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Government of Western Australia - Department of Fisheries

Glossary - S

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Freedom from risk, danger or injury.

Composed of salt; of the nature of salt.

The amount of salt dissolved in water. The average salinity of seawater is about 35 parts per thousand, or 3.5 per cent.

Ionic compounds composed of positively charged ions and negative ions so that the product is electrically neutral.

The movement of hard particles over an uneven surface in a turbulent flow of air or water.

Consisting of water containing salts.

Salt wedge
When less dense freshwater flows out of the estuary over a wedge of denser salt water entering from the ocean.

A portion, piece or segment that is representative of a whole.

Sanctuary Zone
Located within marine parks, sanctuary zones are “look but don’t take zones”, where surface water sports, snorkelling and SCUBA diving are permitted.

State Administrative Tribunal

Satellite tags
Collect horizontal and vertical movement and environmental data, pop off the organism at a pre-determined time, and transmit data to a satellite.

Southern Bluefin Tuna

Fish that have scales, unlike sharks and rays that have skin instead of scales.

An organism that feeds through chance encounters upon dead or decomposing organic matter.

Behavioural grouping together of fish, which then usually move together as a group.

Behavioural grouping together of fish, which then usually move together as a group.

Seas (waves)
An area that is part of an ocean, or is partially or fully enclosed, e.g., Timor Sea.

Sea cages
Cages suspended in the sea and used for aquaculture.

Sea surface salinity (SSS)
A common measure of ocean salinity is the concentration of dissolved salts in the upper layer of the ocean surface.

Seafloor spreading
A process that occurs at mid-ocean ridges where new oceanic crust is formed through volcanic activity and then gradually moves from the ridge.

Submerged marine flowering plants belonging to one of four plant families (Posidoniaceae, Zosteraceae, Hydrocharitaceae, or Cymodoceaceae).

An underwater mountain rising from the ocean floor and having a peaked or flat-topped summit below the surface of the sea.

Seas (waves)
Short wavelength waves generated by winds blowing at the time in the local area.

Seasonal closure
Closure to fishing at certain times (e.g for a period of weeks or months).

Seasonal restrictions
closure of fisheries to allow successful breeding an rejuvenation of fish stocks.

Red, green or brown marine algae.

A vessel or equipment able to meet the usual sea conditions.

Sea wrack
An assortment of seagrasses, algae, shells and the remains of animals such as sponges and sea urchins.

Secchi disc
A circular disc used to measure turbidity and transparency in bodies of water.

Secondary consumers
An animal that gets its energy from primary consumers.

Non-migratory, or tending to stay in one location.

Matter that falls to and lies at the bottom of the ocean.

Sediment transport
The movement of solid particles (sediment), due to a combination of the force of gravity acting on the sediment, and /or the movement of the water in which the sediment is located.

Performed in the pearling industry by inserting a bead into an oyster, which acts as an irritant to form the basis of a pearl.

Seine net
A fishing net that hangs vertically in the water column with floats at the top and weights at the bottom, used to enclose schools of fish within the walls of the net.

Division of the body into discrete segments

Selective feeder
An animal that exercises choice over the type of food being taken.

Semidiurnal tides
Two high and two low tides are experienced each day.

Set (Gill) nets
A fishing net which catches fish swimming through with the net material locking around the gill of fish not allowing them to escape.

Distinctive hair-like bristles on female rock lobster swimmerets indicative of breeding condition.

Plants or animals that are permanently attached to a surface.

Hair-like bristles.

Change from a freeswimming form to one that attaches to a substrate

Sexual reproduction
A type of reproduction in which the egg and the sperm combine to form a zygote.

A type of fish with a full cartilaginous skeleton and tough skin covered with small tooth-like scales.

Shelf break
A steep droppoff at the outer edge of the continental shelf, leading into the continental slope.

Aquatic animals with shells, including crustaceans and molluscs.

Shoals (of fish)
Schools of fish, but usually refers to schools at the surface or in shallow water.

To remove a mollusc (i.e. abalone or scallop) from the shell.

States that one object is like another. E.g. The world is like a stage.

Organisms comprising only one cell.

The tube-like extension through which water flows in and out of the mantle cavity in bivalves and cephalopods, and in tunicates.

Size limit
The legislated size which individuals of the prescribed fish species, if caught, are not to be retained.

