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pelagic sediments
resulting in the inclusion of colloids, small bacteria, and other particles,
both living and dead, in the dissolved fraction . ~carbon, organic.
particulate organic matter (POM) the fraction of total organic matter that can be
filtered or centrifuged from seawater, leaving dissolved organic matter (DOM)
behind. Hence the difference between particulate and dissolved organic
matter is arbitrary. ~carbon, organic.
passive continental margin ~continental margin.
passive drift ~drift.
patchiness clustered occurrence of organisms. Causes are nonrandom distribution of physical and chemical properties of the environment, or certain
behavioral patterns in organisms. Patchiness is one of the main difficulties
in the interpretation of quantitative samples.
pathogen organism, e.g., a parasite, bacterium or virus, which causes disease.
P/B ratio ~turnover rate.
pearls hard structures of calcium carbonate and protein produced around an
irritant inside the nacreous layer of Mollusca such as the pearl oyster (Pinctada
margaritifera). Cultivated pearls are produced in captured oysters by inserting a graft into the gonads. Pearl-like structures produced by nonnacreous
mollusks such as the queen conch (Strom bus gigas) or the giant clam
(Tridacna maxima) are not considered to be true pearls.
pelagic the aquatic environment in deeper fresh or marine waters, of which the
bottom and the benthic layer make no part. In purely pelagic circumstances,
there are only vertical gradients, like those of light, temperature, and salinity. These three gradients together with gravity may be the only cues for orientation of animals and plants. This means that life in the pelagic environment requires special adaptations such as those to prevent sinking. The
term pelagic is widely used to indicate that certain organisms are adapted to
live in the pelagic: pelagic plants are the planktonic algae, pelagic animals
are micro-, meso- and macroplankton; pelagic fish are those living in the
water column. Various depth zones can be discerned in the pelagic environment (~zonation). Usually marine ecosystems are divided into two different
compartments: the benthic system at the bottom and the pelagic system in
the overlying water column.
pelagic sediments ~deep-sea sediments.
pelagic sediments
resulting in the inclusion of colloids, small bacteria, and other particles,
both living and dead, in the dissolved fraction . ~carbon, organic.
particulate organic matter (POM) the fraction of total organic matter that can be
filtered or centrifuged from seawater, leaving dissolved organic matter (DOM)
behind. Hence the difference between particulate and dissolved organic
matter is arbitrary. ~carbon, organic.
passive continental margin ~continental margin.
passive drift ~drift.
patchiness clustered occurrence of organisms. Causes are nonrandom distribution of physical and chemical properties of the environment, or certain
behavioral patterns in organisms. Patchiness is one of the main difficulties
in the interpretation of quantitative samples.
pathogen organism, e.g., a parasite, bacterium or virus, which causes disease.
P/B ratio ~turnover rate.
pearls hard structures of calcium carbonate and protein produced around an
irritant inside the nacreous layer of Mollusca such as the pearl oyster (Pinctada
margaritifera). Cultivated pearls are produced in captured oysters by inserting a graft into the gonads. Pearl-like structures produced by nonnacreous
mollusks such as the queen conch (Strom bus gigas) or the giant clam
(Tridacna maxima) are not considered to be true pearls.
pelagic the aquatic environment in deeper fresh or marine waters, of which the
bottom and the benthic layer make no part. In purely pelagic circumstances,
there are only vertical gradients, like those of light, temperature, and salinity. These three gradients together with gravity may be the only cues for orientation of animals and plants. This means that life in the pelagic environment requires special adaptations such as those to prevent sinking. The
term pelagic is widely used to indicate that certain organisms are adapted to
live in the pelagic: pelagic plants are the planktonic algae, pelagic animals
are micro-, meso- and macroplankton; pelagic fish are those living in the
water column. Various depth zones can be discerned in the pelagic environment (~zonation). Usually marine ecosystems are divided into two different
compartments: the benthic system at the bottom and the pelagic system in
the overlying water column.
pelagic sediments ~deep-sea sediments.