The pelagic zone consists of the
The pelagic zone contrasts with the
Depth and layers
The pelagic zone is subdivided into five vertical regions. From the top down, these are:
The illuminated zone at the surface of the sea with sufficient light for photosynthesis. Nearly all primary production in the ocean occurs here, and marine life is concentrated in this zone, including plankton, floating seaweed, jellyfish, tuna, many sharks and dolphins.
The most abundant organisms thriving into the mesopelagic zone are heterotrophic bacteria. Animals living in this zone include swordfish, squid, wolffish and some species of cuttlefish. Many organisms living here are bioluminescent. Some mesopelagic creatures rise to the epipelagic zone at night to feed.
The name stems from
Abyssopelagic (abyssal zone)
The name is derived from
Hadopelagic (hadal zone)
The name is derived from the realm of
The pelagic ecosystem is based on phytoplankton. Phytoplankton manufacture their own food using a process of photosynthesis. Because they need sunlight, they inhabit the upper, sunlit epipelagic zone, which includes the coastal or neritic zone. Biodiversity diminishes markedly in the deeper zones below the epipelagic zone as dissolved oxygen diminishes, water pressure increases, temperatures become colder, food sources become scarce, and light diminishes and finally disappears.
Some examples of pelagic invertebrates include
Pelagic fish live in the water column of coastal, ocean, and lake waters, but not on or near the bottom of the sea or the lake. They can be contrasted with demersal fish, which do live on or near the bottom, and coral reef fish.
Pelagic fish are often migratory forage fish, which feed on plankton, and the larger predatory fish that follow and feed on the forage fish. Examples of migratory forage fish are herring, anchovies, capelin, and menhaden. Examples of larger pelagic fish which prey on the forage fish are billfish, tuna, and oceanic sharks.
Hydrophis platurus, the yellow-bellied sea snake, is the only one of the 65 species of marine snakes to spend its entire life in the pelagic zone. It bears live young at sea and is helpless on land. The species sometimes forms aggregations of thousands along slicks in surface waters. The yellow-bellied sea snake is the world's most widely distributed snake species.
Many species of sea turtles spend the first years of their lives in the pelagic zone, moving closer to shore as they reach maturity.
Pelagic birds, also called oceanic birds or seabirds, live on open seas and oceans rather than inland or around more restricted waters such as rivers and lakes. Pelagic birds feed on planktonic crustaceans, squid and forage fish. Examples are the Atlantic puffin, macaroni penguins, sooty terns, shearwaters, and Procellariiformes such as the albatross, Procellariidae and petrels.
- ^ "pelagic (adj.)". Online Etymology Dictionary. Retrieved 17 February 2020.
- PMID 21033734.
- ^ Ocean's Depth and Volume Revealed Archived 23 August 2011 at the Wayback Machine OurAmazingPlanet, 19 May 2010.
- ^ a b c The Open Ocean - MarineBio.org
- ISBN 978-0-8160-5705-4.
- ^ Thorson, G (1957). "Bottom communities (sublittoral or shallow shelf)". In Hedgpeth, J.W. (ed.). Treatise on Marine Ecology and Palaeoecology. Geological Society of America. pp. 461–534.
- S2CID 84623588.
- ISBN 978-0-8248-2265-1.
- doi:10.3389/fmars.2017.00222..Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License
- Ryan, Paddy "Deep-sea creatures" Te Ara – the Encyclopedia of New Zealand, updated 21 September 2007
- "Pelagic-zone (oceanography)" Encyclopædia Britannica Online. 21 March 2009.
- Grantham HS, Game ET, Lombard AT, et al. (2011) "Accommodating Dynamic Oceanographic Processes and Pelagic Biodiversity in Marine Conservation Planning"
- Wrobel, David; Mills, Claudia (2003) . Pacific Coast Pelagic Invertebrates: A Guide to the Common Gelatinous Animals. Sea Challengers and Monterey Bay Aquarium. ISBN 0-930118-23-5.