Data: Information, usually expressed as numbers. ("Data" is actually a plural noun. The singular is "datum." ) Data are often used in analysis to draw conclusions that support or reject a hypothesis.
Debris flows: Relatively slow movement of sediments downward over gently sloping terrain.
Decomposer: An organism, like a bacterium, that causes the decay of dead plant and animal matter.
Deep scattering layer: A concentrated layer of midwater organisms that can reflect and scatter sound waves produced by sonar devices.
Deep sea: The deep, lower regions of the ocean where sunlight doesn't penetrate.
Delaminate: Process by which layers of material come apart by action of salt water and air.
Delegate: (noun) a representative who speaks for a group of people at a meeting or lawmaking assembly. (verb) To give someone authority or responsibility to carry out a task.
Deck: The covered part of the top of a boat.
Decomposer: Organism that breaks down dead tissues, releasing simple chemical substances (minerals) into the environment
Defend: To protect - refers to a territory.
Degrease: Remove grease from engines.
Density: The mass per unit volume of a substance or the number of individuals per unit area.
Deposit feeder: An animal that eats organic matter that's been deposited on or in the seafloor.
Depth sounder: An electronic device that measures the depth of water very precisely.
Desiccation: The loss of water from an organism due to drying in the air or the osmotic stress of a high-salinity environment.
Device: An instrument, tool or machine designed and constructed to perform a certain task.
Diaphragm: A vibrating membrane or disc
used in an aquarium pump to send air in one direction.
single-celled algae which have two ornate interfitting outer 'shells'
display: Display of numbers on an instrument.
Dinghy: A small boat used as a
tender for a larger boat.
Disintegrate: To break up into smaller
Display: A set
of calls or motions done by a bird or animal to convey a particular
message. Penguins might do a courtship display to attract a mate, or an
aggressive display to warn off an enemy.
Dissolved oxygen bottle: Small bottle used
in determining oxygen concentration of a water sample.
Distribution: The range over
which a species lives.
Diving bell: Vessel with compressed air
used in deep sea diving to hold one or more people.
Dogfish: A species of small shark.
Doliolid: A deep sea pelagic tunicate.
member of a group of small whales that have sharp, pointed teeth and
Dorsal: On or toward the back or topside
(opposite of ventral).
Dragging: Another term for bottom trawling,
a fishing method in which large nets are dragged along the seafloor to
spraying: To paint a sign with a stencil on a drain to
increase public awareness about stormwater pollution.
Dreamtime: Time in Aboriginal
spiritual culture during which the Earth received its present form and
in which the patterns and cycles of life and nature were
net attached to a frame that's dragged along the ocean floor to collect
Drift kelp: A
piece of seaweed that breaks free of its holdfast, drifts with the
ocean currents and sinks to the seafloor.
Drop in: To catch a wave in front of another surfer who is already on the wave. Dangerous practice often leading to surfing injuries.
Duck diving: To push your board under a broken wave so as to avoid the break.
Dune: A hill of sand. The wind pushes sand from the beach into dunes.