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{{Short description|Scientific study of organisms that live in the ocean}}
[[organism]]s in
{{for|the scientific journal|Marine Biology (journal)}}
== Headline text ==U R A LOSER!!!!!!!
{{redirect|Marine biologist|the Seinfeld episode|The Marine Biologist}}
the [[ocean]] or other [[Marine (ocean)|marine]] or [[brackish]] bodies of water. Given that in [[biology]] many [[scientific classification|phyla]], families and genera have some species that live in the [[sea]] and others that live on land, marine biology classifies species based on the [[environment (biophysical)|environment]] rather than on [[taxonomy]]. Marine biology differs from [[marine ecology]] as marine [[ecology]] is focused on how organisms interact with each other and environment and [[biology]] is the study of the animal it self.
{{multiple image|perrow = 2|total_width=350
| image1 = Tide pools in santa cruz.jpg
| image2 = Chevron_Baracuda.JPG
| image3 = HCMR submarine.jpg
| image4 = Fan_mussel_(Pinna_nobilis).jpg
| footer = Marine biology studies species ([[marine life]]) that live in [[Marine habitat|marine habitats]] ([[coastal]] and [[open ocean]] habitats). Clockwise from top left: [[Tide pool]] in [[Santa Cruz, California|Santa Cruz]], United States; School of [[barracuda]] at [[Pom Pom Island]], Malaysia; [[Fan mussel]] in a [[Mediterranean Sea|Mediterranean]] [[seagrass meadow]]; Research [[submarine]] for marine research.
}}
{{TopicTOC-Biology}}
'''Marine biology''' is the scientific study of the biology of [[marine life]], organisms in the [[sea]]. Given that in [[biology]] many [[scientific classification|phyla]], [[family (biology)|families]] and [[genera]] have some species that live in the sea and others that live on land, marine biology classifies species based on the [[environment (biophysical)|environment]] rather than on [[taxonomy (biology)|taxonomy]].


A large proportion of all [[life|life on Earth]] lives in the ocean. The exact size of this ''large proportion'' is unknown, since many ocean species are still to be discovered. The ocean is a complex three-dimensional world<ref>[http://www.marine-conservation.org/media/shining_sea/theme_oceanography.htm Oceanographic and Bathymetric Features] ''Marine Conservation Institute''. Uploaded 18 September 2013.</ref> covering approximately 71% of the Earth's surface. The habitats studied in marine biology include everything from the tiny layers of surface water in which organisms and abiotic items may be trapped in [[surface tension]] between the ocean and atmosphere, to the depths of the [[oceanic trench]]es, sometimes 10,000 meters or more beneath the surface of the ocean. Specific habitats include [[estuaries]], [[coral reef]]s, [[kelp forest]]s, [[seagrass meadows]], the surrounds of [[seamount]]s and [[thermal vent]]s, [[tidepool]]s, muddy, sandy and rocky bottoms, and the open ocean ([[pelagic]]) zone, where solid objects are rare and the surface of the water is the only visible boundary. The organisms studied range from microscopic [[phytoplankton]] and [[zooplankton]] to huge [[cetaceans]] (whales) {{convert|25-32|m|ft|abbr=off|sp=us}} in length. [[Marine ecosystem|Marine ecology]] is the study of how marine organisms interact with each other and the environment.
Marine life is a vast resource, providing [[food]], [[medicine]], and raw materials, in addition to helping to support [[recreation]] and [[tourism]] all over the world. At a fundamental level, marine life helps determine the very nature of our planet. Marine organisms contribute significantly to the [[oxygen]] cycle, and are involved in the regulation of the earth's [[climate]].<ref name = DMS>{{cite journal
| tournal = Climatic Change
| title = Planktonic dimethylsulfide and cloud albedo: An estimate of the feedback response
| volume = 18
| year = 1991
| issue= 1
| pages = 1–15
| author = Jonathan A. Foley
| coauthors = Karl E. Taylor, Steven J. Ghan
| doi = 10.1007/BF00142502
| url = http://www.springerlink.com/content/hm3h1q666x206h46
| journal = Climatic Change
}}</ref> [[Shoreline]]s are in part shaped and protected by marine life, and some marine organisms even help create new land.<ref name=Sousa>{{cite book
| last = Sousa
| first = Wayne P
| others = eds. Steward T. A. Pickett & P. S. White
| title = The Ecology of Natural Disturbance and Patch Dynamics
| origyear = 1985
| publisher = Academic Press
| isbn = 0125545215
| chapter = 7, Disturbance and Patch Dynamics on Rocky Intertidal Shores
| chapterurl = http://books.google.co.uk/books?hl=en&lr=&id=jIj-qAflWxQC&oi=fnd&pg=PA101&dq=patch+dynamics+shoreline&ots=A3N1dTGrzY&sig=pYTEgphmnY3leFv_KU-_yAYSOy8
}}</ref>


Marine life is a vast resource, providing food, medicine, and raw materials, in addition to helping to support [[recreation]] and [[tourism]] all over the world. At a fundamental level, marine life helps determine the very nature of our planet. Marine organisms contribute significantly to the [[oxygen cycle]], and are involved in the regulation of the Earth's [[climate]].<ref name="DMS">{{cite journal | title=Planktonic dimethylsulfide and cloud albedo: An estimate of the feedback response| last1=Foley| first1=Jonathan A.| last2=Taylor| first2=Karl E.| last3=Ghan| first3=Steven J.| doi=10.1007/BF00142502| journal=Climatic Change| volume=18| issue=1| year=1991| pages=1| bibcode=1991ClCh...18....1F| s2cid=154990993}}</ref> [[Shore]]lines are in part shaped and protected by marine life, and some marine organisms even help create new land.<ref name="Sousa">{{cite book| last=Sousa| first=Wayne P.| editor1-last=Pickett| editor1-first=Steward T. A.| editor2-last=White| editor2-first=P. S.| title=The Ecology of Natural Disturbance and Patch Dynamics| orig-year=1985| publisher=Academic Press| isbn=978-0-12-554521-1| chapter=7, Disturbance and Patch Dynamics on Rocky Intertidal Shores| chapter-url=https://books.google.com/books?id=jIj-qAflWxQC&q=patch+dynamics+shoreline&pg=PA101| year=1986| url-access=registration| url=https://archive.org/details/ecologyofnatural0000pick}}</ref>
Marine biology covers a great deal, from the microscopic, including most [[zooplankton]] and [[phytoplankton]], where zooplankton can be as small as 0.02 [[micrometre|micrometers]] or as big as 2 [[meters|meters]] in the case of the [[Ocean sunfish|sunfish]] to the huge [[cetaceans]] (whales) which reach up to a reported 48 [[meters]] (125 [[foot (unit of length)|feet]]) in length.


Many species are economically important to humans, including both finfish and shellfish. It is also becoming understood that the well-being of marine organisms and other organisms are linked in fundamental ways. The human body of knowledge regarding the relationship between life in the sea and important cycles is rapidly growing, with new discoveries being made nearly every day. These cycles include those of matter (such as the [[carbon cycle]]) and of air (such as [[Global climate model|Earth's respiration]], and movement of energy through [[ecosystem]]s including the ocean). Large areas beneath the ocean surface still remain effectively unexplored.
The habitats studied by marine biology include everything from the tiny layers of surface water in which organisms and abiotic items may be trapped in [[surface tension]] between the ocean and atmosphere, to the depths of the [[Ocean trench|abyssal trenches]], sometimes 10,000 meters or more beneath the surface of the ocean. It studies habitats such as [[coral reef]]s, [[kelp forest]]s, [[tidepools]], muddy, sandy and rocky bottoms, and the open ocean (pelagic) zone, where solid objects are rare and the surface of the water is the only visible boundary.


== Biological oceanography ==
A large amount of all [[life on Earth]] exists in the oceans. Exactly how large the proportion is still unknown. While the oceans comprise about 71% of the Earth's surface, due to their depth they encompass about 300 times the habitable volume of the terrestrial habitats on Earth.
{{main|Biological oceanography}}
[[File:BlueMarble-2001-2002.jpg|thumb|400px|right|Marine biology studies species that live in [[marine habitat]]s. Most of the Earth's surface is covered by [[ocean]], which is the home to [[marine life]]. Oceans average nearly four kilometers in-depth and are fringed with coastlines that run for about [[Coastline paradox|360,000 kilometres]].<ref>{{cite journal |last=Charette |first=Matthew |author2=Smith, Walter H. F. |title=The volume of Earth's ocean |journal=Oceanography |year=2010 |volume=23 |issue=2 |pages=112–114 |doi=10.5670/oceanog.2010.51 |doi-access=free |hdl=1912/3862 |hdl-access=free }}</ref><ref>[https://www.cia.gov/the-world-factbook/countries/world/ World] ''The World Factbook'', CIA. Retrieved 13 January 2014.</ref>|alt=Two views of the ocean from space]]
Marine biology can be contrasted with [[biological oceanography]]. [[Marine life]] is a field of study both in marine biology and in biological oceanography. Biological oceanography is the study of how organisms affect and are affected by the [[physics]], [[chemistry]], and [[geology]] of the [[ocean|oceanographic system]]. Biological oceanography mostly focuses on the [[microorganism]]s within the ocean; looking at how they are affected by their environment and how that affects larger marine creatures and their ecosystem.<ref name="Lalli Parsons">Lalli, Carol M., and Timothy R. Parsons. "Introduction." Biological Oceanography: An Introduction. First Edition ed. Tarrytown, New York: Pergamon, 1993. 7-21. Print.</ref> Biological oceanography is similar to marine biology, but it studies ocean life from a different perspective. Biological oceanography takes a bottom up approach in terms of the food web, while marine biology studies the ocean from a top down perspective. Biological oceanography mainly focuses on the ecosystem of the ocean with an emphasis on plankton: their diversity (morphology, nutritional sources, motility, and metabolism); their productivity and how that plays a role in the global carbon cycle; and their distribution (predation and life cycle).<ref name="Lalli Parsons" /><ref>{{cite web|last=Menden-Deuer|first=Susanne|author-link1=Susanne Menden-Deuer|title=Course Info, OCG 561 Biological Oceanography|url=http://www.gso.uri.edu/ocg561/|access-date=2021-03-19|archive-date=2018-01-29|archive-url=https://web.archive.org/web/20180129094359/http://www.gso.uri.edu/ocg561/|url-status=dead}}</ref><ref>{{cite book|last=Miller|first=Charles B.|title=Biological Oceanography|author2=Patricia A. Wheeler|publisher=John Wiley & Sons|year=2012|edition=Second|location=Chinchester, West Sussex}}</ref> Biological oceanography also investigates the role of microbes in food webs, and how humans impact the ecosystems in the oceans.<ref name="Lalli Parsons" /><ref name=Mills1995>{{cite journal |doi = 10.1007/BF02368334|title = From marine ecology to biological oceanography|year = 1995|last1 = Mills|first1 = Eric L.|journal = Helgoländer Meeresuntersuchungen|volume = 49|issue = 1–4|pages = 29–44|bibcode = 1995HM.....49...29M|url = https://rdcu.be/chiJn|s2cid = 22149101|doi-access = free}}</ref>


