anoxic: without oxygen
aphotic zone: The deep part of the ocean in which sunlight is absent
attenuation: a decrease in the energy of light due to absorption and scattering in the water column
BATS: Bermuda Atlantic Time Series Study
BBOP: Bermuda Bio-Optics Program
biogeochemical: short for biological, geological, and chemical; often used to describe cycling of elements in the sea (i.e., biogeochemical cycling)
bioluminescence: the production of light by living organisms. Common among deep-sea creatures
biomass: the number of organisms in an area or volume multiplied by the average weight of the individuals
bio-optics: study of how living organisms (e.g., phytoplankton) affect light in the sea
bloom: the sudden appearance of a high concentration of phytoplankton resulting from increased reproduction due to favorable conditions
blue-water: refers to open-ocean, oligotrophic conditions
carnivore: an animal that eats other animals
carotenoid: a plant "accessory" pigment that captures sunlight for photosynthesis
chemosynthesis: fixation of carbon from CO2 into organic compounds using energy from oxidation of inorganic compounds such as ammonia, methane, and hydrogen sulfide. Compare with photosynthesis
chlorophyll: a group of plant pigments that capture sunlight for photosynthesis
CO2: carbon dioxide, an important greenhouse gas and part of the carbon cycle
conductivity: a measure of how well sea water conducts electricity. Conductivity increases with increasing salinity, and is thus used to measure salinity indirectly
decomposer: an organism that breaks down dead organic material into inorganic forms
deep scattering layer: a dense layer of marine organisms that reflect sound waves
depth profile: a graph that shows how a property of sea water changes with depth
diatoms: single-celled phytoplankton with an external skeleton made of silica
diel: refers to events that occur on a daily or 24-hour cycle
DOC: abbreviation for dissolved organic carbon
DOM: abbreviation for dissolved organic matter
DON: abbreviation for dissolved organic nitrogen
downwelling: the sinking of water
egest: to void unused food as feces. Commonly known as pooping.
euphotic: refers to the surface layer of the ocean that receives enough sunlight for photosynthesis
excretion: the elimination of wastes produced during metabolism, usually as urea or ammonia. Commonly known as peeing.
fluorometer: a device used to measure the fluorescence of phytoplankton chlorophyll; used to determine phytoplankton biomass in the sea
gyre: a circular motion of water with a diameter of 1000s of kilometers (larger than an eddy)
halocline: the vertical zone showing the greatest change in salinity with depth
herbivore: an animal that eats plants
hydrostatic pressure: the pressure exerted at a given depth by the weight of the overlying column of water
hydrowire: a strong cable containing electrical wires that is used to tow or deploy oceanographic research equipment, such as a CTD, from a ship. The electrical wires allow communication between the ship and the research equipment.
marine snow: aggegrations of detritus, visible to the naked eye, that consist of dead organisms, discarded feeding structures, fecal pellets, and other organic debris
mesopelagic zone: the portion of the water column between about 200 and 1000 meters depth
micronutrient: nutrients required by a plant in relatively small concentrations for growth (e.g., iron) , as opposed to macronutrients like nitrate and phosphate which are required in higher concentrations
mineralization: the breakdown of organic compounds into inorganic materials
mixed layer: a layer of surface water that is mixed by the wind and is thus isothermal
multicellular: refers to organisms that are made up of more than one cell (compare unicellular)
nekton: pelagic animals capable of swimming against a current such as fish and marine mammals
nematocysts: stinging cells on the tentacle of a jellyfish
Niskin bottle: a tube that can be triggered to close and collect water at different depths
nutrient: organic or inorganic materials used in the nutrition of primary producers
omnivore: an animal that eats both plants and other animals
oxygen minimum layer: a vertical zone in the water column where the concentration of dissolved oxygen gas is low, usually between 400-800 meter deep. .
PAR: abbreviation for Photosynthetically Active Radiation, refers to the wavelengths of sunlight that plants can use to power photosynthesis.
pelagic: refers to the water column and the organisms living there
piscivore: an animal that primarily eats fish
pleuston: marine organisms such as the Portuguese Man oŽ War that float at the sea surface and project partly into the air
POC: an abbreviation for Particulate Organic Carbon
red tide: a red patch of sea water caused by high concentrations of dinoflagellates, toxins released by the dinoflagellates can make the water poisonous to other marine organisms
salinity: a measure of the saltiness of water
salinometer: a device used to measure salinity
salps: barrel-shaped, gelatinous zooplankton
sink: refers to a region that takes up a greater amount of some substance than it releases. For instance, some ocean areas are carbon sinks, because they absorb more carbon dioxide gas from the atmosphere than they release back to the atmosphere (compare source).
source: refers to a region that releases more of some substance than it takes up. For instance, some ocean areas are carbon sources, because they release more carbon dioxide gas to the atmosphere than they absorb from the atmosphere (compare sink).
thermocline: the vertical zone in the water column where temperature changes rapidly with depth
time series: a graph that shows how some property or value changes through time
titrator: an instrument that determines the concentration of a substance in a solution by slowly adding a standard reagent of known concentration until a reaction is completed as shown by a color change or electrical measurement
ultraviolet (UV) radiation: invisible wavelengths of light of less than about 380 nanometers (a nanometer equals one-thousandth of a micron)
unicellular: refers to organisms composed of a single cell (compare multicellular)
upwelling: a rising of nutrient-rich water toward the sea surface
water column: refers to a vertical expanse of sea water stretching from the ocean surface to just above the ocean floor, habitat for pelagic organisms
water mass: a discrete region or volume of sea water that exhibits consistent physical properties such as temperature and salinity. Different water masses tend to mix together very slowly.