Milankovitch theory
196
ble of migration have a sense of direction (~orientation) and are able to move
actively. Movements that do not include an obligatory return journey have
been classed as dispersal, e.g., young that leave the area of birth and settle
elsewhere (natal dispersal), or animals that have reproduced once in one
area and use another area the next time (breeding dispersal). ~orientation,
~homing, and ~scattering layer.
Milankovitch theory a theory of glaciation, formulated in 1941 by the Yugoslav
mathematician Milutin Milankovitch (1879-1958). This theory states that
climatic changes result from fluctuations in the geographic and temporary
distribution of insolation, determined by orbital variations.
mile ~nautical mile.
mimicry resemblance to organisms of other species, either to advertise an effective protective device that they possess in common with other species
(Mullerian mimicry), or to "pretend" they possess such a device when they
actually do not (Batesian mimicry). ~coloration in (marine) animals.
mineralization the degradation of organic matter by organisms. During this
process minerals (plant nutrients) become available again to the primary
producers. ~decomposition.
mineral resources because of technologic and economic limits the mining of
marine resources is mainly restricted to the continental shelves. Hydrocarbons (oil and gas) make up almost 90 % of the current subsea mineral production. Other mineral resources of the continental shelves include heavymineral concentrates, gravel, shell, and lime mud mined by dredging in shallow water. Sulfur and salt are mined through drill holes. Phosphorite, potash,
magnesium, fresh ground water, and geothermal energy (recoverable through
drill holes) are other minerals that may be brought into production from the
continental shelves in the future. The manganese nodules that occur on the deep
ocean floor are an enormous potential source of manganese, copper, nickel,
cobalt, zinc and other metals. Exploration of the nodules, however, is not economically feasible yet because the mining of land resources is much cheaper.
minimum biologically acceptable level (MBAL) value of spawning stock biomass
above which there is no empirical evidence that recruitment is dependent on
egg production. Below this level the probability of poor recruitment increases.
Miocene ~geological time scale.
mitochondria cell organelles of eukaryotic organisms responsible for processes of
respiration and electron-transport phosphorylation.
196
ble of migration have a sense of direction (~orientation) and are able to move
actively. Movements that do not include an obligatory return journey have
been classed as dispersal, e.g., young that leave the area of birth and settle
elsewhere (natal dispersal), or animals that have reproduced once in one
area and use another area the next time (breeding dispersal). ~orientation,
~homing, and ~scattering layer.
Milankovitch theory a theory of glaciation, formulated in 1941 by the Yugoslav
mathematician Milutin Milankovitch (1879-1958). This theory states that
climatic changes result from fluctuations in the geographic and temporary
distribution of insolation, determined by orbital variations.
mile ~nautical mile.
mimicry resemblance to organisms of other species, either to advertise an effective protective device that they possess in common with other species
(Mullerian mimicry), or to "pretend" they possess such a device when they
actually do not (Batesian mimicry). ~coloration in (marine) animals.
mineralization the degradation of organic matter by organisms. During this
process minerals (plant nutrients) become available again to the primary
producers. ~decomposition.
mineral resources because of technologic and economic limits the mining of
marine resources is mainly restricted to the continental shelves. Hydrocarbons (oil and gas) make up almost 90 % of the current subsea mineral production. Other mineral resources of the continental shelves include heavymineral concentrates, gravel, shell, and lime mud mined by dredging in shallow water. Sulfur and salt are mined through drill holes. Phosphorite, potash,
magnesium, fresh ground water, and geothermal energy (recoverable through
drill holes) are other minerals that may be brought into production from the
continental shelves in the future. The manganese nodules that occur on the deep
ocean floor are an enormous potential source of manganese, copper, nickel,
cobalt, zinc and other metals. Exploration of the nodules, however, is not economically feasible yet because the mining of land resources is much cheaper.
minimum biologically acceptable level (MBAL) value of spawning stock biomass
above which there is no empirical evidence that recruitment is dependent on
egg production. Below this level the probability of poor recruitment increases.
Miocene ~geological time scale.
mitochondria cell organelles of eukaryotic organisms responsible for processes of
respiration and electron-transport phosphorylation.