Marine biology 1

Marine biology

World Marine Environment.

Marine biology is the scientific study of organisms in the ocean orother marine or brackish bodies of water. Given that in biology manyphyla, families and genera have some species that live in the sea andothers that live on land, marine biology classifies species based on theenvironment rather than on taxonomy. Marine biology differs frommarine ecology as marine ecology is focused on how organismsinteract with each other and the environment, and biology is the studyof the organisms themselves.

Marine life is a vast resource, providing food, medicine, and rawmaterials, in addition to helping to support recreation and tourism allover the world. At a fundamental level, marine life helps determine thevery nature of our planet. Marine organisms contribute significantly tothe oxygen cycle, and are involved in the regulation of the Earth'sclimate.[1] Shorelines are in part shaped and protected by marine life, and some marine organisms even help createnew land.[2]

Marine biology covers a great deal, from the microscopic, including most zooplankton and phytoplankton to thehuge cetaceans (whales) which reach up to a reported 48 meters (125 feet) in length.The habitats studied by marine biology include everything from the tiny layers of surface water in which organismsand abiotic items may be trapped in surface tension between the ocean and atmosphere, to the depths of the oceanictrenches, sometimes 10,000 meters or more beneath the surface of the ocean. It studies habitats such as coral reefs,kelp forests, tidepools, muddy, sandy and rocky bottoms, and the open ocean (pelagic) zone, where solid objects arerare and the surface of the water is the only visible boundary.A large amount of all life on Earth exists in the oceans. Exactly how large the proportion is unknown, since manyocean species are still to be discovered. While the oceans comprise about 71% of the Earth's surface, due to theirdepth they encompass about 300 times the habitable volume of the terrestrial habitats on Earth.Many species are economically important to humans, including food fish. It is also becoming understood that thewell-being of marine organisms and other organisms are linked in very fundamental ways. The human body ofknowledge regarding the relationship between life in the sea and important cycles is rapidly growing, with newdiscoveries 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 beneaththe ocean surface still remain effectively unexplored.

SubfieldsThe marine ecosystem is large, and thus there are many subfields of marine biology. Most involve studyingspecializations 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 toa salty environment, and the effects of changing various oceanic properties on marine life. A subfield of marinebiology studies the relationships between oceans and ocean life, and global warming and environmental issues (suchas carbon dioxide displacement).Recent marine biotechnology has focused largely on marine biomolecules, especially proteins, that may have uses inmedicine or engineering. Marine environments are the home to many exotic biological materials that may inspirebiomimetic materials.

Marine biology 2

Related fieldsMarine biology is a branch of oceanography and is closely linked to biology. It also encompasses many ideas fromecology. Fisheries science and marine conservation can be considered partial offshoots of marine biology (as well asenvironmental studies).

Lifeforms

Microscopic life

A copepod.

Microscopic life undersea is incredibly diverse and still poorlyunderstood. For example, the role of viruses in marine ecosystems isbarely being explored even in the beginning of the 21st century.

The role of phytoplankton is better understood due to their criticalposition as the most numerous primary producers on Earth.Phytoplankton are categorized into cyanobacteria (also calledblue-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, includingdinoflagellates, zooflagellates, foraminiferans, and radiolarians. Some of these (such as dinoflagellates) are alsophytoplankton; the distinction between plants and animals often breaks down in very small organisms. Otherzooplankton include cnidarians, ctenophores, chaetognaths, molluscs, arthropods, urochordates, and annelids such aspolychaetes. Many larger animals begin their life as zooplankton before they become large enough to take theirfamiliar forms. Two examples are fish larvae and sea stars (also called starfish).

Plants and algaePlant life is widespread and very diverse under the ocean. Microscopic photosynthetic algae contribute a largerproportion of the worlds photosynthetic output than all the terrestrial forests combined. Most of the niche occupiedby sub plants on land is actually occupied by macroscopic algae in the ocean, such as Sargassum and kelp, which arecommonly known as seaweeds that creates kelp forests. The non algae plants that survive in the sea are often foundin 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 tofind plant life in the sea, where mangroves or cordgrass or beach grass might grow. Microscopic algae and plantsprovide important habitats for life, sometimes acting as hiding and foraging places for larval forms of larger fish andinvertebrates.

Marine biology 3

A crown-of-thorns starfish.

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 seaanemones; Ctenophora; sea worms including the phylaPlatyhelminthes, Nemertea, Annelida, Sipuncula, Echiura,Chaetognatha, and Phoronida; Mollusca including shellfish, squid,octopus; Arthropoda including Chelicerata and Crustacea; Porifera;Bryozoa; Echinodermata including starfish; and Urochordata includingsea squirts or tunicates.

