MARINE MICRO TERMS

Question 1

Algae

Answer 1

Organisms having chlorophyll a as a photosynthesis pigment and which have no root, stem, or leaf systems. It includes phytoplankton (including cyanobacteria = Cyanophtya = blue-green algae) and macroalgae. It is not a valid taxonomic grouping in an evolutionary sense.

Question 2

Detritus

Answer 2

Dead particulate organic matter.

Question 3

Neuston

Answer 3

Organisms closely associated with the sea surface; usually floating or small enough to be attached to the meniscus.

Question 4

Plankton

Answer 4

Plants (phyto-), animals (zoo-), bacteria (bacterio-), and viruses (virio-) suspended, floating, or having insufficient swimming abilities to avoid transport by major water movements.

Question 5

aphotic

Answer 5

the region in which no detectable light occurs. It is associated with the abyssal sea-floor zone = Bathypelagic.

Question 6

Coastal

Answer 6

near the coast, usually not precisely defined

Question 7

Compensation depth

Answer 7

the depth at which photosynthesis and respiration of the phytoplankton community are balanced, not for the water column, but for that depth

Question 8

Euphotic / photic

Answer 8

The layer of the ocean illuminated by sunlight. Its lower boundary can be defined as the compensation depth, but it is usually defined as the depth at which 1% or 0.1% of the surface light is remaining.

Question 9

Halocline

Answer 9

Region of maximum change in salinity with depth.

Question 10

Littoral

Answer 10

The shore region between highest and lowest tides = intertidal

Question 11

Neritic

Answer 11

The zone lying between the coast and edge of the continental shelf (shelf break); sometimes taken as the 200m isobath.

Question 12

Oceanic

Answer 12

the ocean beyond the neritic zone

Question 13

Pelagic

Answer 13

Free-living in the water column as opposed to attached to substrate

Question 14

Pycnocline

Answer 14

Region of maximum change in density with depth

Question 15

Thermocline

Answer 15

Region of maximum temperature change with depth

Question 16

Water column

Answer 16

The water directly under a specific area on the surface; i.e. a profile through the water starting at the surface.

Question 17

Autotroph

Answer 17

‘self feeding’; growth derived from simple inorganic components, usually using solar energy (e.g. photo-, chemo-)

Question 18

Auxotroph

Answer 18

an autotroph which has an obligate requirement for organic compounds (e.g. vitamins)

Question 19

Bactivor or bacterivore

Answer 19

an organisms which consumes bacteria

Question 20

Barophile

Answer 20

an organism which can only persist at pressures found at great depths

Question 21

chemoautotroph

Answer 21

inorganic compounds serve both as carbon and energy sources = chemolithotroph

Question 22

chemoheterotroph

Answer 22

organic compounds serve both as sources of carbon and as the sole sources of energy (= chemoorganotroph)

Question 23

eutrophic

Answer 23

waters of relatively high nutrient concentrations, standing stocks and productivity. Eutrophication is the process where nutrient inflow into a body of water causes an increase in phytoplankton standing stock and overall productivity.

Question 24

Food Chain

Answer 24

a sequence of organisms used to indicate the transfer of material or energy (or both)

Question 25

Food web

Answer 25

the complex feeding inter-relationships normally found in an ecosystem

Question 26

Grazer

Answer 26

a feeder on relatively passive food, usually plant material, but it can also apply to feeding on bacteria (i.e. secondary producer)

Question 27

Herbivore

Answer 27

A feeder on photosynthetic food (i.e. plant, autotroph, primary producer) = secondary producer

Question 28

Heterotroph

Answer 28

‘mixed feeding’; organisms deriving their raw materials and energy from organic sources. Many different types are known, and this term is therefore useful only in its broadest sense.

Question 29

Myxotroph

Answer 29

an organisms capable of more than one type of feeding, such as an autotrophic organisms which also captures living food as a dietary supplement (also unfortunately used by some microbiologists as synonymous with auxotrophy)

Question 30

oligotroph

Answer 30

an organism which can only grow at very low substrate concentrations

Question 31

oligotrophic

Answer 31

areas of low nutrient concentrations, standing stocks and productivity. Typical of tropical offshore waters.

Question 32

phagotroph

Answer 32

unicellular organisms that ingest prey using food vacuoles (e.g. heterotrophic flagellates)

Question 33

photoautotroph (=photolithotroph)

Answer 33

an organisms in which the major and indispensable source of carbon is inorganic (usually CO2), deriving its energy from light. Many are also auxotrophs

Question 34

Photoheterotroph:

Answer 34

organic substances serve as the sources of carbon; light is the principal energy source (e.g. a non-sulfur purple bacterium), = photoorganotroph

Question 35

primary producer

Answer 35

= autotroph; synthesize high-energy organic compounds from low energy inorganic compounds; either energy from light (photoautotrophic or photolithotroph) or chemical (chemautotroph or chemolithotroph) energy from oxidation or inorganic comounds is used. Photoautotrophs are the most important primary producers in the ocean.

Question 36

primary productivty

Answer 36

the rate of increase (or if negative, decrease) of primary producers (dn/dt where n is a measure of the biomass of the primary producers), commonly expressed in terms of the amount of C ‘fixed’ (incorporated into living material) per unit time (t). The can be given as gross or net, depending on whether losses due to respiration are subtracted or not.