Slack tide
The occurrence of relatively still water at the turn of the (low) tide

Sea Lion Exclusion Device

State Law Publisher

A substance dissolved into another substance.

A substance in which another substance is dissolved, forming a solution.

Short for Sound Navigation Ranging, sonar is a system that uses transmitted and reflected underwater sound waves (acoustics) to detect and locate submerged objects or measure the distance to the floor of a body of water.

South Equatorial Current
Is predominantly a Southern Hemisphere current that flows westwards across the Pacific, Atlantic and Indian Ocean close to the equator and driven by South East Trade Winds.

Southern Hemisphere
The half of the earth between the South Pole and the equator.

Southern Oscillation Index
Measure of the atmospheric pressure fluctuations between Darwin and Tahiti in an attempt to indicate El Niño and La Niña episodes.

The development stage at which shellfish larvae form shells and settle out of the water column to attach themselves to reefs or the seabed.

Pertaining to space or distance.

The release or depositing of spermatozoa or ova, of which some will fertilise or be fertilised to produce offspring.

Spawning ground
Area where spawning takes place.

Spawning stock biomass
The total weight of all mature fish in a population.

Special purpose zones
Areas that are created to give scientists baseline data. Only certain activities are permitted in these areas. Refer to the specific marine park guide for further information.

A species that thrives in a narrow range of environmental conditions or has a limited diet.

A group of organisms that share common characteristics and are able to breed together to produce offspring capable of reproducing.

Specific gravity
The ratio of the density of a substance to that of water.

The range of colours in visible light.

An opening for breathing, such as a blowhole in a whale or the opening on the head of a shark or ray.

A phylum of sessile animals lacking nerve or muscle cells, a nervous, circulatory or digestive system.

The asexual structure produced by some algae.

Spring tides
Occur when the earth, sun and moon are aligned and the greatest range in tides are experienced.

WA Seafood Quality Management Initiative

Scientific Reference Group

Stagnant (water)
Not running or flowing; to become unclean by standing.

Individual, group or organisation having a valid interest in a field or matter.

State waters
Australia’s Offshore Constitutional Settlement established Commonwealth, State and Territory jurisdictions over marine areas.  States generally have primary jurisdiction over marine areas extending to three nautical miles from the baseline.  For fisheries purposes, the State’s jurisdiction extends out to 200 nautical miles, or to the Asutralian Fishing Zone (AFZ).  Exceptions to this include management of migratory fish, deep water fish species, fisheries which involve overseas interest, and fisheries operating in the waters of more than one State.

A stem-like structure in a nonvascular plant.

A population of fish within a certain geographic area where members of that population breed with each other.

Stock assessment
Process of collecting and analysing biological and statistical information to determine the changes in the abundance of fishery stocks in response to fishing, and, to the extent possible, to predict future trends of stock abundance.

Enlarged muscular sac-like organ for storing, diluting, and digesting food.

The layering of water due to differences in density.

The biological reactions to any negative stimulus either physical, mental or emotional that disturb the animal. These reactions may lead to disorders or disease.

In fishing, the jerk motion by which the fisher secures a fish that is nibbling at the bait and hook.

Of, or relating to the physical makeup of a plant or animal body.

A geological process in which one tectonic plate is forced below another.

Submarine canyons
Narrow, steep-sided valley cut into a continental slope.

Means of support or livelihood.

The layer immediately underneath something or to which it is attached.

Subsurface current
An underwater current that is not present at the surface.

Bordering on tropical areas.

Surface area
Total external surface or total area of an object exposed to the outside environment.

Activities that meet the needs of the present without having a negative impact on future generations. A concept associated with sustainability is triple bottom line accounting, taking into account environmental, social and economic costs.

Sustainable (fish stocks)
Maintenance of a species at a certain stock level.

Sustainable yield (Maximum Sustainable Yield – MSY)
Catch that can be removed over an indefinite period without causing the stock to be depleted.

Swell (waves)
Long-wavelength waves generated by previous winds in other areas, often travelling thousands of kilometres from their origin.

South West Freshwater Research and Aquaculture Centre, Pemberton.

Swim bladder
Air-filled sac that helps fish maintain buoyancy.

Small paddle-like structures under the abdomen of lobsters, prawns and similar crustaceans. They are egg-holding in lobsters, and serve as breathing and movement functions in other crustaceans.

An association of two different organisms which live together and contribute to each other’s support.


Last modified: 11/09/2012 11:46 AM

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