Glossary T...

Tacking: Sailing into the wind using a zig-zag motion to maintain a forward course.

Tackle box: Box used by fishers to keep tackle: hooks, sinkers, line, lures, etc.

Tailings: Second grade or waste rock fragments derived from screening or processing or raw ores. Contaminate water quality of streams and rivers.

Temperature: A measurement of the degree of heat or cold of a body or place.

Tentacles: Appendages on sea organisms that contain suckers or stinging cells. Used to grasp food and move around.

Terrestrial: Of the land; living on land.

Territory: Place where an animal lives that it defends.

Test: An outer covering, usually hard, secreted by some organisms

Testis: Male reproductive organs that make sperm.

Tether: A long rope or leash that attaches two things together. The cable that attaches a submersible to a ship is called a tether.

Thallus: The body of a seaweed.

Thermoclines: A zone where the temperature drops rapidly as you descend deeper into the water. You can feel a thermocline if you dive down into a pool.

Thermometer: Instrument used to measure temperature.

Thorax: The chest region of a vertebrate animal, or the central segment of the body of an insect, crustacean or other arthropod.

Threatened species: Plant, animal or micro-organism which may be common in parts of its range but is severely depleted in others.

Throat: Part of a fishing hook.

Throttle: Accelerator handle on an outboard.

Thwarts: Seats of a boat.

Tidal: Between the tides.

Tidal channel: A channel where water rises and falls with the tides.

Tidal current: Circulation of water within coastal embayments caused by changing tides.

Tide pool: A pool of water left along the shore as the tide level falls.

Tidal range: The amount of change in an area's water level from low to high tide.

Tidal zone: The area in which the water moves in a tide.

Tide: Periodic rise and fall of the surface of the ocean and connected bodies of water resulting from the gravitational attraction of the Moon and Sun.

Tilapia: A member of a group of plant-eating freshwater fishes native to Africa; they are easily raised in ponds. If these fish are released into natural waterways they can caused reduction in native fish numbers.

Totem: An object or thing in nature, often an animal, assumed as a token or emblem of a clan, tribe, family or related group.

Tourism: Occupation of providing local services such as entertainment, accommodation and catering for tourists.

Tours: Activity involving taking tourists on a trip.

Toxic: A poison.

Trade winds: The air masses moving from subtropical high-pressure belts toward the equator; south-easterly in the Southern Hemisphere.

Training logbook: Book in which competencies are recorded.

Transect: An area of land or seafloor sectioned off for particular study purposes, usually in the form of a long, continuous strip.

Transformer: A device used to transfer electric energy from one circuit to another.

Transom: The transverse board or planking that forms the stern of a square-ended boat. May have a cut-out or recess.

Transparent: Able to be seen through.

Trawl: A sturdy bag or net that can be dragged along the bottom to catch fish or towed at various depths above the bottom for the same purpose.

Trawler: A fishing boat that tows a trawl net.

Trawling: Fishing by towing a trawl net. Find out more about trawling and see an animation of how it works in Seafood Watch-Gear Types.

Trepang: Sea cucumber. Asian delicacy.

Trichodesmium: Algae responsible for red tides.

Trickle filter: Homemade filtration unit made from plastic scraps and carry boxes.

Trolled: Dragging fishing tackle over or just below the water.

Trophic: Relating to processes of energy and nutrient transfer from one or more organisms to others in an ecosystem.

Trophic level: Position in the food chain; determined by the number of energy-transfer steps.

Trough: (wave) bottom part of wave.

Trout: A member of a group of long-bodied fishes related to salmon. Trout have been important food fish for people for centuries. Many trout species live their entire lives in fresh water, but some spend part of their lives in the sea and return to rivers to spawn.

Tsunami: Large seismic waves produced by earthquakes, volcanic eruptions or underwater landslides (also called tidal waves).

Tube feet: The small projections underneath such animals as starfish which provide them with locomotion.

Tubeworm: Any of a number of species of marine worms or wormlike animals that make a chimneylike tube to live in. In some species the tubes are leathery, in others hard and stony.

Tuna: A group of large, sleek, predatory fishes that wander the open oceans of the world. Many species of tuna are important food fish for people.

Tunicate: Small, primitive chordate animals that live attached to rocks or to the seafloor. Many species of tunicate live in the intertidal zone, and some, like the predatory tunicate, live in the deep sea. Some tunicates are called "sea squirts" because they squirt water when disturbed.

Turbidity: The cloudy conditions caused by the suspended solids in liquid.

Turbidity currents: A quick-moving mixture of water and sediments that travels downslope, scouring the substrate and depositing sediments as it goes.

Twilight zone: In the ocean, the midwater zone of dim light that lies between the sunlit zone and the completely dark, deeper zone.