - the heating that occurs when gases such as carbon dioxide trap heat escaping from the Earth and radiate it back to the surface

greenhouse gases - atmospheric gases, primarily carbon dioxide, methane, and nitrous oxide restricting some heat-energy from escaping directly back into space

gross primary production - the total amount or weight of organic matter created by photosynthesis over a defined time period (total product of photosynthesis)

growth band – a band formed yearly on coral by the secretion of CaCO₃; one yearly growth band contains two smaller bands representing winter growth and summer growth

guyot - a flat-topped submarine mountain

habitat- the place or environment where a particular organism, population, or species lives

half-life - the time required for a radioactive substance to lose half of its nuclei

Halimeda - an important genus of calcareous green algae in coral reef environments

A black mangrove is an example of a halophyte, a plant that thrives in a saline environment.

hard bottom - a substrate formed by the deposition of calcium carbonate by reef building corals and other organisms or existing as bedrock or volcanic rock usually of minimal relief

hard coral - a coral in the anthozoan order Scleractinia. Also known as the stony corals, these organisms possess a hard external calcareous skeleton. A synonym of stony coral

hard coral forms - may be conveniently summarized as: encrusting (lichen-like); branched (staghorn-like); massive (rock-like); sub-massive (pillar-like); tabulate (table-like); foliose (scroll-like); and solitary

herbivore -an animal that feeds on plants

hermaphrodite - an animal or plant which is equipped with both male and female reproductive organs

hermatypic coral - a reef-building coral with zooxanthellae in its tissues

heterotroph - an organism that cannot manufacture its own food, and therefore requires external sources of energy

hexamerous - having six parts, or parts in multiples of six arranged radially, as found in anthozoans in which the tentacles and mesenteries are in multiples of six

high-resolution satellite SST climatology - 9 km monthly or yearly averages of satellite-derived (See AVHRR) sea surface temperatures obtained over periods of 10 years or longer

hoa - a channel or pass connecting the atoll lagoon with the open ocean

holdfast - an organ used for attachment to a substrate

Holocene epoch - an epoch of the Quaternary period dating from the end of the Pleistocene approximately 8,000 years ago until the present

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holothurian - a sea cucumber in the echinoderm class Holothuroidea

holothurin - a toxic substance released by some holothuroids (sea cucumbers)

homeostasis - the ability to maintain a relatively constant internal environment

HotSpot animation - animations from HotSpot imagery denoting coral reef bleaching events over time

HotSpot charts - charted regions that highlight sea surface temperature (SST) anomalies that are greater than 1° C above the maximum monthly climatological SST. See also coral bleaching and coral bleaching hotspot

White-tipped mustard-colored fire coral in the Flower Garden Banks.

hybrid - an individual with parents of different species

Hyperspectral AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) - a hyperspectral image is a very high resolution image which was acquired with a hyperspectral scanner. These instruments acquire data in 224 contiguous channels of approximately 10nm bandwidth. They are spanning the visible, near-infrared and mid-infrared portion of the electromagnetic spectrum

ICRI (International Coral Reef Initiative) - an environmental partnership and network that brings all the stakeholders together with the objective of sustainable use and conservation of coral reefs for future generations. ICRI is an informal mechanism that allows representatives of over 80 developing countries with coral reefs to sit in equal partnership with major donor countries and development banks, international environmental and development agencies, scientific associations, the private sector and non-governmental organizations (NGOs) to decide on the best strategies to conserve the world's coral reef resources

IKONOS satellite - high-resolution (1-2 meter resolution) imaging satellite; the world’s first commercial satellite for imagery of this type

immersed corallite - a corallite that is embedded in the surrounding coenosteum

infauna - animals that inhabit the sandy or muddy surface layers of the ocean bottom, i.e., those that live buried or dig into the substrate

in situ - in the natural or original position

in situ data - measurements made at the actual location of the object or material measured, in contrast to remote sensing

insolation - the amount of solar radiation received on a given body or in a given area

interannual - refers to a climatic process that re-occurs every three to ten years. El Niño is an example of a climatic process that re-occurs every 4-6 years

interstitial fauna -animals that live in the spaces within sediment particles (interstitial spaces)

intertidal zone - the region between the highest water line and the mean low tide level

intratentacular budding - a type of asexual reproduction where daughter corallites grow from the inside wall of parent corallites, usually by division of the parent corallite

invertebrate - an animal that lacks a vertebral column (backbone)

ion - a positively or negatively charged atom produced through loss or gain of one or more electrons