FishFish have evolved very different biological functions from other large organisms. Fish anatomy includes atwo-chambered heart, operculum, swim bladder, scales, fins, lips, eyes and secretory cells that produce mucous. Fishbreathe by extracting oxygen from water through their gills. Fins propel and stabilize the fish in the water.Well known fish include: sardines, anchovy, ling cod, clownfish (also known as anemonefish), and bottom fishwhich include halibut or ling cod. Predators include sharks and barracuda.

Green turtle.

Reptiles

Reptiles which inhabit or frequent the sea include sea turtles, seasnakes, terrapins, the marine iguana, and the saltwater crocodile. Mostextant marine reptiles, except for some sea snakes, are oviparous andneed to return to land to lay their eggs. Thus most species, exceptingsea turtles, spend most of their lives on or near land rather than in theocean. Despite their marine adaptations, most sea snakes prefershallow waters nearby land, around islands, especially waters that aresomewhat sheltered, as well as near estuaries.[3] [4] Some extinctmarine reptiles, such as ichthyosaurs, evolved to be viviparous and hadno requirement to return to land.

Marine biology 4

SeabirdsSeabirds are species of birds adapted to living in the marine environment, examples including albatross, penguins,gannets, and auks. Although they spend most of their lives in the ocean, species such as gulls can often be foundthousands of miles inland.

Sea otters.

Marine mammals

There are five main types of marine mammals.• Cetaceans include toothed whales (Suborder Odontoceti), such as

the Sperm Whale, dolphins, and porpoises such as the Dall'sporpoise. Cetaceans also include baleen whales (SuborderMysticeti), such as the Gray Whale, Humpback Whale, and BlueWhale.

• Sirenians include manatees, the Dugong, and the extinct Steller'sSea Cow.

• Seals (Family Phocidae), sea lions (Family Otariidae - which alsoinclude the fur seals), and the Walrus (Family Odobenidae) are all considered pinnipeds.

• The Sea Otter is a member of the Family Mustelidae, which includes weasels and badgers.• The Polar Bear (Family Ursidae) is sometimes considered a marine mammal because of its dependence on the

sea.

Oceanic habitats

ReefsReefs comprise some of the densest and most diverse habitats in the world. The best-known types of reefs aretropical coral reefs which exist in most tropical waters; however, reefs can also exist in cold water. Reefs are built upby corals and other calcium-depositing animals, usually on top of a rocky outcrop on the ocean floor. Reefs can alsogrow on other surfaces, which has made it possible to create artificial reefs. Coral reefs also support a hugecommunity of life, including the corals themselves, their symbiotic zooxanthellae, tropical fish and many otherorganisms.Much attention in marine biology is focused on coral reefs and the El Niño weather phenomenon. In 1998, coralreefs experienced the most severe mass bleaching events on record, when vast expanses of reefs across the worlddied because sea surface temperatures rose well above normal.[5] [6] Some reefs are recovering, but scientists say thatbetween 50% and 70% of the world's coral reefs are now endangered and predict that global warming couldexacerbate this trend.[7] [8] [9] [10]

Deep sea and trenchesThe deepest recorded oceanic trenches measure to date is the Mariana Trench, near the Philippines, in the PacificOcean at 10,924 m (35,838 ft). At such depths, water pressure is extreme and there is no sunlight, but some life stillexists. A white flatfish, a shrimp and a jellyfish were seen by the American crew of the bathyscaphe Trieste when itdove to the bottom in 1960.[11]

Other notable oceanic trenches include Monterey Canyon, in the eastern Pacific, the Tonga Trench in the southwestat 10,882 m (35,702 ft), the Philippine Trench, the Puerto Rico Trench at 8,605 m (28,232 ft), the Romanche Trenchat 7,760 m (24,450 ft), Fram Basin in the Arctic Ocean at 4,665 m (15,305 ft), the Java Trench at 7450 m (24,442 ft),and the South Sandwich Trench at 7,235 m (23,737 ft).

Marine biology 5

In general, the deep sea is considered to start at the aphotic zone, the point where sunlight loses its power oftransference through the water. Many life forms that live at these depths have the ability to create their own light aunique evolution known as bio-luminescence.Marine life also flourishes around seamounts that rise from the depths, where fish and other sea life congregate tospawn 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 atthese locations .

Open oceanThe open ocean is relatively unproductive because of a lack of nutrients, yet because it is so vast, in total it producesthe most primary productivity. Much of the aphotic zone's energy is supplied by the open ocean in the form ofdetritus. The open ocean consists mostly of jellyfish and its predators such as the mola mola.