==Marine habitats==
Many species are economically important to humans, including [[fishery|food fish]]. It is also becoming understood that the well-being of marine organisms and other organisms are linked in very fundamental ways. The human body of knowledge regarding the relationship between life in the sea and important cycles is rapidly growing. These cycles include those of matter (such as the [[carbon cycle]]) and of air (such as [[Global climate model|Earth's respiration]], and movement of energy through ecosystems). Large areas beneath the ocean surface still remain effectively unexplored.
{{ocean habitat topics|image=Callyspongia sp. (Tube sponge).jpg|caption=[[Coral reef]]s provide marine habitats for tube sponges, which in turn become marine habitats for fish}}
{{main|Marine habitats}}


Marine habitats can be divided into [[coastal]] and [[open ocean]] habitats. Coastal habitats are found in the area that extends from the [[shoreline]] to the edge of the [[continental shelf]]. Most marine life is found in coastal habitats, even though the shelf area occupies only seven percent of the total ocean area. Open ocean habitats are found in the deep ocean beyond the edge of the continental shelf. Alternatively, marine habitats can be divided into [[pelagic]] and [[demersal]] habitats. Pelagic habitats are found near the surface or in the open [[water column]], away from the bottom of the ocean and affected by [[ocean current]]s, while demersal habitats are near or on the bottom. Marine habitats can be modified by their inhabitants. Some marine organisms, like corals, kelp and sea grasses, are [[ecosystem engineer]]s which reshape the marine environment to the point where they create further habitat for other organisms.
== Subfields ==
The [[marine ecosystem]] is large, and thus there are many subfields of marine biology. Most involve studying specializations of particular species (i.e. [[phycology]], [[invertebrate zoology]] and [[ichthyology]]).


===Intertidal and near shore===
Other subfields study the physical effects of continual immersion in [[sea water]] and the ocean in general, adaptation to a salty environment, and the effects of changing various oceanic properties on marine life. A subfield of marine biology studies the relationships between oceans and ocean life, and global warming and environmental issues (such as [[carbon dioxide]] displacement).
[[File:Tide pools in santa cruz.jpg|thumb|left|Tide pools with sea stars and [[sea anemone]]]]


[[Intertidal zone]]s, the areas that are close to the shore, are constantly being exposed and covered by the ocean's [[tides]]. A huge array of life can be found within this zone. Shore habitats span from the upper intertidal zones to the area where land vegetation takes prominence. It can be underwater anywhere from daily to very infrequently. Many species here are scavengers, living off of sea life that is washed up on the shore. Many land animals also make much use of the shore and intertidal habitats. A subgroup of organisms in this habitat bores and grinds exposed rock through the process of [[bioerosion]].{{clear left}}
Recent marine [[biotechnology]] has focused largely on [[marine biomolecule]]s, especially [[protein]]s, that may have uses in medicine or engineering. Marine environments are the home to many exotic biological materials that may inspire [[Bionics|biomimetic material]]s.


=== Related fields ===
===Estuaries===
[[File:Urdaibai, Bizkaia, Euskal Herria.jpg|thumb|left|Estuaries have shifting flows of sea water and fresh water.]]
Marine biology is a branch of [[oceanography]] and is closely linked to [[biology]]. It also encompasses many ideas from [[ecology]]. [[Fisheries science]] and [[marine conservation]] can be considered partial offshoots of marine biology.

[[Estuaries]] are also near shore and influenced by the [[tides]]. An estuary is a partially enclosed coastal body of water with one or more rivers or streams flowing into it and with a free connection to the open sea.<ref name="james">{{cite book |last=Pritchard |first=D. W. |year=1967 |chapter= What is an estuary: physical viewpoint |pages=3–5 |editor-first=G. H. |editor-last=Lauf |title= Estuaries |series=A.A.A.S. Publ. |volume=83 |location=Washington, DC }}</ref> Estuaries form a transition zone between freshwater river environments and saltwater maritime environments. They are subject both to marine influences—such as tides, waves, and the influx of saline water—and to riverine influences—such as flows of fresh water and sediment. The shifting flows of both sea water and fresh water provide high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world.<ref name="McLusky">{{cite book |last1=McLusky |first1=D. S. |last2=Elliott |first2=M. |year=2004 |title=The Estuarine Ecosystem: Ecology, Threats and Management |location=New York |publisher=Oxford University Press |isbn=978-0-19-852508-0 }}</ref>{{clear left}}

=== Reefs ===
[[File:Maldivesfish2.jpg|thumb|left|[[Coral reef]]s form complex marine ecosystems with tremendous [[biodiversity]].]]
{{Main|Coral reef}}

[[Reef]]s comprise some of the densest and most diverse habitats in the world. The best-known types of reefs are [[tropical]] [[coral reef]]s which exist in most tropical waters; however, reefs can also exist in cold water. Reefs are built up by [[coral]]s and other [[calcium]]-depositing animals, usually on top of a rocky outcrop on the ocean floor. Reefs can also grow on other surfaces, which has made it possible to create [[artificial reef]]s. Coral reefs also support a huge community of life, including the corals themselves, their symbiotic [[zooxanthellae]], tropical fish and many other organisms.

Much attention in marine biology is focused on coral reefs and the [[El Niño]] weather phenomenon. In 1998, coral reefs experienced the most severe mass bleaching events on record, when vast expanses of reefs across the world died because [[sea surface temperature]]s rose well above normal.<ref>NOAA (1998) Record-breaking coral bleaching occurred in tropics this year. [[National Oceanic and Atmospheric Administration]], Press release (October 23, 1998).</ref><ref>ICRS (1998) Statement on Global Coral Bleaching in 1997-1998. International Coral Reef Society, October 15, 1998.</ref> Some reefs are recovering, but scientists say that between 50% and 70% of the world's coral reefs are now endangered and predict that [[global warming]] could exacerbate this trend.<ref>Bryant, D., Burke, L., McManus, J., et al. (1998) "Reefs at risk: a map-based indicator of threats to the world's coral reefs". World Resources Institute, Washington, D.C.</ref><ref>{{cite journal | last1=Goreau | first1=T. J. | year=1992 | title=Bleaching and Reef Community Change in Jamaica: 1951 - 1991 | journal=Am. Zool. | volume=32 | issue=6| pages=683–695 | doi=10.1093/icb/32.6.683| doi-access=free }}</ref><ref>{{cite journal | last1=Sebens | first1=K. P. | year=1994 | title=Biodiversity of Coral Reefs: What are We Losing and Why? | journal=Am. Zool. | volume=34 | pages=115–133 | doi=10.1093/icb/34.1.115| doi-access=free }}</ref><ref>Wilkinson, C. R., and Buddemeier, R. W. (1994) "Global Climate Change and Coral Reefs:Implications for People and Reefs". Report of the UNEP-IOC-ASPEI-IUCN Global Task Team on the Implications of Climate Change on Coral Reefs. IUCN, Gland, Switzerland.</ref>{{clear left}}

[[File:Representative ocean animal life.jpg|thumb|upright=1.7| Some representative ocean animal life (not drawn to scale) within their approximate depth-defined ecological habitats. [[Marine microorganisms]] exist on the surfaces and within the tissues and organs of the diverse life inhabiting the ocean, across all ocean habitats.<ref name="Apprill2017">Apprill, A. (2017)"Marine animal microbiomes: toward understanding host–microbiome interactions in a changing ocean". ''Frontiers in Marine Science'', '''4''': 222. {{doi|10.3389/fmars.2017.00222}}. [[File:CC-BY icon.svg|50px]] Material was copied from this source, which is available under a [https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International License].</ref>]]

===Open ocean===
[[File:Humpback stellwagen edit.jpg|thumb|left|The open ocean is the area of deep sea beyond the [[continental shelves]].]]
{{Main|Pelagic zone}}

The open ocean is relatively unproductive because of a lack of nutrients, yet because it is so vast, in total it produces the most primary productivity. The open ocean is separated into different zones, and the different zones each have different ecologies.<ref>{{Cite web|url=http://marinebio.org/oceans/open-ocean/|title=The Open Ocean - MarineBio.org|website=marinebio.org|access-date=2016-09-26}}</ref> Zones which vary according to their depth include the [[epipelagic]], [[mesopelagic]], [[bathypelagic]], [[abyssopelagic]], and [[hadopelagic]] zones. Zones which vary by the amount of light they receive include the [[Photic zone|photic]] and [[aphotic zone]]s. Much of the aphotic zone's energy is supplied by the open ocean in the form of [[detritus]].{{clear left}}

=== Deep sea and trenches ===
[[File:Deep sea chimaera.jpg|thumb|left| A deep-sea chimaera. Its snout is covered with tiny pores capable of detecting animals by perturbations in electric fields.]]