IR (infrared) radiation - earth-emitted radiation over thermal wavelengths: 3-15 micrometers. Used for satellite remote sensing because it can be used to monitor weather and oceanographic conditions 24 hours a day

isotope - one of two or more species of atoms of the same chemical element that have the same atomic number and occupy the same position in the periodic table. They are nearly identical in chemical behavior, but they differ in atomic mass or mass number. Therefore, they behave differently in the mass spectrograph, in radioactive transformations, and in physical properties, and may be separated or detected by means of these differences

ITCZ (Intertropical Convergence Zone) - the region near the equator where the trade winds of the Northern and Southern Hemispheres converge

ITIS (Integrated Taxonomic Information System) - a partnership of U.S., Canadian, and Mexican agencies, other organizations, and taxonomic specialists cooperating on the development of an online, scientifically credible, list of biological names. ITIS is also a participating member of Species 2000, an international project indexing the world's known species

JPEG (Joint Photographic Experts Group) - the original name of the committee that wrote the standard. It is a lossy compression technique for color images. Although it can reduce files sizes to about 5% of their normal size, some detail is lost in the compression

A number of small keys (cays) in Jobos Bay, Puerto Rico.

keystone species - a species that is disproportionately important in the maintenance and balance of its community integrity

kingdom - a major division of living organisms. All organisms are classified into one of five kingdoms: Monera (the prokarytic Kingdom. Includes archaebacteria, eubacteria and cyanobacteria ); Protista (unicellular eukaryotes); Fungi (yeasts and mushrooms); Plantae (plants); and Animalia (animals)

knob - a projecting structure on the reef margin or reef front wherein the upper surface flares outward, giving the surface a greater diameter then the basal section

knoll - a small reef within the lagoon or on shallow shelves

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References

Academic Press Dictionary of Science and Technology. Accessed January 2002. Harcourt, Inc.
http://www.harcourt.com/dictionary/

Barnes, R.D. and E.E. Rupert. 1994. Invertebrate Zoology; Sixth Edition. Fort Worth, TX: Harcourt Brace College Publishers.

Baum, S.K. 1997. January 20, 1997. Glossary of Oceanography and the Related Geosciences with References. College Station, TX: Texas Center for Climate Studies, Texas A&M University.
http://stommel.tamu.edu/~baum/paleo/paleogloss/
paleogloss.html

Biological Chemistry Glossary. Accessed January 2002. Houston, TX: The University of Texas, Health Science Center at Houston.
http://www.uth.tmc.edu/uth_orgs/educ_dev/fellowship/
GOKA/BCGlos.HTM

Farabee, M.J. 2001. Online Biology Book. Avondale, AZ: Estrella Mountain Community College.
http://gened.emc.maricopa.edu/bio/bio181/BIOBK/
BioBookgloss.html

Global Change Glossary. Accessed January 2002. Oakland, CA: Pacific Institute for Studies in Development, Environment, and Security.
http://www.globalchange.org/glossall/gloindex.htm

Green, E.P., P.J. Mumby, A.J. Edwards, and C.D. Clark. 2000. Remote Sensing Handbook for Tropical Coastal Management. Edited by Alasdair J. Edwards. ISBN 92-3-103736-6, United Nations Educational, Scientific, and Cultural Organization (UNESCO).
http://www.unesco.org/csi/pub/source/rs.htm

International Center for Living Aquatic Resources (ICLARM) - World Fish Center. June, 1997. Reefbase 2.0.
http://www.reefbase.org/

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.

Kew, N., W. Bakker, and G. Denkinson. March 1996. The Satellite Imagery FAQ. European Space Agency/European Space Research Institute (ESA/ESRI).
http://atlas.esrin.esa.it:8000/lib/satfaq.html

Levinton, J. Glossary of Marine Biology. Accessed January 2002. From: Marine Biology: Function, Biodiversity, Ecology. New York: Oxford University Press.
http://life.bio.sunysb.edu/marinebio/glossary.html

N.J. McCormick and C.D. Mobley. Accessed January 2002. Optical Oceanography Glossary. Seattle, WA: Univ. of Washington.
http://www.me.washington.edu/faculty/McCormick/
glossary.htm

NOAA/NODC. 2001. Coral Reefs and Adjacent Ecosystems Website. Silver Spring, MD: NOAA
http://www.nodc.noaa.gov/col/projects/coral/
Coralhome.html

Senese. F., 2001. General chemistry Glossary. Frostburg, MD: Frostburg State Univ.
http://antoine.fsu.umd.edu/chem/senese/101/
glossary.shtml

Vernon, J. and M. Stafford-Smith, 2000. Corals of the World. Townsville, Queensland: Australian Institute of Marine Science.


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