Intertidal and shore

Tide pools with sea stars and sea anemone in SantaCruz, California

Intertidal zones, those areas close to shore, are constantly beingexposed and covered by the ocean's tides. A huge array of lifelives within this zone.

Shore habitats span from the upper intertidal zones to the areawhere land vegetation takes prominence. It can be underwateranywhere from daily to very infrequently. Many species here arescavengers, living off of sea life that is washed up on the shore.Many land animals also make much use of the shore and intertidalhabitats. A subgroup of organisms in this habitat bores and grindsexposed rock through the process of bioerosion.

Distribution factors

An active research topic in marine biology is to discover and map the life cycles of various species and where theyspend their time. Marine biologists study how the ocean currents, tides and many other oceanic factors affect oceanlifeforms, including their growth, distribution and well-being. This has only recently become technically feasiblewith advances in GPS and newer underwater visual devices.

Most ocean life breeds in specific places, nests or not in others, spends time as juveniles in still others, and inmaturity in yet others. Scientists know little about where many species spend different parts of their life cycles. Forexample, it is still largely unknown where sea turtles and some sharks travel. Tracking devices do not work for somelife forms, and the ocean is not friendly to technology. This is important to scientists and fishermen because they arediscovering that by restricting commercial fishing in one small area they can have a large impact in maintaining ahealthy fish population in a much larger area far away.

Marine biology 6

Lists• Glossary of ecology• Index of biology articles• Large marine ecosystem• List of ecologists• List of important publications in biology#Ecology• List of marine biologists• List of marine ecoregions (WWF)• Outline of biology• Outline of ecology

References[1] Foley, Jonathan A.; Karl E. Taylor, Steven J. Ghan (1991). "Planktonic dimethylsulfide and cloud albedo: An estimate of the feedback

response" (http:/ / www. springerlink. com/ content/ hm3h1q666x206h46). Climatic Change 18 (1): 1. doi:10.1007/BF00142502. .[2] Sousa, Wayne P (1986) [1985]. "7, Disturbance and Patch Dynamics on Rocky Intertidal Shores" (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). The Ecology of Natural Disturbance and Patch Dynamics. eds. Steward T. A. Pickett & P. S.White. Academic Press. ISBN 0125545215. .

[3] Stidworthy J. 1974. Snakes of the World. Grosset & Dunlap Inc. 160 pp. ISBN 0-448-11856-4.[4] Sea snakes (ftp:/ / ftp. fao. org/ docrep/ fao/ 009/ y0870e/ y0870e65. pdf) at Food and Agriculture Organization of the United Nations (http:/ /

www. fao. org/ ). Accessed 7 August 2007.[5] NOAA (1998) Record-breaking coral bleaching occurred in tropics this year. National Oceanic and Atmospheric Administration, Press

release (October 23, 1998).[6] ICRS (1998) Statement on Global Coral Bleaching in 1997-1998. International Coral Reef Society, October 15, 1998.[7] 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.[8] Goreau, T. J. (1992) "Bleaching and Reef Commumity Change in Jamaica: 1951 - 1991". Amer. Zool. 32: 683-695.[9] Sebens, K. P. (1994) "Biodiversity of Coral Reefs: What are We Losing and Why?" Amer Zool, 34: 115-133[10] 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.[11] Seven Miles Down: The Story of The Bathyscaph Trieste. (http:/ / bjsonline. com/ watches/ articles/ 0022_3. shtml), Rolex Deep Sea

Special, January 2006.

External links• Smithsonian Ocean Portal (http:/ / ocean. si. edu/ )• Marine biology (http:/ / www. dmoz. org/ Science/ Biology/ Ecology/ Aquatic_Ecology/ Marine/ ) at the Open