The deepest recorded [[oceanic trench]] measured to date is the [[Mariana Trench]], near the [[Philippines]], in the [[Pacific Ocean]] at {{convert|10,924|m|ft|abbr=on}}. At such depths, [[water pressure]] is extreme and there is no sunlight, but some life still exists. A white [[flatfish]], a shrimp and a jellyfish were seen by the American crew of the [[bathyscaphe]] ''[[Bathyscaphe Trieste|Trieste]]'' when it dove to the bottom in 1960.<ref>[http://bjsonline.com/watches/articles/0022_3.shtml Seven Miles Down: The Story of The Bathyscaph Trieste.] {{webarchive|url=https://web.archive.org/web/20070202144233/http://bjsonline.com/watches/articles/0022_3.shtml |date=2007-02-02 }}, ''Rolex Deep Sea Special'', January 2006.</ref> In general, the deep sea is considered to start at the [[aphotic zone]], the point where sunlight loses its power of transference through the water.<ref>{{Cite web|url=https://www.encyclopedia.com/earth-and-environment/geology-and-oceanography/geology-and-oceanography/aphotic-zone|title=Aphotic Zone {{!}} Encyclopedia.com|website=www.encyclopedia.com|access-date=2018-12-06}}</ref> Many life forms that live at these depths have the ability to create their own light known as [[bio-luminescence]]. Marine life also flourishes around [[seamount]]s that rise from the depths, where fish and other sea life congregate to spawn and feed. [[Hydrothermal vent]]s along the [[mid-ocean ridge]] spreading centers act as [[oasis|oases]], as do their opposites, [[cold seeps]]. Such places support unique [[biome]]s and many new [[microbe]]s and other lifeforms have been discovered at these locations.<ref>{{Cite book|url=https://books.google.com/books?id=nAAtDwAAQBAJ&q=%22Deep-Sea+Fishes%22|title=Deep-Sea Fishes: Biology, Diversity, Ecology and Fisheries|isbn=9781107083820|last1=Priede|first1=Imants G.|pages = 12–13 |date=10 August 2017|publisher=Cambridge University Press }}</ref>

{{clear}}

== Marine life ==
{{main article|Marine life}}
{{marine life sidebar}}

{{multiple image
| align = right
| caption_align = center
| direction = vertical
| width = 260
| image1 = Copepodkils.jpg
| caption1 = [[Copepod]]
| image2 = Crown of Thorns-jonhanson.jpg
| caption2 = [[Crown-of-thorns starfish]]
| image3 = Grilse001.jpg
| caption3 = Mature salmon with fungal disease
| image4 = Chelonia mydas and bubbles.jpg
| caption4 = [[Green turtle]]
| image5 = Black-browed albatross.jpg|
| caption5 = [[Albatross]] hovering over the ocean looking for prey
| image6 = Sea otters holding hands, cropped.jpg
| caption6 = [[Sea otter]]s
}}

In biology many phyla, families and genera have some species that live in the sea and others that live on land. Marine biology classifies species based on the environment rather than on taxonomy. For this reason marine biology encompasses not only organisms that live only in a marine environment, but also other organisms whose lives revolve around the sea.


== Lifeforms ==
=== Microscopic life ===
=== Microscopic life ===
{{main article|Marine microorganism}}
[[Image:Copepodkils.jpg|thumb|right|A [[copepod]].]]

Microscopic life undersea is incredibly diverse and still poorly understood. For example, the role of [[virus]]es in marine ecosystems is barely being explored even in the beginning of the 21st century.
As inhabitants of the largest environment on Earth, microbial marine systems drive changes in every global system. Microbes are responsible for virtually all the [[photosynthesis]] that occurs in the ocean, as well as the cycling of [[carbon]], [[nitrogen]], [[phosphorus]] and other [[nutrients]] and trace elements.<ref>{{cite web |url=https://www.sciencedaily.com/releases/2015/12/151210181647.htm |title=Functions of global ocean microbiome key to understanding environmental changes |date=December 10, 2015 |website=www.sciencedaily.com |publisher=University of Georgia |access-date=December 11, 2015}}</ref>

Microscopic life undersea is incredibly diverse and still poorly understood. For example, the role of [[virus]]es in marine ecosystems is barely being explored even in the beginning of the 21st century.<ref>{{cite journal|last=Suttle
|first=C.A.|title=Viruses in the Sea|journal=Nature|year=2005|volume=437|issue=9|pages=356–361|doi=10.1038/nature04160|pmid=16163346|bibcode=2005Natur.437..356S|s2cid=4370363}}</ref>


The role of [[phytoplankton]] is better understood due to their critical position as the most numerous [[primary production|primary producers]] on Earth. Phytoplankton are categorized into [[cyanobacteria]] (also called blue-green algae/bacteria), various types of [[algae]] (red, green, brown, and yellow-green), [[diatom]]s, [[dinoflagellate]]s, [[Euglenid|euglenoids]], [[coccolithophorid]]s, [[cryptomonad]]s, [[chrysophyte]]s, [[chlorophyte]]s, [[prasinophyte]]s, and [[silicoflagellate]]s.
The role of [[phytoplankton]] is better understood due to their critical position as the most numerous [[primary production|primary producers]] on Earth. Phytoplankton are categorized into [[cyanobacteria]] (also called blue-green algae/bacteria), various types of [[algae]] (red, green, brown, and yellow-green), [[diatom]]s, [[dinoflagellate]]s, [[Euglenid|euglenoids]], [[coccolithophorid]]s, [[cryptomonad]]s, [[chrysophyte]]s, [[chlorophyte]]s, [[prasinophyte]]s, and [[silicoflagellate]]s.


[[Zooplankton]] tend to be somewhat larger, and not all are microscopic. Many [[Protozoa]] are zooplankton, including dinoflagellates, [[zooflagellate]]s, [[foraminifera]]ns, and [[radiolarian]]s. Some of these (such as dinoflaggelates) are also phytoplankton; the [[plant/animal distinction]] often breaks down in very small organisms. Other zooplankton include [[cnidarian]]s, [[ctenophore]]s, [[chaetognatha|chaetognaths]], [[mollusc]]s, [[arthropod]]s, [[Tunicate|urochordates]], and [[annelid]]s such as [[polychaete]]s. Many larger animals begin their life as zooplankton before they become large enough to take their familiar forms. Two examples are fish [[larva]]e and sea stars (also called [[starfish]]).
[[Zooplankton]] tend to be somewhat larger, and not all are microscopic. Many [[Protozoa]] are zooplankton, including dinoflagellates, [[zooflagellate]]s, [[foraminifera]]ns, and [[radiolarian]]s. Some of these (such as dinoflagellates) are also phytoplankton; the distinction between plants and animals often breaks down in very small organisms. Other zooplankton include [[cnidarian]]s, [[Ctenophora (phylum)|ctenophore]]s, [[chaetognatha|chaetognaths]], [[mollusc]]s, [[arthropod]]s, [[Tunicate|urochordates]], and [[annelid]]s such as [[polychaete]]s. Many larger animals begin their life as zooplankton before they become large enough to take their familiar forms. Two examples are [[fish larva]]e and sea stars (also called [[starfish]]).


[[Image:Giantkelp2 300.jpg|thumb|right|Giant [[kelp]].]]
=== Plants and algae ===
=== Plants and algae ===
{{main article|Marine algae and plants}}
Plant life is relatively rare undersea. Most of the [[ecological niche|niche]] occupied by sub plants on land is actually occupied by macroscopic [[algae]] in the ocean, such as ''[[Sargassum]]'' and [[kelp]], which are commonly known as [[seaweed]]s that create [[kelp forest]]s. The non algae plants that do survive in the sea are often found in shallow waters, such as the [[seagrass]]es (examples of which are eelgrass, ''[[Zostera]]'', and turtle grass, ''Thalassia''). These plants have adapted to the high salinity of the ocean environment. The [[foreshore|intertidal zone]] is also a good place to find plant life in the sea, where [[mangroves]] or [[cordgrass]] or [[Ammophila (Poaceae)|beach grass]] might grow. Sea [[kelp]] is very important to small sea creatures because the creatures can hide from predators. Eel grass is the most important. It is where hairing and other small fish live to escape from preditors.


Microscopic algae and plants provide important habitats for life, sometimes acting as hiding places for larval forms of larger fish and foraging places for invertebrates.
[[Image:Crown of Thorns-jonhanson.jpg|thumb|right|A [[crown-of-thorns starfish]].'']]


Algal life is widespread and very diverse under the ocean. Microscopic photosynthetic algae contribute a larger proportion of the world's photosynthetic output than all the terrestrial forests combined. Most of the [[ecological niche|niche]] occupied by sub plants on land is actually occupied by macroscopic [[algae]] in the ocean, such as ''[[Sargassum]]'' and [[kelp]], which are commonly known as [[seaweed]]s that create [[kelp forest]]s.
===Marine invertebrates ===
{{Main|Marine invertebrates}}
As on land, [[invertebrates]] make up a huge portion of all life in the sea. Invertebrate sea life includes [[Cnidaria]] such as [[jellyfish]] and [[sea anemone]]s; [[Ctenophora]]; [[sea worm]]s including the [[phylum (biology)|phyla]] [[Platyhelminthes]], [[Nemertea]], [[Annelida]], [[Sipuncula]], [[Echiura]], [[Chaetognatha]], and the [[Phoronida]]; [[Mollusca]] including [[shellfish]], [[squid]], [[octopus]]; [[Crustacea]]; [[Porifera]]; [[Bryozoa]]; [[Echinodermata]] including starfish; and [[Urochordete]] - [[sea squirt]]s or [[tunicate]]s.


Plants that survive in the sea are often found in shallow waters, such as the [[seagrass]]es (examples of which are eelgrass, ''[[Zostera]]'', and turtle grass, ''Thalassia''). These plants have adapted to the high salinity of the ocean environment. The [[foreshore|intertidal zone]] is also a good place to find plant life in the sea, where [[mangroves]] or [[cordgrass]] or [[Ammophila (Poaceae)|beach grass]] might grow.
[[Image:Carcharhinus longimanus 1.jpg|thumb|right|[[Oceanic whitetip shark|Whitetip shark]] with [[pilot fish]].]]


=== Fish ===
===Invertebrates===
{{Main|Marine invertebrates}}
{{main | Fish}}
Fish have [[evolution|evolved]] very different biological functions from other large organisms. Fish anatomy includes a two-chambered heart, [[Operculum (Fish)|operculum]], secretory [[cell (biology)|cells]] that produce [[mucous]], [[swim bladder]], [[scale (zoology)|scales]], [[fin]]s, [[lip]]s and [[eye]]s. Fish breathe by extracting oxygen from water through their gills. Fins propel and stabilize the fish in the water.


As on land, [[invertebrates]] make up a huge portion of all life in the sea. Invertebrate sea life includes [[Cnidaria]] such as [[jellyfish]] and [[sea anemone]]s; [[Ctenophora (phylum)|Ctenophora]]; [[sea worm]]s including the [[phylum (biology)|phyla]] [[Platyhelminthes]], [[Nemertea]], [[Annelida]], [[Sipuncula]], [[Echiura]], [[Chaetognatha]], and [[Phoronida]]; [[Mollusca]] including [[shellfish]], [[squid]], [[octopus]]; [[Arthropoda]] including [[Chelicerata]] and [[Crustacea]]; [[Porifera]]; [[Bryozoa]]; [[Echinodermata]] including starfish; and [[Urochordata]] including [[sea squirt]]s or [[tunicate]]s. Invertebrates have no backbone. There are over a million species.
Well known fish include: [[sardine]]s, [[anchovy]], [[ling cod]], [[clownfish]] (also known as anemonefish), and [[Bottom feeder|bottom fish]] which include [[halibut]] or [[ling cod]]. [[Predator]]s include [[shark]]s and [[barracuda]].


