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Government of Western Australia - Department of Fisheries

Glossary - M

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MAC
Management Advisory Committee

Macroalga (macroalgae pl.)
Large alga that grows attached to the seabed (commonly known as a seaweed).

Magma
Hot fluid or semi-fluid material below or within the earth's crust from which lava and other igneous rock is formed by cooling.

Mammal
Any vertebrate of the class Mammalia, having the body more or less covered with hair, nourishing the young with milk from the mammary glands, and (with the exception of the egg-laying monotremes) giving birth to live young.

Managed fishery
A fishery declared by a management plan to be a managed fishery where a certain number of licences are issued and access to fishing grounds is limited.

Management plan
The rules and regulations governing a managed or interim managed fishery.

Mangrove
Salt-tolerant tropical evergreen tree or shrub of the genus Rhizophora that grows along tidal shores in estuaries and along coasts.

Man-made
Produced, formed or made by humans.

Mantle
Outgrowth of the body wall that lines the inner surface of the valves of the shell.

Mantle (Earth)
A highly viscous layer between the crust and the outer core. Earth's mantle is a rocky shell about 2,890 km (1,800 mi) thick that constitutes about 84 percent of Earth's volume. It is predominantly solid and encloses the iron-rich hot core, which occupies about 15 percent of Earth's volume.

Mariculture
Fish farming or aquaculture of marine animals or plants.

Marina
A boat basin offering dockage and other service for small craft.

Marine
Pertaining to the sea, from the open oceans to high water mark and into estuaries.

Marine Conservation Areas
Include marine nature reserves, marine management areas, marine parks and fish habitat protection areas, so some restrictions may apply to the collection of marine life.

Marine debris
Any persistent, manufactured or processed solid material discarded, disposed of or abandoned in the marine and coastal environment.

Marine Park
Created to protect natural features and aesthetic values while allowing recreational and commercial uses that do not compromise conservation values. Marine parks have three management zone options: sanctuary, general use and special purpose. 

MARPOL
International convention for the prevention of pollution from ships.

Maturity
Stage at which an animal can reproduce or breed.

Maximum sustainable yield
The maximum catch that can be removed over an indefinite period without causing the stock to the depleted, assuming that removals and natural mortality are balanced by stable recruitment and growth.

Meat weight
Animals are removed from shell from weighing such as abalone.

Medusae
The bell-shaped, free swimming stage of Cnidarians.

Meiosis
Cell division process that allows organisms to reproduce sexually producing gametes.

Megalopae
Post-larval stage in crustaceans.

Meroplankton
Organisms that are planktonic for only a part of their life cycle, usually during the larval stage.

Mesopelagic
The zone directly below the epipelagic where there is still faint light but not enough for photosynthesis (approximately 200 m – 1000 m). 

Metamorphosis
Rapid change of body shape such as the change from a larval form to an adult form.

Metaphor
States that an object is another or substitutes one object for another. E.g. All the world is a stage.

MFL
Managed Fishery Licence

Microalgae
Microscopic algae, typically found in freshwater and marine systems.

Microscopic
Organisms that cannot be seen with the naked eye.

Microorganism
Microscopic animal or plant.

Mid-ocean ridge
An underwater mountain system that consists of various mountain ranges (chains), typically having a valley known as a rift running along its spine, formed by plate tectonics.

Midden
A place where there is an accumulation of shell refuse that is derived from exploitation of a mollusc resource by Aboriginal people. Such sites may also contain artefacts, fireplaces, burnt shell and bones.

Migration
The systematic (as opposed to random) movement of individuals of a stock from one place to another.

Migration
To move from one habitat to another, usually for purposes of breeding or spawning.

Milligram (mg)
One-thousandth of a gram (g).

Milt
A fluid produced by male fish that contains sperm and is deposited over eggs released or laid by the female.

Mimicry
The resemblance of one organism to another or to an object in its surroundings for concealment and protection from predators.

Minimum legal size
Legislated size below which individuals of some fish species are not to be taken from the water and kept.

Minor fishery
One which is not currently cost recovered.  Once a Minor Fishery becomes subject to cost recovery, it ceases to be a Minor Fishery.

Mollusc
Any invertebrate (of the phylum Mollusca), usually contained within a hard shell, but can be without, such as abalone, oyster, mussels, snails, squid and octopus.

Monandric
Sex change occurs after female sexual maturity is reached.

Monera
Prokaryotic organisms – bacteria and cyanobacteria (blue-green algae)

Mortality
Frequency of death.

Mortality rate
Number of deaths per unit of population during a specified period.

Mitosis
Cell division process that allows organisms to reproduce asexually producing identical copies of the “parent” cell.

MOU
Memorandum of Understanding

Moult
To shed or discard old shell in order to grow a new one.

Mouth
The point where an estuary or river empties into another waterbody such as the ocean or lake.

MPG
Ministerial Policy Guideline

MSC
Marine Stewardship Council

MSY
See Maximum Sustainable Yield

Multicellular
An organism that consists of multiple cells.

 

Last modified: 16/08/2013 10:55 AM

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