Directory Project

Article Sources and Contributors 7

Article Sources and ContributorsMarine biology  Source: http://en.wikipedia.org/w/index.php?oldid=417730120  Contributors: 1exec1, 867-5309, A3RO, APH, Aaronownesfrod, Access Denied, Adashiel, Aditya, AlanLiefting, Alansohn, Alex43223, AlexWaelde, Allmightyduck, Ams80, Andonic, Andy M. Wang, Anilocra, Animum, Anlace, Anna Lincoln, Anonymi, Anonymous101, Antandrus, Apha,ArglebargleIV, Arnejohs, Arthur Rubin, Aspen winters, Astropithicus, AtheWeatherman, Avicennasis, Avono, Ayudante, Bachrach44, BanRay, Barbara Shack, Bart133, Benbest, Bento00,Bhound89, Biker Biker, Binary TSO, Black Falcon, Blanchardb, Bo Lindbergh, Bob090, Bob0909, Bobo192, Bongwarrior, BorgQueen, Brian Crawford, Brittany-Dawnn, Brittsyourgirl,Broncos099, BrotherGeorge, Bsadowski1, BuickCenturyDriver, CALR, CIreland, Caknuck, Calliopejen1, Calmer Waters, Calvin 1998, CambridgeBayWeather, Can't sleep, clown will eat me,Canadian-Bacon, Cantus, Caprice7, Capricorn42, Celticbattlepants, Centrx, Charlieb63, CharlotteWebb, Chowbok, Clayoquot, Cokeboy01, CommonsDelinker, Conny, Conversion script, CoolBlue, Corvus cornix, Craigy144, CrazyChemGuy, Crepuscular Dawn, Cronulla2230, Crookshankz227, D, DARTH SIDIOUS 2, DMacks, DanMS, Daniel Vaulot, Danski14, Darth Panda,Darthgriz98, Daycd, Dblobaum, Decltype, Dekisugi, Delldot, DerHexer, Diadema8, Discospinster, DiverDave, Diverman, Dj Capricorn, Dlohcierekim, Dolphin51, Doyley, Dr.alf,DragonflySixtyseven, Dreadstar, Drgarden, Drunken Pirate, Dspradau, Dysepsion, Dysprosia, ESkog, Easchiff, EcoForecast, Edderso, Eequor, El C, EnglishEfternamn, Epastore, Epbr123,Epipelagic, Everyking, Evilriku50, Excirial, Exert, Extremetray, Facembanorth, Falcon8765, Fang 23, Faradayplank, Fast For Word, Favonian, Fieldday-sunday, FisherQueen, Fjbfour,Flyguy649, Folantin, Footballfan190, FrYGuY, Frazzydee, Freakmighty, Freemarket, FreplySpang, Fribbler, Fyyer, Fæ, Gaius Cornelius, Gary King, Gcm, Gene Nygaard, Geneb1955, GeorgeThe Dragon, Gfoley4, Gianfranco, Giftlite, Gilliam, Gimme danger, Glenfarclas, Gogo Dodo, Gogoxdontxgo, Grim23, Gurch, Gurchzilla, Gwib, Gökhan, HH0792, Harland1, Hawaiian717,Hdynes, Hektor, Henrik, Hhbruun, Himynameisjim, Hobartimus, Honguy86, Hydrogen Iodide, Hyokano, IRP, Iamwisesun, Igoldste, Iheartwiki19, Ikiroid, Indici, Insanity Incarnate, Ipatrol,Iridescent, IrisKawling, IronGargoyle, Ixfd64, J.delanoy, JForget, JNW, JSpung, Jagz, JamesAM, JamesBWatson, Jan1nad, Jao, JavierMC, Jeepday, Jeremythetacomaster, JesseW, Jga49143,Jimmmmy, Jimothytrotter, Jimp, Jj137, John254, JohnCD, Jojhutton, Jojojoanna123, Jon186, Jose Ramos, Journalist12, Joyous!, Jrockley, Jusdafax, Kapinator333, Karmosin, Karol Langner,Katherine, Katherine Tredwell, Kavin93, Kbh3rd, Keilana, Keithbennett101, Kijoon Hur, Kku, Kmartin, KnowledgeOfSelf, Kormos369, Krich, Kronermark, Kubigula, Kubra, Kukini, Kuru,Kwsn, L Kensington, L'Aquatique, La Pianista, Lamlenguyen, Lankiveil, Lazylaces, LeaveSleaves, Lerdthenerd, Lexor, Liam Mason, Lightmouse, Lillypinkj, Lumos3, M1ss1ontomars2k4,MBisanz, MER-C, Maelor, Mamasita5678, Mandarax, Mannafredo, Maraj, Marek69, Marilynnmatherson, Marinecreatures, Mark.murphy, Markrr, Markthemexicanmonkey, Martial75, Maryquite contrary, Matt Crypto, Maurreen, Mav, Mayumashu, Mbaha, Mbz1, Megan1967, Melchoir, Michael Hardy, Michal Nebyla, Microtony, Mike Rosoft, MikeNish, Mikemoral,MissAmericaGirl, Mo0, Monterey Bay, Mortboy13, Motheate999, Mrfish33, Mukkakukaku, My Cat inn, My