Glossary of Terms

A mound like or flat-topped organic reef, generally less than 1 km across, frequently forming part of a larger reef complex.

Beach material usually well-rounded and between about 4mm to 64mm diameter.

A groyne with openings or voids large enough to permit passage of appreciable quantities of littoral drift through the structure.

The zone extending downward from the ocean surface within which the light is sufficient to sustain photosynthesis. The depth of this layer varies with water clarity, time of year and cloud clover, but is about 100m in the open ocean.

• It may be considered the depth to which all light is filtered out except for about one percent and may be calculated as about two and a half-times the depth of a secchi disk reading.

The science of deducing the physical dimensions of objects from measurements on images (usually photographs) of the objects.

An assemblage of photographs, each of which shows part of a region, put together in such a way that each point in the region appears once and only once in the assemblage, and scale variation is minimised.

A structure, ususally of open construction, extending out into the water from the shore, to serve as a landing place, recreational facility, etc., rather than to afford coastal protection or affect the movement of water. A term sometimes improperly applied to jetties.

A long, heavy timber or section of concrete or metal that is driven or jetted into the earth or seabed to serve as a support or protection.

For a plunging wave, the point at which the wave curls over and falls.

• The final breaking point of the waves just before they rush up on the beach.

A beach, usually small, in a coastal reentrant or between two littoral barriers (often rocky headlands).

The principle adopted by the OECD countries in 1972, requires that the polluter should bear the costs that pollution damage or pollution control impose upon society.

The introduction by man, directly or indirectly, of substances or energy into the marine environment (including estuaries) resulting in such deleterious effects as harm to living resources, hazards to human health, hindrance to maritime activities including fishing, impairment of quality for use of sea water and reduction of amenities.

• The contamination of the environment or poisonous substances.

A diverse group of chemicals that persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effects to human health and the environment. A group of twelve POPs (the "dirty dozen") have been initially selected for international action by the International Programme on Chemical Safety (IPCS).

A place where vessels may discharge or receive cargo; it may be the entire harbour including its approaches and anchorages, or only the commercial part of a harbour where the quays, wharves, facilities for transfer of cargo, docks, and repair shops are situated. Protection may be provided by natural or artificial features.

The essence of the approach is expressed in Principle 15 of the Rio Declaration that states "Where there are threats of serious or irreversible damage, lack of scientific certainty shall not be used as a reason to postponing cost-effective measures to prevent environmental degradation." The approach is concerned with avoiding risk that has not been assessed, i.e. uncertainty.

The process in which organisms synthesize organic matter from inorganic materials, or the organic matter itself.

The intersection of the ground surface with a vertical plane; typically perpendicular to the local shoreline, and may extend from behind the dune line or the top of a bluff to well seaward of the breaker zone.

The transmission of waves through water.