=== Fungi ===
[[Image:Sea turtle small.jpg|thumb|right|[[Sea turtle]].]]
{{main|Marine fungi}}


Over 10,000<ref>{{Cite journal|last1=Amend|first1=Anthony|last2=Burgaud|first2=Gaetan|last3=Cunliffe|first3=Michael|last4=Edgcomb|first4=Virginia P.|last5=Ettinger|first5=Cassandra L.|last6=Gutiérrez|first6=M. H.|last7=Heitman|first7=Joseph|last8=Hom|first8=Erik F. Y.|last9=Ianiri|first9=Giuseppe|last10=Jones|first10=Adam C.|last11=Kagami|first11=Maiko|date=2019-03-05|title=Fungi in the Marine Environment: Open Questions and Unsolved Problems|journal=mBio|volume=10|issue=2|language=EN|doi=10.1128/mBio.01189-18|pmid=30837337|pmc=6401481|s2cid=73481006}}{{Dead link|date=October 2022 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> species of [[fungi]] are known from marine environments.<ref>{{cite journal|last=Hyde|first=K.D. |author2=E.B.J. Jones |author3=E. Leaño |author4=S.B. Pointing |author5=A.D. Poonyth |author6=L.L.P. Vrijmoed|title=Role of fungi in marine ecosystems|journal=Biodiversity and Conservation|year=1998|volume=7|issue=9|pages=1147–1161|doi=10.1023/A:1008823515157|s2cid=22264931 }}</ref> These are parasitic on [[marine algae]] or animals, or are [[saprobe]]s on algae, corals, protozoan cysts, sea grasses, wood and other substrata, and can also be found in [[sea foam]].<ref>Kirk, P.M., Cannon, P.F., Minter, D.W. and Stalpers, J. "Dictionary of the Fungi". Edn 10. CABI, 2008</ref> Spores of many species have special appendages which facilitate attachment to the substratum.<ref>{{cite journal|last=Hyde|first=K.D.|author2=E.B.J. Jones|title=Spore attachment in marine fungi|journal=Botanica Marina|year=1989|volume=32|issue=3|pages=205–218|doi=10.1515/botm.1989.32.3.205|s2cid=84879817}}</ref> A very diverse range of unusual secondary [[metabolite]]s is produced by marine fungi.<ref>{{cite journal|last=San-Martín|first=A. |author2=S. Orejanera |author3=C. Gallardo |author4=M. Silva |author5=J. Becerra |author6=R. Reinoso |author7=M.C. Chamy |author8=K. Vergara |author9=J. Rovirosa|title=Steroids from the marine fungus Geotrichum sp|journal=Journal of the Chilean Chemical Society|year=2008|volume=53|issue=1|pages=1377–1378|doi=10.4067/S0717-97072008000100011 |doi-access=free }}</ref>
=== Reptiles ===
{{main|Marine reptile}}
[[Reptile]]s which inhabit or frequent the sea include [[sea turtle]]s, [[Marine Iguana]], [[sea snake]]s, and [[Saltwater Crocodile]]s. Most [[extant taxon|extant]] marine reptiles, except for some sea snakes are [[oviparity|oviparous]] and need to return to land to lay their eggs. Thus most species, excepting sea turtles, live on or near land rather than in the ocean. Some [[extinction|extinct]] marine reptiles, such as [[ichthyosaur]]s, evolved to be [[viviparity|viviparous]] and had no requirement to return to land.


===Vertebrates===
[[Image:Penguinu.jpg|thumb|right|[[Chinstrap penguin]].]]
{{main article|Marine vertebrates}}


=== Seabirds ===
==== Fish ====
{{main article|Fish}}
[[Seabird]]s are species of [[bird]]s adapted to living in the marine environment, examples including [[albatross]], [[penguin]]s, [[gannet]]s, and [[auk]]s. Although they spend most of their lives in the ocean, species such as [[gull]]s can often be found thousands of miles inland.


A reported [[Diversity of fish|33,400 species of fish]], including [[bony fish|bony]] and [[cartilaginous fish]], had been described by 2016,<ref>{{cite web |url=http://www.fishbase.org |title=Fishbase |access-date=6 February 2017}}</ref> more than all other vertebrates combined. About 60% of fish species live in saltwater.<ref>{{cite book |author=Moyle, P. B.; Leidy, R. A. |date=1992 |title=Loss of biodiversity in aquatic ecosystems: Evidence from fish faunas |pages=128–169 |editor=Fiedler, P. L.; Jain, S. A. Jain |work=Conservation Biology: the theory and practice of nature conservation, preservation, and management |publisher=Chapman and Hall}}</ref>
[[Image:Sea otters holding hands.jpg|thumb|right|[[Sea otter]]s.]]
=== Marine mammals ===
{{main | Marine mammal}}
There are five main types of marine mammals.
* [[Cetacea]]ns include [[toothed whale]]s (Suborder [[Odontoceti]]), such as the [[Sperm Whale]], [[dolphin]]s, and [[porpoise]]s such as the [[Dall's porpoise]]. Cetaceans also include [[baleen whale]]s (Suborder [[Mysticeti]]), such as the [[Gray Whale]], [[Humpback Whale]], and [[Blue Whale]].
* [[Sirenian]]s include [[manatee]]s, the [[Dugong]], and the extinct [[Steller's Sea Cow]].
* [[Pinniped|Seal]]s (Family [[Phocidae]]), [[sea lion]]s (Family [[Otariidae]] - which also include the fur seals), and the [[Walrus]] (Family [[Odobenidae]]) are all considered [[pinniped]]s.
* The [[Sea Otter]] is a member of the Family [[Mustelidae]], which includes [[weasel]]s and [[badger]]s.
* Finally, the [[Polar Bear]] (Family [[Ursidae]]) is sometimes considered a marine mammal because of its dependence on the sea.


==Oceanic habitats==
==== Reptiles ====
{{Main|Marine reptile}}
{{ocean habitat topics}}
=== Reefs ===
{{main | Coral reef}}
[[Image:Coral reefs in papua new guinea.JPG|thumb|200px|left|[[Coral]]s reefs in [[Papua New Guinea]].]]
[[Reef]]s comprise some of the densest and most diverse habitats in the world. The best-known types of reefs are [[tropical]] [[coral reef]]s which exist in most tropical waters; however, reefs can also exist in cold water. Reefs are built up by [[coral]]s and other [[calcium]]-depositing animals, usually on top of a rocky outcrop on the ocean floor. Reefs can also grow on other surfaces, which has made it possible to create [[artificial reef]]s. Coral reefs also support a huge community of life, including the corals themselves, their symbiotic [[zooxanthellae]], tropical fish and many other organisms.


[[Reptile]]s which inhabit or frequent the sea include [[sea turtle]]s, [[sea snake]]s, [[terrapin]]s, the [[marine iguana]], and the [[saltwater crocodile]]. Most [[extant taxon|extant]] marine reptiles, except for some sea snakes, are [[oviparity|oviparous]] and need to return to land to lay their eggs. Thus most species, excepting sea turtles, spend most of their lives on or near land rather than in the ocean. Despite their marine adaptations, most sea snakes prefer shallow waters nearby land, around islands, especially waters that are somewhat sheltered, as well as near estuaries.<ref name="Sti74">Stidworthy J. 1974. Snakes of the World. Grosset & Dunlap Inc. 160 pp. {{ISBN|0-448-11856-4}}.</ref><ref name="RAS-FAO">[ftp://ftp.fao.org/docrep/fao/009/y0870e/y0870e65.pdf Sea snakes]{{dead link|date=January 2018 |bot=InternetArchiveBot |fix-attempted=yes }} at [http://www.fao.org/ Food and Agriculture Organization of the United Nations]. Accessed 7 August 2007.</ref> Some [[extinction|extinct]] marine reptiles, such as [[ichthyosaur]]s, evolved to be [[viviparity|viviparous]] and had no requirement to return to land.
Much attention in marine biology is focused on coral reefs and the [[El Niño]] weather phenomenon. In 1998, coral reefs experienced a "once in a thousand years" bleaching event, in which vast expanses of reefs across the Earth died because sea surface temperatures rose well above normal. Some reefs are recovering, but scientists say that 58[[%]] of the world's coral reefs are now endangered and predict that [[global warming]] could exacerbate this trend.


=== Deep sea and trenches ===
==== Birds ====
{{Main|Seabird}}
The deepest recorded [[oceanic trench]]es measure to date is the [[Mariana Trench]], near the [[Philippines]], in the [[Pacific Ocean]] at 10924 m (35838 ft). At such depths, [[water pressure]] is extreme and there is no sunlight, but some life still exists. Small flounder (family [[Soleidae]]) fish and shrimp were seen by the American crew of the [[bathyscaphe]] ''[[Bathyscaphe Trieste|Trieste]]'' when it dove to the bottom in 1960.


Birds adapted to living in the [[marine environment]] are often called [[seabird]]s. Examples include [[albatross]], [[penguin]]s, [[gannet]]s, and [[auk]]s. Although they spend most of their lives in the ocean, species such as [[gull]]s can often be found thousands of miles inland.
Other notable oceanic trenches include [[Monterey Canyon]], in the eastern Pacific, the [[Tonga Trench]] in the southwest at 10,882 m (35,702 ft), the [[Philippine Trench]], the [[Puerto Rico Trench]] at 8605 m (28232 ft), the [[Romanche Trench]] at 7760 m (24450 ft), [[Fram Basin]] in the [[Arctic Ocean]] at 4665 m (15305 ft), the [[Java Trench]] at 7450 m (24442 ft), and the [[South Sandwich Trench]] at 7235 m (23737 ft).


==== Mammals ====
In general, the deep sea is considered to start at the [[aphotic zone]], the point where sunlight loses its power of transference through the water. Many life forms that live at these depths have the ability to create their own light.
{{Main|Marine mammal}}


There are five main types of marine mammals, namely [[cetacea]]ns ([[toothed whale]]s and [[baleen whale]]s); [[sirenian]]s such as [[manatee]]s; [[pinniped]]s including seals and the [[walrus]]; [[sea otter]]s; and the
Much life centers on [[seamount]]s that rise from the deeps, where fish and other sea life congregate to spawn and feed. [[Hydrothermal vent]]s along the [[mid-ocean ridge]] spreading centers act as [[oasis|oases]], as do their opposites, [[cold seeps]]. Such places support unique [[biome]]s and many new [[microbe]]s and other lifeforms have been discovered at these locations.
[[polar bear]]. All are air-breathing, and while some such as the [[sperm whale]] can dive for prolonged periods, all must return to the surface to breathe.<ref>{{Cite journal | doi=10.1371/journal.pone.0019653| pmid=21625431| title=Current and Future Patterns of Global Marine Mammal Biodiversity| journal=PLOS ONE| volume=6| issue=5| pages=e19653| year=2011| last1=Kaschner | first1=K. | last2=Tittensor | first2=D. P. | last3=Ready | first3=J. | last4=Gerrodette | first4=T. | last5=Worm | first5=B. | bibcode=2011PLoSO...619653K| pmc=3100303| doi-access=free}}</ref><ref>{{Cite journal | last1=Pompa | first1=S. | last2=Ehrlich | first2=P. R. | last3=Ceballos | first3=G. | doi=10.1073/pnas.1101525108 | pmid=21808012 | title=Global distribution and conservation of marine mammals | journal=Proceedings of the National Academy of Sciences| volume=108 | issue=33 | pages=13600–13605| date=2011-08-16 | bibcode=2011PNAS..10813600P | pmc=3158205 | doi-access=free }}</ref>


{{clear}}
===Open ocean===
The great expanse of open ocean habitat is huge, and many species can be found passing through it and living in it. The term "open ocean" usually is meant to refer to the vast stretches of water between points of land, or between undersea mounts. Contrary to popular notions the open ocean is often not the place where marine animals spend the majority of their lives. Most species simply pass through the open ocean on their ways to other places. Larger species are the main ongoing inhabitants.


