Global InformationMarine life information
 | This article contains too many pictures for its overall length. (December 2023) |
| Part of a series of overviews on |
| Marine life |
|---|
 |
|
|
Marine life, sea life, or ocean life is the plants, animals, and other organisms that live in the salt water of seas or oceans, or the brackish water of coastal estuaries. At a fundamental level, marine life affects the nature of the planet. Marine organisms, mostly microorganisms, produce oxygen and sequester carbon. Marine life, in part, shape and protect shorelines, and some marine organisms even help create new land (e.g. coral building reefs).
Most life forms evolved initially in marine habitats. By volume, oceans provide about 90% of the living space on the planet.[2] The earliest vertebrates appeared in the form of fish,[3] which live exclusively in water. Some of these evolved into amphibians, which spend portions of their lives in water and portions on land. One group of amphibians evolved into reptiles and mammals and a few subsets of each returned to the ocean as sea snakes, sea turtles, seals, manatees, and whales. Plant forms such as kelp and other algae grow in the water and are the basis for some underwater ecosystems. Plankton forms the general foundation of the ocean food chain, particularly phytoplankton which are key primary producers.
Marine invertebrates exhibit a wide range of modifications to survive in poorly oxygenated waters, including breathing tubes as in mollusc siphons. Fish have gills instead of lungs, although some species of fish, such as the lungfish, have both. Marine mammals (e.g. dolphins, whales, otters, and seals) need to surface periodically to breathe air.
As of 2023[update], more than 242,000 marine species have been documented, and perhaps two million marine species are yet to be documented. An average of 2,332 new species per year are being described.[4][5]
Marine species range in size from the microscopic like phytoplankton, which can be as small as 0.02 micrometres, to huge cetaceans like the blue whale – the largest known animal, reaching 33 m (108 ft) in length.[6][7] Marine microorganisms, including protists and bacteria and their associated viruses, have been variously estimated as constituting about 70%[8] or about 90%[9][1] of the total marine biomass. Marine life is studied scientifically in both marine biology and in biological oceanography. The term marine comes from the Latin mare, meaning "sea" or "ocean".
- ^ a b Cavicchioli R, Ripple WJ, Timmis KN, Azam F, Bakken LR, Baylis M, et al. (September 2019). "Scientists' warning to humanity: microorganisms and climate change". Nature Reviews. Microbiology. 17 (9): 569–586. doi:10.1038/s41579-019-0222-5. PMC 7136171. PMID 31213707.
Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- ^ Cite error: The named reference
NOAA2019was invoked but never defined (see the help page). - ^ "Tiny Fish May Be Ancestor of Nearly All Living Vertebrates". Live Science. 11 June 2014.
- ^ Drogin, B (2 August 2009). "Mapping an ocean of species". Los Angeles Times. Retrieved 18 August 2009.
- ^ Bouchet, Philippe; Decock, Wim; Lonneville, Britt; Vanhoorne, Bart; Vandepitte, Leen (June 2023). "Marine biodiversity discovery: the metrics of new species descriptions". Frontiers in Marine Science. 10 (3389). doi:10.3389/fmars.2023.929989 – via ResearchGate.
- ^ Paul, GS (2010). "The Evolution of Dinosaurs and their World". The Princeton Field Guide to Dinosaurs. Princeton: Princeton University Press. p. 19. ISBN 978-0-691-13720-9.
- ^ Bortolotti, Dan (2008). Wild blue: a natural history of the world's largest animal. New York: Thomas Dunn Books. ISBN 978-0-312-38387-9. OCLC 213451450.
- ^ Bar-On YM, Phillips R, Milo R (June 2018). "The biomass distribution on Earth". Proceedings of the National Academy of Sciences of the United States of America. 115 (25): 6506–6511. Bibcode:2018PNAS..115.6506B. doi:10.1073/pnas.1711842115. PMC 6016768. PMID 29784790.
- ^ "Census Of Marine Life". Smithsonian. 30 April 2018. Retrieved 29 October 2020.
