pelagic zone


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Related to pelagic zone: Benthic zone

pelagic zone:

see oceanocean,
interconnected mass of saltwater covering 70.78% of the surface of the earth, often called the world ocean. It is subdivided into four (or five) major units that are separated from each other in most cases by the continental masses. See also oceanography.
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Pelagic Zone

 

that part of a lake, sea, or ocean that is the habitat of pelagic organisms—plankton, necton, and pleuston. The pelagic zone is opposed to the benthic zone, that is, the bottom of the body of water, which is inhabited by benthos.

In oceans and seas, the pelagic zone is divided horizontally into two regions: the neritic (water above the shelf) and the oceanic (all the remaining water). Vertically the zone is divided, usually depending on the degree of illumination, into three regions: the euphotic (well illuminated), the dysphotic (feebly illuminated), and the aphotic (lightless). The zone is also broken down according to the distribution of life into the epipelagic, mesopelagic, and deep-water regions. In freshwaters, the pelagic zone is divided horizontally into two regions: the shore region (the water near the shore) and the pelagic region proper (all the remaining water). Vertically three regions are distinguished according to the rate of temperature drop: the epilimnion, the metalimnion, and the hypolimnion.

References in periodicals archive ?
A series of experiments with vertical longlines were designed to catch the species in the pelagic zone, and information on individual depth trajectories were obtained from archival tags for comparisons with the vertical distribution of longline catches.
This is in contrast to a study by Jorgensen (1997), who found that although one- and two-year-old Greenland halibut from West Greenland nursery areas were found in high abundance in pelagic waters, larger fish (>52 cm) were not found in the pelagic zone of the area inhabited by adult fish.
Whatever the reason, the pelagic zone is where most eggs go, where they hatch into larvae, and where they then join the legions of zooplankton.
The pelagic zone, where the surgeonfish and the Napoleon begin their lives, doesn't appear vitally connected to coral reefs.
sierra is a carnivorous ichthyophagous predator in the coastal pelagic zone, consuming mainly species from the families Clupeidae and Engraulidae, and a lower proportion of cephalopods (squid).
Low DO concentrations in the hypolimnion, during the warm season, in the pelagic zone, certainly limited the vertical distribution of the organisms, but did not interfere in the horizontal distribution.
The planktonic species were either indistinctly distributed in the three stations or preferentially located in the pelagic zone, where the invertebrate predators, chaoborids and mites, are more abundant.
Chydorus sphaericus and Bosmina longirostris are usually found in both littoral and pelagic zones. Furthermore, seven Copepoda species are characteristic for vegetation stands and only one is described as strictly pelagic (Table I).
Values of zooplankton [[delta].sup.13]C identified the aquatic macrophytes as a differentiated zone regarding zooplankton feeding behaviour, with a mean of -27.31[per thousand], much more enriched than the zooplankton of the littoral and pelagic zones, with had values of -33.11 and -34.66[per thousand], respectively (Fig.