== Subfields ==
===Intertidal and shore===
The [[marine ecosystem]] is large, and thus there are many sub-fields of marine biology. Most involve studying specializations of particular animal groups, such as [[phycology]], [[invertebrate zoology]] and [[ichthyology]]. Other subfields study the physical effects of continual immersion in [[sea water]] and the ocean in general, adaptation to a salty environment, and the effects of changing various oceanic properties on marine life. A subfield of marine biology studies the relationships between oceans and ocean life, and global warming and environmental issues (such as [[carbon dioxide]] displacement). Recent marine [[biotechnology]] has focused largely on marine [[biomolecule]]s, especially [[protein]]s, that may have uses in medicine or engineering. Marine environments are the home to many exotic biological materials that may inspire [[Bionics|biomimetic material]]s.
[[Image:Tide pools in santa cruz.jpg|200px|thumb|Tide pools with sea stars and [[sea anemone]] in Santa Cruz,[[California]]]][[Intertidal zone]]s, those areas close to shore, are constantly being exposed and covered by the ocean's [[tides]]. A huge array of life lives within this zone.


Through constant monitoring of the ocean, there have been discoveries of marine life which could be used to create remedies for certain diseases such as cancer and leukemia. In addition, Ziconotide, an approved drug used to treat pain, was created from a snail which resides in the ocean.<ref>{{cite journal |last1=Malve |first1=Harshad |title=Exploring the ocean for new drug developments: Marine pharmacology |journal=Journal of Pharmacy & Bioallied Sciences |date=2016 |volume=8 |issue=2 |pages=83–91 |doi=10.4103/0975-7406.171700 |pmid=27134458 |pmc=4832911 |doi-access=free }}</ref>
Shore habitats span from the upper intertidal zones to the area where land vegetation takes prominence. It can be underwater anywhere from daily to very infrequently. Many species here are scavengers, living off of sea life that is washed up on the shore. Many land animals also make much use of the shore and intertidal habitats. A subgroup of organisms in this habitat bores and grinds exposed rock through the process of [[bioerosion]].

=== Related fields ===
Marine biology is a branch of [[biology]]. It is closely linked to [[oceanography]], especially [[biological oceanography]], and may be regarded as a sub-field of [[marine science]]. It also encompasses many ideas from [[ecology]]. [[Fisheries science]] and [[marine conservation]] can be considered partial offshoots of marine biology (as well as [[environmental studies]]). Marine Chemistry, Physical oceanography and Atmospheric sciences are closely related to this field.


==Distribution factors==
==Distribution factors==
An active research topic in marine biology is to discover and map the [[biological life cycle|life cycle]]s of various species and where they spend their time. Marine biologists study how the [[ocean current]]s, [[tide]]s and many other oceanic factors affect ocean lifeforms, including their growth, distribution and well-being. This has only recently become technically feasible with advances in [[Global Positioning System|GPS]] and newer underwater visual devices.
An active research topic in marine biology is to discover and map the [[biological life cycle|life cycle]]s of various species and where they spend their time. Technologies that aid in this discovery include [[pop-up satellite archival tag]]s, [[acoustic tag]]s, and a variety of other [[data loggers]]. Marine biologists study how the [[ocean current]]s, [[tide]]s and many other oceanic factors affect ocean life forms, including their growth, distribution and well-being. This has only recently become technically feasible with advances in [[Global Positioning System|GPS]] and newer underwater visual devices.<ref>{{Cite journal |last1=Hulbert |first1=Ian A.R. |last2=French |first2=John |date=21 December 2001 |title=The accuracy of GPS for wildlife telemetry and habitat mapping: GPS for telemetry and mapping |journal=Journal of Applied Ecology |language=en |volume=38 |issue=4 |pages=869–878 |doi=10.1046/j.1365-2664.2001.00624.x|doi-access=free }}</ref>


Most ocean life breeds in specific places, nests or not in others, spends time as juveniles in still others, and in maturity in yet others. Scientists know little about where many species spent different parts of their life cycles. For example, it is still largely unknown where [[sea turtle]]s travel. Tracking devices do not work for some life forms, and the ocean is not friendly to [[technology]].
Most ocean life breeds in specific places, nests or not in others, spends time as juveniles in still others, and in maturity in yet others. Scientists know little about where many species spend different parts of their life cycles especially in the infant and juvenile years. For example, it is still largely unknown where juvenile [[sea turtle]]s and some year-1 [[shark]]s travel. Recent advances in underwater tracking devices are illuminating what we know about marine organisms that live at great Ocean depths.<ref>{{Cite web | url=http://us7.campaign-archive2.com/?u=82eb97f4b587306a3537ecf16&id=e398851e6b&e=%5BUNIQID%5D | title=March 2014 Newsletter - What's Going on at Desert Star}}</ref> The information that [[pop-up satellite archival tag]]s give aids in certain time of the year fishing closures and development of a [[marine protected area]]. This data is important to both scientists and fishermen because they are discovering that by restricting commercial fishing in one small area they can have a large impact in maintaining a healthy fish population in a much larger area.


== History ==
== Famous marine biologists ==
{{main|History of marine biology}}
[[Image:Jacques-Yves Cousteau.jpg|right|thumb|Jacques-Yves Cousteau, co-inventor of the [[aqua-lung]], is well known for popularizing marine biology.]]
[[File:Scyliorhinus retifer embryo.JPG|thumb|left|[[Aristotle's biology|Aristotle]] recorded that the [[embryo]] of [[Mustelus canis|<!--a different species shown-->a dogfish]] was attached by a cord to a kind of placenta (the [[yolk sac]]).<ref>{{cite book|author=Leroi, Armand Marie|title=The Lagoon: How Aristotle Invented Science|title-link=Aristotle's Lagoon|date=2014|publisher=Bloomsbury|isbn=978-1-4088-3622-4|pages=72–74|author-link=Armand Marie Leroi}}</ref>]]
* [[Ali Abdelghany]] (born 1944), [[Egypt]]ian marine biologist
* [[Adolf Appellöf|Jakob Johan Adolf Appellöf]] (1857-1921), [[Sweden|Swedish]] marine zoologist.
* [[Samuel Stillman Berry]] (1887-1984), U.S. marine zoologist.
* [[Henry Bryant Bigelow]] (1879–1967), U.S. marine biologist.
* [[Rachel Carson]] (1907-1964), American Marine Biologist and Author.
* [[Carl Chun]] (1852-1914), [[Germany|German]] marine biologist
* [[Jacques-Yves Cousteau]] (1910-1997), [[France|French]] marine biologist and explorer
* [[Charles Darwin]] (1809-1882), wrote ''Structure and Distribution of Coral Reefs'' (1842) while aboard the [[HMS Beagle]]
*[[ Paul K. Dayton]] (born 1941), American benthic marine ecologist noted for work in [[kelp forest]] [[ecology]]
* [[Anton Dohrn]] (1840-1909), German marine biologist
* [[Sylvia Earle]] (born 1935), American oceanographer
* [[Ernst Haeckel]] (1834–1919), German physician, zoologist, marine biologist and evolutionist
* [[Hans Hass]] (born 1919), Austrian marine biologist and diving pioneer
* [[Gotthilf Hempel]] (born 1929), German marine biologist
* [[Johan Hjort]] (1869-1948), Norwegian marine zoologist and one of the founders of [[ICES]]
* [[Bruno Hofer]] (1861-1916), German fisheries scientist
* [[Hirohito|Emperor Showa of Japan]] (1901-1989), [[jellyfish]] [[taxonomy|taxonomist]]
* [[Uwe Kils]] (born 1951), German marine biologist
* [[August David Krohn]] (1803–1891), Russian/German zoologist
* [[William Elford Leach]] (1790-1836), [[England|English]] zoologist and marine biologist
* [[Nicholai Miklukho-Maklai]] (1846-1888), [[Russia]]n marine biologist and anthropologist
* [[John Murray (oceanographer)|Sir John Murray]] (1841-1914), [[Scotland|Scots]]-[[Canada|Canadian]] marine biologist
* [[Ed Ricketts]] (1897-1948), American marine biologist noted for a pioneering study of intertidal ecology
* [[Harald Rosenthal]] (born 1937), German hydrobiologist known for his work in fish farming and ecology
* [[Michael Sars]] (1809–1869), [[Norway|Norwegian]] theologian and biologist
* [[Georg Sars]] (1837-1927), Norwegian marine biologist
* [[Gunnar Thorson]] (1906-1971), Danish marine biologist
* [[Ruth Turner]] (1915-2000), marine biologist
* [[Charles Wyville Thompson]] (1832-1882), Scottish marine biologist


The study of marine biology dates to [[Aristotle]] (384–322 BC), who made [[Aristotle's biology#Empirical research|many observations of life in the sea]] around [[Lesbos]], laying the foundation for many future discoveries.<ref>"History of the Study of Marine Biology - MarineBio.org". MarineBio Conservation Society. Web. Monday, March 31, 2014. <http://marinebio.org/oceans/history-of-marine-biology.asp {{Webarchive|url=https://wayback.archive-it.org/all/20140303174702/http://www.marinebio.org/oceans/history-of-marine-biology.asp|date=2014-03-03}}></ref> In 1768, [[Samuel Gottlieb Gmelin]] (1744–1774) published the ''Historia Fucorum'', the first work dedicated to marine [[algae]] and the first book on marine biology to use the new [[binomial nomenclature]] of [[Carl Linnaeus|Linnaeus]]. It included elaborate illustrations of seaweed and marine algae on folded leaves.<ref>Gmelin S G (1768) [https://books.google.com/books?id=YUAAAAAAQAAJ&q=%22Historia+Fucorum%22 ''Historia Fucorum''] Ex typographia Academiae scientiarum, St. Petersburg.</ref><ref>Silva PC, Basson PW and Moe RL (1996) [https://books.google.com/books?id=vuWEemVY8WEC&dq=%22Historia+Fucorum%22+binomial+nomenclature&pg=PA2 ''Catalogue of the Benthic Marine Algae of the Indian Ocean''] page 2, University of California Press. {{ISBN|9780520915817}}.</ref> The British naturalist [[Edward Forbes]] (1815–1854) is generally regarded as the founder of the science of marine biology.<ref>{{cite web|title=A Brief History of Marine Biology and Oceanography|url=http://www.meer.org/ebook/mbhist.htm|access-date=31 March 2014|archive-date=3 August 2020|archive-url=https://web.archive.org/web/20200803202907/http://www.meer.org/ebook/mbhist.htm|url-status=dead}}</ref> The pace of oceanographic and marine biology studies quickly accelerated during the course of the 19th century.
Source: [[List of biologists]].