name, Mygerardromance, N2e, NERIC-Security, Namiba, Nburden, Ndenison,NeLaS, NellieBly, Neparis, Neutrality, NewHorizons45, Nick C, NickW557, NigelR, Nodyarg, NorwegianBlue, Notorious4life, NuclearWarfare, Nurg, Oahc, Ohnoitsjamie, OllieFury,Omicronpersei8, Onceonthisisland, Onco p53, Osborne, Oxymoron83, Pabbles, Pakaran, Paranomia, Pascal.Tesson, Pb30, Pdcook, Petri Krohn, Pgan002, Pharaoh of the Wizards, PhilipTrueman, Phoebe, Phsource, Piano non troppo, Pill, Pinethicket, Plasticup, Plumbago, Poetaris, Poindexter Propellerhead, Pokemop, Politepunk, PoliticalJunkie, Poppy1128, Pretendo27,Programmer13, Prowikia, Ptenets, Pwhitwor, Qmwne235, Quinsareth, RFerreira, Radiant chains, Radon210, RainbowOfLight, RapidR, Raven1977, Reach Out to the Truth, RexNL,Rhymenoceros, Rich Farmbrough, Rondona12, Ronhjones, Rrburke, Rror, Ryulong, SDC, SabreMau, Sagaciousuk, Sam Hocevar, Samwb123, Sandiegoryu, Santryl, Sarranduin, Satellite9876,Scarian, Schmiddy, Sciurinæ, Seba5618, Shadowjams, ShakingSpirit, Shanes, Sharkamania, Shawn in Montreal, Shirik, Shlomke, Shoeofdeath, Shreshth91, Silence, Sir Nicholas deMimsy-Porpington, Sjakkalle, Skater, SkiRacerPat, Skizzik, Skunkboy74, SmartGuy, Smile a While, Snowmanradio, Snowolf, SoWhy, Soliloquial, Spartan-James, Spencer, Splintercellguy,SpuriousQ, Srose, Staeiou, StaticGull, StefanB sv, Stephenb, Sunja, Sunshine gurl12, Suppyyuppy, Sushilover2000, Sven Manguard, Swiftblade21, TBerlin, THEN WHO WAS PHONE?,Tangerines, Tangotango, Tannin, Taollan82, Tarix of Tajun, Tellyaddict, Template namespace initialisation script, Tempodivalse, Tengo hambre, Tetracube, TexMurphy, TexasAndroid, TheParting Glass, The Thing That Should Not Be, Thebear1221, Thebeginning, Thejerm, Thenudist, Thomas81, Tide rolls, Tlrmet, Tohd8BohaithuGh1, Tom harrison, Tommy2010, Tony Fox,TonyBallioni, Tqaz72, Train2104, TransporterMan, Traxs7, Trevor MacInnis, Twilight Helryx, Twsx, Tyrol5, Tzepish, UWDI ced, Uncle Dick, Uper1111, VX, Valérie75, Vanished user39948282, Vcelloho, Veinor, Versus22, Vina, VirtualDelight, Vsmith, W33v1l, Waggers, Washburnmav, Watch37264, WatermelonPotion, Wavelength, Wayne Slam, Wevets,Wideheadofknowledge, Wifione, Wikieditor06, Wikitrevor, William, Willow177, Wilson44691, Wimt, Winchelsea, Winkleberrycaruthers, Wizardman, Youngsunkimwalker, Zooey.elle., 1647anonymous edits

Image Sources, Licenses and ContributorsImage:World ocean map.gif  Source: http://en.wikipedia.org/w/index.php?title=File:World_ocean_map.gif  License: Public Domain  Contributors: User:QuizimodoImage:Copepodkils.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Copepodkils.jpg  License: GNU Free Documentation License  Contributors: Dbenzhuser, Lycaon, Matanya(usurped)Image:Crown of Thorns-jonhanson.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Crown_of_Thorns-jonhanson.jpg  License: Creative Commons Attribution-Sharealike 2.0 Contributors: jon hanson on flickr.Image:Chelonia mydas and bubbles.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Chelonia_mydas_and_bubbles.jpg  License: Creative Commons Attribution-Sharealike 3.0 Contributors: Mila ZinkovaImage:Sea otters holding hands.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Sea_otters_holding_hands.jpg  License: Creative Commons Attribution 2.0  Contributors: joemessfrom austinImage:Tide pools in santa cruz.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Tide_pools_in_santa_cruz.jpg  License: Creative Commons Attribution-Sharealike 3.0  Contributors:Mila Zinkova

LicenseCreative Commons Attribution-Share Alike 3.0 Unportedhttp:/ / creativecommons. org/ licenses/ by-sa/ 3. 0/