Key Vocabulary
Secchi Disk - used to estimate the transparency of seawater, can give a relative measure of
productivity or turbidity
Seine Net - a fishing net that hangs vertically in the water with its bottom edge held down by
weights and its top edge buoyed by floats
Sediment Sieves - used to analyze sediment grain size composition
Plankton Net - a fine mesh net, collects small plant and animal plankton, typically towed behind
or to the side of a vessel
Neuston Net - used to collect organisms and other particulates from the surface to about 1 ½ feet
down
Tucker Trawl - used to collect samples at various depths, insures that only what is caught in the
net is at the specified depth
Niskin Bottle - used to collect water samples from specific depths
Hydrophone - a microphone for acoustic measurements in fluids
Bottom Grab Sampler - used to take samples from off the ocean floor; sediment, as well as any
organisms on the substrate, will be collected when it closes
Dredge - used to catch organisms living on the ocean floor and right above it, towed behind the
vessel
Hydrometer - device used to measure the densities of liquid and solutions, salinity levels are
determined with this instrument
Refractometer - in terms of oceanography, a refractometer is used to measure the salinity and
specific gravity of the water
Buoys - a floating device that can have many purposes including weather transmission, water
quality tests, channel markers, life- saving, etc.
GPS (Global Positioning System) - a worldwide radio-navigation system that uses satellites to
triangulate your location on earth
ROV (Remotely Operated Vehicles) - unoccupied, highly maneuverable underwater robots
operated by a person aboard a surface vessel
Satellite - an artificial body placed in orbit around the earth in order to collect information
SCUBA (Self-Contained Underwater Breathing Apparatus) - an apparatus used in diving,
consisting of a cylinder or cylinders containing compressed air attached to a breathing apparatus
Latitude – the distance of a place north or south of the earth's equator
Longitude – the distance of a place east or west of the Prime Meridian
Ocean Basin – a great depression occupied by the ocean on the surface of the lithosphere
Geological Oceanography – the branch of oceanography that studies coastal processes, below
the ocean’s surface & what formed the ocean’s basins
Biological Oceanography - the branch of oceanography that investigates life in the ocean
Chemical Oceanography – the branch of oceanography that studies the dissolved elements in
seawater and the ocean's chemical and biochemical cycles
Physical Oceanography – the branch of oceanography that studies how & why the oceans
move, including waves, tides, & currents
Environmental Oceanography – the branch of oceanography that studies the effects of human
activities on the ocean environment
Ocean Engineering - the branch of engineering that deals with the development of equipment
and techniques for the exploration of the ocean floor and exploitation of its resources
Brackish Water - water that has a higher salinity than fresh water, but a lower salinity than
saltwater, typically between 0.5ppt & 17ppt
Saltwater –water that has a salinity greater than 17ppt
Salinity – the amount of dissolved salts in water
pH – the measure of the acidity or alkalinity of a solution