[[File:Challenger.jpg|thumb|right|{{center|{{HMS|Challenger|1858|6}} during its [[Challenger expedition|pioneer expedition]] of 1872–1876}}]]

The observations made in the first studies of marine biology fueled the [[Age of Discovery]] and exploration that followed. During this time, a vast amount of knowledge was gained about the life that exists in the oceans of the world. Many voyages contributed significantly to this pool of knowledge. Among the most significant were the voyages of {{HMS|Beagle}} where [[Charles Darwin]] came up with his theories of [[evolution]] and on the formation of [[coral reefs]].<ref>Ward, Ritchie R. Into the ocean world; the biology of the sea. 1st ed. New York: Knopf; [distributed by Random House], 1974: 161</ref> Another important expedition was undertaken by [[HMS Challenger (1858)|HMS ''Challenger'']], where findings were made of unexpectedly high [[species diversity]] among [[fauna]] stimulating much theorizing by population ecologists on how such varieties of life could be maintained in what was thought to be such a hostile environment.<ref>Gage, John D., and Paul A. Tyler. Deep-sea biology: a natural history of organisms at the deep-sea floor. Cambridge: Cambridge University Press, 1991: 1</ref> This era was important for the history of marine biology but naturalists were still limited in their studies because they lacked technology that would allow them to adequately examine species that lived in deep parts of the oceans.

The creation of marine laboratories was important because it allowed marine biologists to conduct research and process their specimens from expeditions. The oldest marine laboratory in the world, [[Station biologique de Roscoff]], was established in Concarneau, France founded by the College of France in 1859.<ref>{{Cite web|date=2018-06-17|title=A History Of The Study Of Marine Biology ~ MarineBio Conservation Society|url=https://www.marinebio.org/creatures/marine-biology/history-of-marine-biology/|access-date=2022-02-17|language=en-US}}</ref> In the United States, the [[Scripps Institution of Oceanography]] dates back to 1903, while the prominent [[Woods Hole Oceanographic Institute]] was founded in 1930.<ref>Maienschein, Jane. 100 years exploring life, 1888-1988: the Marine Biological Laboratory at Woods Hole. Boston: Jones and Bartlett Publishers, 1989: 189-192</ref> The development of technology such as sound navigation ranging, scuba diving gear, submersibles and remotely operated vehicles allowed marine biologists to discover and explore life in deep oceans that was once thought to not exist.<ref>{{cite web|last=Anderson|first=Genny|title=Beginnings: History of Marine Science|url=http://marinebio.net/marinescience/01intro/behist.htm}} </ref> Public interest in the subject continued to develop in the post-war years with the publication of [[Rachel Carson]]`s sea trilogy (1941-1955).
{{Further|Sonic characteristics of marine species}}


== See also ==
== See also ==
{{Portal|Environment|Ecology|Earth sciences|Marine life|Oceans|Water|Underwater diving}}
[[Image:Georgia Aquarium - Giant Grouper edit.jpg|right|thumb|A [[giant grouper]].]]
{{Div col|colwidth=30em}}
* [[Algae]]
* [[Acoustic ecology]]
* ''[[Aliens of the Deep]]'' (documentary)
* [[Bioerosion]]
* [[Aquaculture]]
* [[Bathymetry]]
* [[Census of Marine Life]] (CoML)
* [[Fish]]
* [[Biological oceanography]]
*[[Effects of climate change on oceans]]
* [[Freshwater biology]]
* [[Freshwater biology]]
* [[Modular ocean model]]
* [[List of publications in biology#Marine biology|Important publications in marine biology]]
* [[Oceanic basin]]
* [[Institute for Marine Mammal Studies]]
* [[The Marine Mammal Center]]
* [[Oceanic climate]]
* [[Marine vertebrates]]
* [[Marine debris]]
* [[Ocean]]
* [[Ocean Biogeographic Information System]] (OBIS)
* [[Phycology]]
* [[Phycology]]
{{div col end}}
* [[Public aquarium]]

* [[Sea]]
=== Lists ===
* [[Wembury Marine Centre]]
{{Div col|colwidth=30em}}
* [[White Sea Biological Station]]
* [[Glossary of ecology]]
* [[Index of biology articles]]
* [[Large marine ecosystem]]
* [[List of ecologists]]
* [[List of marine biologists]]
* [[List of marine ecoregions (WWF)]]
* [[Outline of biology]]
* [[Outline of ecology]]
{{div col end}}


== References ==
== References ==
{{reflist|2}}
{{reflist|32em}}

== Further references ==
* Morrissey J and Sumich J (2011) [https://books.google.com/books?id=2cm_s-I01kcC&q=%22Introduction+to+the+Biology+of+Marine+Life%22 ''Introduction to the Biology of Marine Life''] Jones & Bartlett Publishers. {{ISBN|9780763781606}}.
* Mladenov, Philip V., Marine Biology: A Very Short Introduction, 2nd edn (Oxford, 2020; online edn, Very Short Introductions online, Feb. 2020), http://dx.doi.org/10.1093/actrade/9780198841715.001.0001, accessed 21 Jun. 2020.


== External links ==
== External links ==
{{Commons category}}
{{Too many links|date=March 2008}}
* [http://ocean.si.edu/ Smithsonian Ocean Portal]
<!-- This section is linked from [[James Lovelock]] -->
* [http://www.imarest.org/scientist/ The Marine Scientist - the quarterly international magazine for marine scientists]
* [http://www.mcsuk.org/ Marine Conservation Society]
* {{curlie|Science/Biology/Ecology/Aquatic_Ecology/Marine}}
* [http://www.ec.gc.ca/WATER/en/info/facts/e_quantity.htm Global Water Facts, from Environment Canada]
* [https://archive.today/20130111125741/http://www.wileyonlinelibrary.com/journal/maec Marine Ecology – an evolutionary perspective]
* [http://www.animal-job.co.uk/marine-careers.html#other Marine Biologist Career Description]
* [http://onlinelibrary.wiley.com/doi/10.1111/mae.2011.32.issue-s1/issuetoc Free special issue: Marine Biology in Time and Space]
* [http://www.whoi.edu/imageOfDay.do Oceanography Image of the Day], from the Woods Hole Oceanographic Institution
* [https://www.youtube.com/watch?v=iGRJjuMLMgE Creatures of the deep ocean] – ''National Geographic'' documentary, 2010.
* [http://marinebio.org/ MarineBio: an evolving online tribute to Marine Biology and all Ocean life.]
* [http://www.mcsuk.org/ Marine Conservation Society: UK charity for seas and wildlife.]
* [http://www.exploris.org.uk Exploris]
* [http://content.lib.washington.edu/fishweb/index.html Freshwater and Marine Image Bank] – From the University of Washington Library
* [http://www.seaturtle.org/tracking/?tag_id=49818 SeaTurtle.org: Tracking a sea turtle.]
* [http://www.marinetraining.eu Marine Training Portal] {{Webarchive|url=https://web.archive.org/web/20160630085826/http://www.marinetraining.eu/ |date=2016-06-30 }} – Portal grouping training initiatives in the field of Marine Biology
* [http://www.marinebiology.co.uk/ Marinebiology.co.uk a marine biology resource.]
* [http://www.int-res.com/journals/meps/ Marine Ecology Progress Series (MEPS).]
* [http://www.mba.ac.uk/ Marine Biological Association of the United Kingdom.]
* [http://www.marlin.ac.uk/ Marine Life Information Network for Britain and Ireland - ''MarLIN''.]
* [http://content.lib.washington.edu/fishweb/index.html University of Washington Libraries Digital Collections – Freshwater and Marine Image Bank] An ongoing digital collection of images related to freshwater and marine topics.
* [http://www.thedeepbook.org/ "Creatures of the Deep," a photo gallery and Flash video of creatures from the deep ocean.]
* [http://www.usp.br/cbm/oceano Photo exhibit "'''Oceano: vida escondida'''" (Ocean: hidden life) revealing the aesthetics of marine lifeforms], from the Marine Biology Center (CEBIMar) of São Paulo University.
* [http://www.piscoweb.org/ PISCO - Partnership for Interdisciplinary Studies of Coastal Oceans]
* [http://www.meriresearch.org/ The Marine Environmental Research Institute]
* [http://www.oceanservice.noaa.gov/ The National Ocean Service]
* [http://www.getmarinebiologyjobs.com/ Get Marine Biology Jobs, Career portal dedicated exclusively to the field of Marine Biology]
* [http://www.edsoup.com/blog/ready-to-go-to-marine-biology-college-and-become-the-next-jacques-cousteau/ Find Marine Biology Colleges]
* [http://www.wooster.edu/geology/Bioerosion/Bioerosion.html Bioerosion website at The College of Wooster]


{{Biology_nav}}
{{Biology-footer}}
{{Biology-footer}}
{{aquatic ecosystem topics|expanded=marine}}
{{fisheries and fishing}}
{{fishery science topics|state=collapsed}}

{{Underwater diving}}
[[Category:Marine biology|* ]]
{{Authority control}}
[[Category:Biological oceanography|*]]
[[Category:Fisheries|*]]


{{DEFAULTSORT:Marine Biology}}
[[ar:علم الأحياء البحري]]
[[Category:Marine biology| ]]
[[an:Biolochía marina]]
[[Category:Biological oceanography]]
[[ca:Biologia marina]]
[[Category:Fisheries science]]
[[cy:Bioleg forol]]
[[Category:Oceanographical terminology]]
[[da:Marinbiolog]]
[[de:Meeresbiologie]]
[[et:Merebioloogia]]
[[es:Biología marina]]
[[fr:Biologie marine]]
[[ko:해양생물학]]
[[id:Biologi kelautan]]
[[is:Sjávarlíffræði]]
[[it:Biologia marina]]
[[lt:Jūrų biologija]]
[[nl:Mariene biologie]]
[[ja:生物海洋学]]
[[no:Marinbiologi]]
[[nn:Marinbiologi]]
[[pl:Biologia morza]]
[[pt:Biologia marinha]]
[[ru:Биология океана]]
[[simple:Marine biology]]
[[sv:Marinbiologi]]
[[th:ชีววิทยาทางทะเล]]
[[tr:Deniz biyolojisi]]
[[uk:Біологія океану]]
[[ur:بحری حیاتیات]]
[[zh:海洋生物学]]

Latest revision as of 11:33, 26 March 2024

Marine biology studies species (marine life) that live in marine habitats (coastal and open ocean habitats). Clockwise from top left: Tide pool in Santa Cruz, United States; School of barracuda at Pom Pom Island, Malaysia; Fan mussel in a Mediterranean seagrass meadow; Research submarine for marine research.

