GLOSSARY
Abyssal. Between 3000 and 6000 m deep; the abyssal
plain.
Aleurites. A term used primarily in the Russian
literature referring to silt-sized particles.
Authigenic. Minerals formed where they are now
found; the products of chemical and biochemical
action.
Barophilic. Those organisms that can only live at high
pressure and do not survive at low pressure; literally,
“lover of pressure”.
Bathyal. Between ~200 and 3000 m deep; the continental slope.
Benthic lander. Any piece of apparatus that is freefloated to the seabed, carries out observations or
analysis, and floats to the surface on weight release.
Benthopelagic. The zone in the water column immediately above the sea bed. It often has its own distinct
fauna.
Box corer. A piece of equipment for taking a square
core from the seabed with an area of 0.25 m
2 .
The main apparatus used for quantitative deep-sea
benthic ecology.
Calcium carbonate compensation depth. The depth
at which calcium carbonate goes into solution.
Depocentre. An area or site of maximum deposition.
Diagenetic process. The compression and hardening of
sediment into rock.
Diapir. A salt dome in sediment, often associated with
oil deposits.
Diatreme. A volcanic vent or pipe drilled through
enclosing rocks by the explosive energy of gascharged magma.
Ekman layer. A layer in which water is moved to
the right (northern hemisphere) or left (southern
hemisphere) of the wind direction.
Epibenthic sledge. A sampling apparatus towed over
the seabed using a fine mesh as a filter.
Epibenthos. Those animals living on the surface of the
seabed.
Eurybathic. Having a wide depth range.
Hadal. Deeper than 6000 m; the oceanic trenches.
Hemipelagic. Silt-sized fraction of sediment found on
or near continental margins composed of plankton
flux and terrigenously derived material.
Hyperbenthic. Those animals living in the water
column immediately above the seabed; cf. benthopelagic, suprabenthos.
Ladder of migration. term for the overlapping vertical
distribution of pelagic species down through the
water column.
Macrobenthos. Animals retained by an 0.5 mm sieve
but not visible in bottom photographs; cf. macrofauna.
Macrofauna. Animals retained by an 0.5 mm sieve.
Macroinfauna. Macrofauna living in the sediment.
Macroplankton. Zooplankton with dimensions between 200 mm and 2 mm.
Macrophyte. Large plant material in the sea, usually
algae but occasionally flowering plants.
Marine snow. Aggregates of organic and inorganic
particles sinking through the water column.
Mass wasting. The slippage of large amounts of
sediment down the continental slope.
Megafauna. Those animals on the seabed visible to the
camera.
Mega-infauna. Large animals burrowed in the sediment.
Megaturbidite. A very large turbidite.
Meiofauna. Those animals that pass through a 0.5 mm
sieve.
Mesopelagic. The zone in the water column between
~400 and 1000 m depth.
Microbiota. Microorganisms, usually unicellular, especially bacteria.
Micronekton. Small swimming organisms in the water
column.
Nekton. Organisms that swim in the water column, e.g.
fish, cetaceans, squid.
Nepheloid. A turbid layer of water immediately above
the seabed or associated with a physical discontinuity
such as a thermocline.
Neuston. Organisms living at the immediate water/air
interface; often blue in colour.
Opal flux. The flux of silica to the seabed.
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Abyssal. Between 3000 and 6000 m deep; the abyssal
plain.
Aleurites. A term used primarily in the Russian
literature referring to silt-sized particles.
Authigenic. Minerals formed where they are now
found; the products of chemical and biochemical
action.
Barophilic. Those organisms that can only live at high
pressure and do not survive at low pressure; literally,
“lover of pressure”.
Bathyal. Between ~200 and 3000 m deep; the continental slope.
Benthic lander. Any piece of apparatus that is freefloated to the seabed, carries out observations or
analysis, and floats to the surface on weight release.
Benthopelagic. The zone in the water column immediately above the sea bed. It often has its own distinct
fauna.
Box corer. A piece of equipment for taking a square
core from the seabed with an area of 0.25 m
2 .
The main apparatus used for quantitative deep-sea
benthic ecology.
Calcium carbonate compensation depth. The depth
at which calcium carbonate goes into solution.
Depocentre. An area or site of maximum deposition.
Diagenetic process. The compression and hardening of
sediment into rock.
Diapir. A salt dome in sediment, often associated with
oil deposits.
Diatreme. A volcanic vent or pipe drilled through
enclosing rocks by the explosive energy of gascharged magma.
Ekman layer. A layer in which water is moved to
the right (northern hemisphere) or left (southern
hemisphere) of the wind direction.
Epibenthic sledge. A sampling apparatus towed over
the seabed using a fine mesh as a filter.
Epibenthos. Those animals living on the surface of the
seabed.
Eurybathic. Having a wide depth range.
Hadal. Deeper than 6000 m; the oceanic trenches.
Hemipelagic. Silt-sized fraction of sediment found on
or near continental margins composed of plankton
flux and terrigenously derived material.
Hyperbenthic. Those animals living in the water
column immediately above the seabed; cf. benthopelagic, suprabenthos.
Ladder of migration. term for the overlapping vertical
distribution of pelagic species down through the
water column.
Macrobenthos. Animals retained by an 0.5 mm sieve
but not visible in bottom photographs; cf. macrofauna.
Macrofauna. Animals retained by an 0.5 mm sieve.
Macroinfauna. Macrofauna living in the sediment.
Macroplankton. Zooplankton with dimensions between 200 mm and 2 mm.
Macrophyte. Large plant material in the sea, usually
algae but occasionally flowering plants.
Marine snow. Aggregates of organic and inorganic
particles sinking through the water column.
Mass wasting. The slippage of large amounts of
sediment down the continental slope.
Megafauna. Those animals on the seabed visible to the
camera.
Mega-infauna. Large animals burrowed in the sediment.
Megaturbidite. A very large turbidite.
Meiofauna. Those animals that pass through a 0.5 mm
sieve.
Mesopelagic. The zone in the water column between
~400 and 1000 m depth.
Microbiota. Microorganisms, usually unicellular, especially bacteria.
Micronekton. Small swimming organisms in the water
column.
Nekton. Organisms that swim in the water column, e.g.
fish, cetaceans, squid.
Nepheloid. A turbid layer of water immediately above
the seabed or associated with a physical discontinuity
such as a thermocline.
Neuston. Organisms living at the immediate water/air
interface; often blue in colour.
Opal flux. The flux of silica to the seabed.
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