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Government of Western Australia - Department of Fisheries

Glossary - D

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Department of Agriculture, Fisheries and Forestry (Commonwealth)

Development and Better Interest Fund

Remains of anything broken down.

Has 10 legs.

Organisms that break down dead organic matter into chemical nutrients.

Decompression Sickness
Suffered by deep sea divers. Changes in water pressure cause nitrogen bubbles to form in the blood stream. Also known as ‘the bends’.

Formerly the Department of Environment and Heritage (Commonwealth).  Now Department  of Sustainability, Environment, Water, Population and Communities.

Intentional; not accidental.

Bottom-dwelling, or living near the ocean floor.

Demersal trawling
Operation of a trawl net designed for use on or near the bottom of the sea or lake.

The mass per unit volume of a substance.

Small tooth or tooth-like structures.

Removal of oxygen from water.

Dependent variable
A factor whose value changes when the independent variable is changed.

Depletion (stock depletion)
Reducing the abundance of members of a fish stock through fishing.

The removal of salts from saline water to provide freshwater.

The dehydration of an organism.

An organism that feeds on dead and decaying organic matter.

Dead and decaying organic matter.

Development (of fisheries)
Transition from exploratory and experimental fishing, to the establishment of commercial activities and markets, with the ultimate goal of sustained long-term fishing.

Microscopic algae with cell walls made of silicon.

Divided or dividing into two parts or classifications.

What a person or animal usually eats and drinks.

A licensed fishing boat less than 6.5 metres, usually attached to a lead or mother boat in a fishing unit.

Microorganisms with both plant-like and animal-like characteristics, usually classified as protozoans having two lash-like structures (flagella) used for locomotion.

Having male and female reproductive organs in separate plants or animals.

Catch that is returned to the water, either dead or alive.

Disphotic zone
The lower depths of the photic zone below the euphotic zone.

To go or cause to go into solution.

Geographic area within which a species is generally found.

Diurnal tides
One high and one low tide is experienced each day.

Deoxyribonucleic acid, a molecule located in the nucleus of a cell that carries the genetic information that is responsible for running that cell.

To tame from a wild state through a process of selection.

Alive but not actively growing.

The upper side of an animal.   

Dorsal fin
Fin located on the upper side of fishes and some other vertebrate animals, used for stabilisation and manoeuvrability.                   

The common name for a dinghy when it is used in conjunction with a mother boat for troll lining when targeting Spanish mackerel.

A gillnet suspended by floats so that it fishes the top few metres of the water column.  Also called a pelagic gillnet.

An unattached fishing line with one or more hooks, held vertically in the water column with weights and marked with a buoy.  Generally used on the continental shelf and slope.  Several droplines may by operated by a vessel, using either manually or mechanically operated vessels.

Drum line
Method of fishing utliising a large hook, which may or may not be baited, attached by a heavy chain to a large floating drum, or buoy, which is anchored to the sea floor.


Last modified: 11/09/2012 11:11 AM

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