Marine biology is the scientific study of the biology of marine life, organisms in the sea. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather than on taxonomy.

A large proportion of all life on Earth lives in the ocean. The exact size of this large proportion is unknown, since many ocean species are still to be discovered. The ocean is a complex three-dimensional world[1] covering approximately 71% of the Earth's surface. The habitats studied in marine biology include everything from the tiny layers of surface water in which organisms and abiotic items may be trapped in surface tension between the ocean and atmosphere, to the depths of the oceanic trenches, sometimes 10,000 meters or more beneath the surface of the ocean. Specific habitats include estuaries, coral reefs, kelp forests, seagrass meadows, the surrounds of seamounts and thermal vents, tidepools, muddy, sandy and rocky bottoms, and the open ocean (pelagic) zone, where solid objects are rare and the surface of the water is the only visible boundary. The organisms studied range from microscopic phytoplankton and zooplankton to huge cetaceans (whales) 25–32 meters (82–105 feet) in length. Marine ecology is the study of how marine organisms interact with each other and the environment.

Marine life is a vast resource, providing food, medicine, and raw materials, in addition to helping to support recreation and tourism all over the world. At a fundamental level, marine life helps determine the very nature of our planet. Marine organisms contribute significantly to the oxygen cycle, and are involved in the regulation of the Earth's climate.[2] Shorelines are in part shaped and protected by marine life, and some marine organisms even help create new land.[3]

Many species are economically important to humans, including both finfish and shellfish. It is also becoming understood that the well-being of marine organisms and other organisms are linked in fundamental ways. The human body of knowledge regarding the relationship between life in the sea and important cycles is rapidly growing, with new discoveries being made nearly every day. These cycles include those of matter (such as the carbon cycle) and of air (such as Earth's respiration, and movement of energy through ecosystems including the ocean). Large areas beneath the ocean surface still remain effectively unexplored.

Biological oceanography[edit]

Two views of the ocean from space
Marine biology studies species that live in marine habitats. Most of the Earth's surface is covered by ocean, which is the home to marine life. Oceans average nearly four kilometers in-depth and are fringed with coastlines that run for about 360,000 kilometres.[4][5]

Marine biology can be contrasted with biological oceanography. Marine life is a field of study both in marine biology and in biological oceanography. Biological oceanography is the study of how organisms affect and are affected by the physics, chemistry, and geology of the oceanographic system. Biological oceanography mostly focuses on the microorganisms within the ocean; looking at how they are affected by their environment and how that affects larger marine creatures and their ecosystem.[6] Biological oceanography is similar to marine biology, but it studies ocean life from a different perspective. Biological oceanography takes a bottom up approach in terms of the food web, while marine biology studies the ocean from a top down perspective. Biological oceanography mainly focuses on the ecosystem of the ocean with an emphasis on plankton: their diversity (morphology, nutritional sources, motility, and metabolism); their productivity and how that plays a role in the global carbon cycle; and their distribution (predation and life cycle).[6][7][8] Biological oceanography also investigates the role of microbes in food webs, and how humans impact the ecosystems in the oceans.[6][9]

Marine habitats[edit]

Marine habitats can be divided into coastal and open ocean habitats. Coastal habitats are found in the area that extends from the shoreline to the edge of the continental shelf. Most marine life is found in coastal habitats, even though the shelf area occupies only seven percent of the total ocean area. Open ocean habitats are found in the deep ocean beyond the edge of the continental shelf. Alternatively, marine habitats can be divided into pelagic and demersal habitats. Pelagic habitats are found near the surface or in the open water column, away from the bottom of the ocean and affected by ocean currents, while demersal habitats are near or on the bottom. Marine habitats can be modified by their inhabitants. Some marine organisms, like corals, kelp and sea grasses, are ecosystem engineers which reshape the marine environment to the point where they create further habitat for other organisms.

Intertidal and near shore[edit]

Tide pools with sea stars and sea anemone

Intertidal zones, the areas that are close to the shore, are constantly being exposed and covered by the ocean's tides. A huge array of life can be found within this zone. Shore habitats span from the upper intertidal zones to the area where land vegetation takes prominence. It can be underwater anywhere from daily to very infrequently. Many species here are scavengers, living off of sea life that is washed up on the shore. Many land animals also make much use of the shore and intertidal habitats. A subgroup of organisms in this habitat bores and grinds exposed rock through the process of bioerosion.

Estuaries[edit]

Estuaries have shifting flows of sea water and fresh water.

Estuaries are also near shore and influenced by the tides. An estuary is a partially enclosed coastal body of water with one or more rivers or streams flowing into it and with a free connection to the open sea.[10] Estuaries form a transition zone between freshwater river environments and saltwater maritime environments. They are subject both to marine influences—such as tides, waves, and the influx of saline water—and to riverine influences—such as flows of fresh water and sediment. The shifting flows of both sea water and fresh water provide high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world.[11]

Reefs[edit]

Coral reefs form complex marine ecosystems with tremendous biodiversity.

Reefs comprise some of the densest and most diverse habitats in the world. The best-known types of reefs are tropical coral reefs which exist in most tropical waters; however, reefs can also exist in cold water. Reefs are built up by corals and other calcium-depositing animals, usually on top of a rocky outcrop on the ocean floor. Reefs can also grow on other surfaces, which has made it possible to create artificial reefs. Coral reefs also support a huge community of life, including the corals themselves, their symbiotic zooxanthellae, tropical fish and many other organisms.

Much attention in marine biology is focused on coral reefs and the El Niño weather phenomenon. In 1998, coral reefs experienced the most severe mass bleaching events on record, when vast expanses of reefs across the world died because sea surface temperatures rose well above normal.[12][13] Some reefs are recovering, but scientists say that between 50% and 70% of the world's coral reefs are now endangered and predict that global warming could exacerbate this trend.[14][15][16][17]

Some representative ocean animal life (not drawn to scale) within their approximate depth-defined ecological habitats. Marine microorganisms exist on the surfaces and within the tissues and organs of the diverse life inhabiting the ocean, across all ocean habitats.[18]

Open ocean[edit]

The open ocean is the area of deep sea beyond the continental shelves.

The open ocean is relatively unproductive because of a lack of nutrients, yet because it is so vast, in total it produces the most primary productivity. The open ocean is separated into different zones, and the different zones each have different ecologies.[19] Zones which vary according to their depth include the epipelagic, mesopelagic, bathypelagic, abyssopelagic, and hadopelagic zones. Zones which vary by the amount of light they receive include the photic and aphotic zones. Much of the aphotic zone's energy is supplied by the open ocean in the form of detritus.

Deep sea and trenches[edit]

A deep-sea chimaera. Its snout is covered with tiny pores capable of detecting animals by perturbations in electric fields.

The deepest recorded oceanic trench measured to date is the Mariana Trench, near the Philippines, in the Pacific Ocean at 10,924 m (35,840 ft). At such depths, water pressure is extreme and there is no sunlight, but some life still exists. A white flatfish, a shrimp and a jellyfish were seen by the American crew of the bathyscaphe Trieste when it dove to the bottom in 1960.[20] In general, the deep sea is considered to start at the aphotic zone, the point where sunlight loses its power of transference through the water.[21] Many life forms that live at these depths have the ability to create their own light known as bio-luminescence. Marine life also flourishes around seamounts that rise from the depths, where fish and other sea life congregate to spawn and feed. Hydrothermal vents along the mid-ocean ridge spreading centers act as oases, as do their opposites, cold seeps. Such places support unique biomes and many new microbes and other lifeforms have been discovered at these locations.[22]

Marine life[edit]

Mature salmon with fungal disease
Albatross hovering over the ocean looking for prey

In biology many phyla, families and genera have some species that live in the sea and others that live on land. Marine biology classifies species based on the environment rather than on taxonomy. For this reason marine biology encompasses not only organisms that live only in a marine environment, but also other organisms whose lives revolve around the sea.

Microscopic life[edit]

As inhabitants of the largest environment on Earth, microbial marine systems drive changes in every global system. Microbes are responsible for virtually all the photosynthesis that occurs in the ocean, as well as the cycling of carbon, nitrogen, phosphorus and other nutrients and trace elements.[23]

Microscopic life undersea is incredibly diverse and still poorly understood. For example, the role of viruses in marine ecosystems is barely being explored even in the beginning of the 21st century.[24]

The role of phytoplankton is better understood due to their critical position as the most numerous primary producers on Earth. Phytoplankton are categorized into cyanobacteria (also called blue-green algae/bacteria), various types of algae (red, green, brown, and yellow-green), diatoms, dinoflagellates, euglenoids, coccolithophorids, cryptomonads, chrysophytes, chlorophytes, prasinophytes, and silicoflagellates.

Zooplankton tend to be somewhat larger, and not all are microscopic. Many Protozoa are zooplankton, including dinoflagellates, zooflagellates, foraminiferans, and radiolarians. Some of these (such as dinoflagellates) are also phytoplankton; the distinction between plants and animals often breaks down in very small organisms. Other zooplankton include cnidarians, ctenophores, chaetognaths, molluscs, arthropods, urochordates, and annelids such as polychaetes. Many larger animals begin their life as zooplankton before they become large enough to take their familiar forms. Two examples are fish larvae and sea stars (also called starfish).

Plants and algae[edit]

Microscopic algae and plants provide important habitats for life, sometimes acting as hiding places for larval forms of larger fish and foraging places for invertebrates.

Algal life is widespread and very diverse under the ocean. Microscopic photosynthetic algae contribute a larger proportion of the world's photosynthetic output than all the terrestrial forests combined. Most of the niche occupied by sub plants on land is actually occupied by macroscopic algae in the ocean, such as Sargassum and kelp, which are commonly known as seaweeds that create kelp forests.

Plants that survive in the sea are often found in shallow waters, such as the seagrasses (examples of which are eelgrass, Zostera, and turtle grass, Thalassia). These plants have adapted to the high salinity of the ocean environment. The intertidal zone is also a good place to find plant life in the sea, where mangroves or cordgrass or beach grass might grow.

