Bathyal zone

Bathyal zone
Aquatic layers
Pelagic
   Photic
      Epipelagic
   Aphotic
      Mesopelagic
      Bathyalpelagic
      Abyssopelagic
      Hadopelagic
Demersal
Benthic
Stratification
Pycnocline
   Isopycnal
   Chemocline
      Halocline
   Thermocline
      Thermohaline
Marine habitats
Lake stratification
Aquatic ecosystems
Wild fisheries
Land habitats
The layers of the pelagic zone.

The bathyal zone or bathypelagic – from Greek βαθύς (bathýs), deep – (also known as midnight zone) is that part of the pelagic zone that extends from a depth of 1000 to 4000 metres (3300 to 13000 feet) below the ocean surface. It lies between the mesopelagic above, and the abyssopelagic below. The average temperature hovers at about 39°F (4°C). Although larger by volume than the euphotic zone, the bathyal zone is less densely populated. Sunlight does not reach this zone, meaning there can be no primary production. It is known as the midnight zone because of this feature. Because of the lack of light, some species do not have eyes, however those possessing eyes in this zone include the viperfish and the frill shark. Many forms of nekton live in the bathyal zone, such as squid, large whales and octopuses, but this zone is difficult for fish to live in. Sponges, brachiopods, sea stars, and echinoids are also common in the bathyal zone. The fish in this zone have become very energy efficient, since it is especially hard to find nutrients. Many have slow metabolic rates to conserve energy. The fish here have weak muscles, soft skin and slimy bodies. Animals in the bathyal zone are not threatened by predators that can see them, so they do not have powerful muscles. Animals need to have the right adaptions to survive in this lethal area. There are no plants because of the lack of sunlight, not enough to for photosynthesis. In the bathyal some of the world's largest whales feed.

Except where the ocean is exceptionally deep, the bathyal zone extends to the benthic zone on the ocean bed of that part of the continental slope that lies between 1000 and 4000 metres deep.

See also

  • Bathypelagic fish

References

  • Enig, C. C. (1997). "Bathyal zones on the Mediterranean continental slope: An attempt". Research on marine benthos: 9th Iberian Symposium on Studies of Marine Benthos. Madrid: MAPA, SGT. pp. 23–33. ISBN 8449102995. 
  • Bathyal zone (oceanography) Encyclopædia Britannica Online. 21 March 2009.



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  • bathyal zone — ▪ oceanography       marine ecologic realm extending down from the edge of the continental shelf to the depth at which the water temperature is 4° C (39° F). Both of these limits are variable, but the bathyal zone is generally described as lying… …   Universalium

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  • bathyal zone — noun the steep descent of the seabed from the continental shelf to the abyssal zone • Syn: ↑continental slope, ↑bathyal district • Hypernyms: ↑ocean floor, ↑sea floor, ↑ocean bottom, ↑seabed, ↑ …   Useful english dictionary

  • bathyal zone — the seafloor at bathyal depths …   Dictionary of ichthyology

  • bathyal zone — /ˈbæθiəl zoʊn/ (say batheeuhl zohn) noun → bathypelagic zone …  

  • typical bathyal zone — noun : the upper half of the bathyal zone …   Useful english dictionary

  • bathyal — [bath′ē əl] adj. [ BATHY + AL] designating or of the ecological zone (bathyal zone) along the continental slope of the ocean floor between c. 100 and 2,000 fathoms ( c. 180 and 3,650 m) …   English World dictionary

  • bathyal district — noun the steep descent of the seabed from the continental shelf to the abyssal zone • Syn: ↑continental slope, ↑bathyal zone • Hypernyms: ↑ocean floor, ↑sea floor, ↑ocean bottom, ↑seabed, ↑se …   Useful english dictionary

  • bathyal — adjective relating to ocean depths between 200 and 2000 meters (corresponds to the continental slope) • Pertains to noun: ↑bathyal zone …   Useful english dictionary

  • bathyal — bathyal, yale, yaux [ batjal, jo ] adj. • v. 1953; du gr. bathus « profond » ♦ Didact. Qui concerne la zone sous marine comprise entre 200 et 2 000 m (correspondant au plateau continental). ● bathyal, bathyale, bathyaux adjectif Se dit des fonds… …   Encyclopédie Universelle

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