Glossary - A

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AbMAC
Abalone Mangement Advisory Committee

Abrolhos Islands
The Houtman Abrolhos Islands. An archipelago of islands lying 65-90 kilometres off Geraldton, on the coast of Western Australia.

Abundance
Number of fish in a stock or population.

Abundant
Plentiful, more than enough.

Abyssal plain
A large area of flat or gently sloping sea floor in the deepest parts of oceans.

ACCC
Australian Competition & Consumer Commission

Accidental
Happening by chance or unexpectedly or unintentionally.

Accretion (deposition)
The gradual extension of land by natural forces, as in the addition of sand to a beach by ocean currents.

Acid
A substance that yields a relatively high concentration of hydrogen ions when dissolved in water and has a pH less than 7.

Acid Sulphate Soils (ASS)
Soils containing iron sulfides, that when exposed to air after being disturbed, produce sulfuric acid and often release toxic quantities of iron, aluminium and heavy metals.

Acoustic tag
A sound-emitting device that allows the detection and/or remote tracking of fish in three dimensions.

ACWA
Aquaculture Council of WA

Adaptation
Evolutionary process whereby a population becomes better suited to its habitat or changing environment

ADC
Aquaculture Development Council

Adductor muscle
Muscle, which holds together the shells of molluscs or shellfish.

ADF
Aquaculture Development Fund

Adult (fish)
Mature fish capable of breeding.

Aerate
To charge water with oxygen.

Aerobic
In the presence of oxygen.

AFMA
Australian Fisheries Management Authority

AFZ
See Australian Fishing Zone

Age structure
The number of fish of different ages within a population.

Aggregation (fish)
The behavioural grouping of animals in a high concentration for reasons such as the concentration of food organisms or spawning.

AIMAC
Abrolhos Islands Management Advisory Committee

AIMDT
Australian Indonesia Maritime Delimitation Treaty

AIMS
Australian Institute of Marine Science

ALC
Automatic Location Communicator

Algae
Aquatic plant-like organisms.

Algal bloom
Rapid and excessive growth of algae, generally caused by high nutrient levels and favourable conditions.

Alkaline
A substance that yields a relatively high concentration of hydroxide ions when dissolved in water to raise the pH value above 7.0.

Alkalinity
The capacity of water for neutralizing an acid solution.

Alligator
Two species of large reptiles belonging to the order Crocodilia. They differ from crocodiles in having a broader, shorter snout.

Ammonia
Dissolved toxin released by metabolism. Produced by fish and is harmful if levels allowed to build up especially in aquariums.

AMSA
Australian Marine Science Association

Anaerobic
In the absence of oxygen.

Anal fin
The last ventral fin of fishes.

Anatomy
Shape, form and structure of plants and animals.

ANCA
Australian Nature Conservation Authority

Angling
The art of fishing with a rod.

Annelid
Invertebrates that display an elongate body with distinct segmentation and a digestive tract that lies in the coelom.

Anoxic
Oxygen absent, or too low to support life

Antenna (Antennae)
A sensory organ found in pairs on the heads of insects and crustaceans.

Antennules
in crustaceans, the first pair of feelers, usually sensory in function.

Anterior
the region of the body that is related to the front or head end of an organism.

Anti-fouling
the process of removing the accumulation, or preventing the accumulation, of micro-organisms, plants, algae and animals on submerged structures, especially ships’ hulls.

ANZFA
Australia, New Zealand Food Authority

Apex predator
animal that sits at the top of a food chain, usually with no natural predators once it had reached its adult stage.

Aphotic zone
the region below the photic zone, where light is absent.

Appendage
a functional projection from a animal surface.

AQIS
Australian Quarantine Inspection Service

Aquaculture
Commonly termed ‘fish farming’ but broadly the commercial growing, holding or breeding of marine (mariculture) or freshwater animals and aquatic plants.

Aquatic
Organism living or growing in or near water

Archipelago
An ocean or sea with many islands.

Area closure
The closure of a fishing ground, or part thereof, used as a tool in the management of a fishery.

Area swept
In reference to a demersal trawl, it is the area of the sea floor over which the net is dragged during its operation, and is estimated by multiplying the width of the net mouth by the distance the net is dragged.  From data on the densities of fish caught in a unit area swept, an estimate of the biomass in that area can be obtained.

Artemia
A genus of crustacea found in salt lakes. Brine shrimp.

Arthropod
Invertebrate with jointed appendages and a chitinous, segmented exoskeleton.

Ascidacea
Tunicates with a typically sac-like, attached body as adults.

Asexual reproduction
A type of reproduction that employs means such as budding or binary fission, rather than the union of an egg and sperm.

Assemblage
Recognisable grouping or collection of individuals or organisms.

Assumption
Taken for granted or accepted as true without proof.

Australian Exclusive Economic Zone
Australia’s exclusive economic zone extends from the outer edge of the territorial sea up to 200 nautical miles from the territorial sea baseline.

Australian Fishing Zone (AFZ)
200 nautical mile (nm) wide zone around the Australian coastline withing which control over domestic and foreign access to resources is maintained.

Autotroph
An organism that can capture energy to manufacture its own food from raw materials.

Axis (Earth’s)
The imaginary line going through the north and south poles around which the earth spins.