Invertebrates[edit]

As on land, invertebrates make up a huge portion of all life in the sea. Invertebrate sea life includes Cnidaria such as jellyfish and sea anemones; Ctenophora; sea worms including the phyla Platyhelminthes, Nemertea, Annelida, Sipuncula, Echiura, Chaetognatha, and Phoronida; Mollusca including shellfish, squid, octopus; Arthropoda including Chelicerata and Crustacea; Porifera; Bryozoa; Echinodermata including starfish; and Urochordata including sea squirts or tunicates. Invertebrates have no backbone. There are over a million species.

Fungi[edit]

Over 10,000[25] species of fungi are known from marine environments.[26] These are parasitic on marine algae or animals, or are saprobes on algae, corals, protozoan cysts, sea grasses, wood and other substrata, and can also be found in sea foam.[27] Spores of many species have special appendages which facilitate attachment to the substratum.[28] A very diverse range of unusual secondary metabolites is produced by marine fungi.[29]

Vertebrates[edit]

Fish[edit]

A reported 33,400 species of fish, including bony and cartilaginous fish, had been described by 2016,[30] more than all other vertebrates combined. About 60% of fish species live in saltwater.[31]

Reptiles[edit]

Reptiles which inhabit or frequent the sea include sea turtles, sea snakes, terrapins, the marine iguana, and the saltwater crocodile. Most extant marine reptiles, except for some sea snakes, are oviparous and need to return to land to lay their eggs. Thus most species, excepting sea turtles, spend most of their lives on or near land rather than in the ocean. Despite their marine adaptations, most sea snakes prefer shallow waters nearby land, around islands, especially waters that are somewhat sheltered, as well as near estuaries.[32][33] Some extinct marine reptiles, such as ichthyosaurs, evolved to be viviparous and had no requirement to return to land.

Birds[edit]

Birds adapted to living in the marine environment are often called seabirds. Examples include albatross, penguins, gannets, and auks. Although they spend most of their lives in the ocean, species such as gulls can often be found thousands of miles inland.

Mammals[edit]

There are five main types of marine mammals, namely cetaceans (toothed whales and baleen whales); sirenians such as manatees; pinnipeds including seals and the walrus; sea otters; and the polar bear. All are air-breathing, and while some such as the sperm whale can dive for prolonged periods, all must return to the surface to breathe.[34][35]

Subfields[edit]

The marine ecosystem is large, and thus there are many sub-fields of marine biology. Most involve studying specializations of particular animal groups, such as phycology, invertebrate zoology and ichthyology. Other subfields study the physical effects of continual immersion in sea water and the ocean in general, adaptation to a salty environment, and the effects of changing various oceanic properties on marine life. A subfield of marine biology studies the relationships between oceans and ocean life, and global warming and environmental issues (such as carbon dioxide displacement). Recent marine biotechnology has focused largely on marine biomolecules, especially proteins, that may have uses in medicine or engineering. Marine environments are the home to many exotic biological materials that may inspire biomimetic materials.

Through constant monitoring of the ocean, there have been discoveries of marine life which could be used to create remedies for certain diseases such as cancer and leukemia. In addition, Ziconotide, an approved drug used to treat pain, was created from a snail which resides in the ocean.[36]

Related fields[edit]

Marine biology is a branch of biology. It is closely linked to oceanography, especially biological oceanography, and may be regarded as a sub-field of marine science. It also encompasses many ideas from ecology. Fisheries science and marine conservation can be considered partial offshoots of marine biology (as well as environmental studies). Marine Chemistry, Physical oceanography and Atmospheric sciences are closely related to this field.

Distribution factors[edit]

An active research topic in marine biology is to discover and map the life cycles of various species and where they spend their time. Technologies that aid in this discovery include pop-up satellite archival tags, acoustic tags, and a variety of other data loggers. Marine biologists study how the ocean currents, tides and many other oceanic factors affect ocean life forms, including their growth, distribution and well-being. This has only recently become technically feasible with advances in GPS and newer underwater visual devices.[37]

Most ocean life breeds in specific places, nests or not in others, spends time as juveniles in still others, and in maturity in yet others. Scientists know little about where many species spend different parts of their life cycles especially in the infant and juvenile years. For example, it is still largely unknown where juvenile sea turtles and some year-1 sharks travel. Recent advances in underwater tracking devices are illuminating what we know about marine organisms that live at great Ocean depths.[38] The information that pop-up satellite archival tags give aids in certain time of the year fishing closures and development of a marine protected area. This data is important to both scientists and fishermen because they are discovering that by restricting commercial fishing in one small area they can have a large impact in maintaining a healthy fish population in a much larger area.

History[edit]

Aristotle recorded that the embryo of a dogfish was attached by a cord to a kind of placenta (the yolk sac).[39]

The study of marine biology dates to Aristotle (384–322 BC), who made many observations of life in the sea around Lesbos, laying the foundation for many future discoveries.[40] In 1768, Samuel Gottlieb Gmelin (1744–1774) published the Historia Fucorum, the first work dedicated to marine algae and the first book on marine biology to use the new binomial nomenclature of Linnaeus. It included elaborate illustrations of seaweed and marine algae on folded leaves.[41][42] The British naturalist Edward Forbes (1815–1854) is generally regarded as the founder of the science of marine biology.[43] The pace of oceanographic and marine biology studies quickly accelerated during the course of the 19th century.

HMS Challenger during its pioneer expedition of 1872–1876

The observations made in the first studies of marine biology fueled the Age of Discovery and exploration that followed. During this time, a vast amount of knowledge was gained about the life that exists in the oceans of the world. Many voyages contributed significantly to this pool of knowledge. Among the most significant were the voyages of HMS Beagle where Charles Darwin came up with his theories of evolution and on the formation of coral reefs.[44] Another important expedition was undertaken by HMS Challenger, where findings were made of unexpectedly high species diversity among fauna stimulating much theorizing by population ecologists on how such varieties of life could be maintained in what was thought to be such a hostile environment.[45] This era was important for the history of marine biology but naturalists were still limited in their studies because they lacked technology that would allow them to adequately examine species that lived in deep parts of the oceans.

The creation of marine laboratories was important because it allowed marine biologists to conduct research and process their specimens from expeditions. The oldest marine laboratory in the world, Station biologique de Roscoff, was established in Concarneau, France founded by the College of France in 1859.[46] In the United States, the Scripps Institution of Oceanography dates back to 1903, while the prominent Woods Hole Oceanographic Institute was founded in 1930.[47] The development of technology such as sound navigation ranging, scuba diving gear, submersibles and remotely operated vehicles allowed marine biologists to discover and explore life in deep oceans that was once thought to not exist.[48] Public interest in the subject continued to develop in the post-war years with the publication of Rachel Carson`s sea trilogy (1941-1955).

See also[edit]

Lists[edit]

References[edit]

  1. ^ Oceanographic and Bathymetric Features Marine Conservation Institute. Uploaded 18 September 2013.
  2. ^ Foley, Jonathan A.; Taylor, Karl E.; Ghan, Steven J. (1991). "Planktonic dimethylsulfide and cloud albedo: An estimate of the feedback response". Climatic Change. 18 (1): 1. Bibcode:1991ClCh...18....1F. doi:10.1007/BF00142502. S2CID 154990993.
  3. ^ Sousa, Wayne P. (1986) [1985]. "7, Disturbance and Patch Dynamics on Rocky Intertidal Shores". In Pickett, Steward T. A.; White, P. S. (eds.). The Ecology of Natural Disturbance and Patch Dynamics. Academic Press. ISBN 978-0-12-554521-1.
  4. ^ Charette, Matthew; Smith, Walter H. F. (2010). "The volume of Earth's ocean". Oceanography. 23 (2): 112–114. doi:10.5670/oceanog.2010.51. hdl:1912/3862.
  5. ^ World The World Factbook, CIA. Retrieved 13 January 2014.
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  7. ^ Menden-Deuer, Susanne. "Course Info, OCG 561 Biological Oceanography". Archived from the original on 2018-01-29. Retrieved 2021-03-19.
  8. ^ Miller, Charles B.; Patricia A. Wheeler (2012). Biological Oceanography (Second ed.). Chinchester, West Sussex: John Wiley & Sons.
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  13. ^ ICRS (1998) Statement on Global Coral Bleaching in 1997-1998. International Coral Reef Society, October 15, 1998.
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  16. ^ Sebens, K. P. (1994). "Biodiversity of Coral Reefs: What are We Losing and Why?". Am. Zool. 34: 115–133. doi:10.1093/icb/34.1.115.
  17. ^ Wilkinson, C. R., and Buddemeier, R. W. (1994) "Global Climate Change and Coral Reefs:Implications for People and Reefs". Report of the UNEP-IOC-ASPEI-IUCN Global Task Team on the Implications of Climate Change on Coral Reefs. IUCN, Gland, Switzerland.
  18. ^ Apprill, A. (2017)"Marine animal microbiomes: toward understanding host–microbiome interactions in a changing ocean". Frontiers in Marine Science, 4: 222. doi:10.3389/fmars.2017.00222. Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
  19. ^ "The Open Ocean - MarineBio.org". marinebio.org. Retrieved 2016-09-26.
  20. ^ Seven Miles Down: The Story of The Bathyscaph Trieste. Archived 2007-02-02 at the Wayback Machine, Rolex Deep Sea Special, January 2006.
  21. ^ "Aphotic Zone | Encyclopedia.com". www.encyclopedia.com. Retrieved 2018-12-06.
  22. ^ Priede, Imants G. (10 August 2017). Deep-Sea Fishes: Biology, Diversity, Ecology and Fisheries. Cambridge University Press. pp. 12–13. ISBN 9781107083820.
  23. ^ "Functions of global ocean microbiome key to understanding environmental changes". www.sciencedaily.com. University of Georgia. December 10, 2015. Retrieved December 11, 2015.
  24. ^ Suttle, C.A. (2005). "Viruses in the Sea". Nature. 437 (9): 356–361. Bibcode:2005Natur.437..356S. doi:10.1038/nature04160. PMID 16163346. S2CID 4370363.
  25. ^ Amend, Anthony; Burgaud, Gaetan; Cunliffe, Michael; Edgcomb, Virginia P.; Ettinger, Cassandra L.; Gutiérrez, M. H.; Heitman, Joseph; Hom, Erik F. Y.; Ianiri, Giuseppe; Jones, Adam C.; Kagami, Maiko (2019-03-05). "Fungi in the Marine Environment: Open Questions and Unsolved Problems". mBio. 10 (2). doi:10.1128/mBio.01189-18. PMC 6401481. PMID 30837337. S2CID 73481006.[permanent dead link]
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