Utente:Etrusko25/Sandbox 3: differenze tra le versioni

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=== Consumatori di ordine superiore ===

[[File:Schooling fish.jpg|thumb|upright=1.84|Pesci predatori (''[[Siganus vulpinus]]'') valutano le dimensioni dei pesci foraggio che nuotano in [[banco (pesci)|banchi]]]]

; Invertebrati marini

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Per gli ecosistemi pelagici, Legendre e Rassoulzadagan hanno proposto nel 1995 un continuum di percorsi trofici con la catena alimentare erbivora e il [[ciclo microbico]] come elementi finali della rete alimentare.<ref>{{cita pubblicazione | autore1 =Legendre L. | autore2 =Rassoulzadegan F. | anno =1995 | titolo =Plankton and nutrient dynamics in marine waters | rivista =Ophelia | volume =41 | pp =153-172 | doi = | url =https://www.researchgate.net/profile/Fereidoun-Rassoulzadegan/publication/233101643_Plankton_and_nutrient_dynamics_in_marine_waters/links/54007cc60cf2194bc29ae3c8/Plankton-and-nutrient-dynamics-in-marine-waters.pdf | lingua = en}}</ref> Il classico elemento finale della catena alimentare lineare prevede il consumo di fitoplancton più grande da parte dello zooplancton e la successiva predazione dello zooplancton da parte di zooplancton di ancora maggior dimensione o di altri predatori. In una catena alimentare lineare di questo tipo, un predatore può portare a un'elevata biomassa di fitoplancton (in un sistema con fitoplancton, erbivori e predatori) o a una riduzione della biomassa di fitoplancton (in un sistema a quattro livelli). I cambiamenti nell'abbondanza dei predatori possono quindi portare a cascate trofiche.<ref>{{cita pubblicazione | autore1 =Pace M.L., Cole J.J., Carpenter S.R. e Kitchell J.F.| anno = 1999| titolo =Trophic cascades revealed in diverse ecosystems | rivista =Trends in Ecology & Evolution | volume =14 | numero =12 | pp =483 | doi =488 | url =https://www.researchgate.net/publication/222503894_Trophic_cascades_revealed_in_diverse_ecosystems | lingua = en}}.</ref> Il membro finale del ciclo microbico coinvolge non solo il fitoplancton, come risorsa di base, ma anche il [[carbonio organico disciolto]].<ref>{{cita pubblicazione | autore1 = Azam F., Fenchel T., Field J.G., Gray J.S., Meyer-Reil L.A. e Thingstad F.| anno =1983 | titolo =The ecological role of water-column microbes in the sea | rivista = Marine ecology progress series. Oldendorf| volume =10 | numero =3 | pp =257-263 | doi =10.3354/meps010257 | url =https://www.researchgate.net/profile/Tom-Fenchel/publication/304675281_The_ecological_role_of_water-column_microbes_in_the_sea/links/5777e9ed08ae4645d6100f9c/The-ecological-role-of-water-column-microbes-in-the-sea.pdf | lingua = en}}</ref> Il carbonio organico disciolto viene utilizzato dai batteri eterotrofi per la crescita e questi ultimi vengono predati dallo zooplancton più grande. Di conseguenza, il carbonio organico disciolto viene convertito, attraverso un ciclo batteri-microzooplancton, in zooplancton. Questi due processi di trasferimento del carbonio sono collegati a più livelli. Il fitoplancton di piccole dimensioni può essere consumato direttamente dal microzooplancton.<ref name=Middelburg2019 />

Come illustrato nel diagramma, il carbonio organico disciolto (DOC) viene prodotto in diversi modi e da vari organismi, sia dai produttori primari che dai consumatori di carbonio organico. Il rilascio di DOC da parte dei produttori primari avviene in modo passivo per perdita e in modo attivo durante fasi di crescita irregolare in condizioni di limitazione dei nutrienti.<ref>{{cita pubblicazione | autore1 =Anderson T.R. | autore2 =Williams P.J.B.| anno =1998 | titolo =Modelling the seasonal cycle of dissolved organic carbon at station E1 in the English channel | rivista =Estuarine, Coastal and Shelf Science | volume =46 | numero =1 | pp =93-109 | doi =10.1006/ecss.1997.0257 | url =https://www.researchgate.net/publication/248575665_Modelling_the_Seasonal_Cycle_of_Dissolved_Organic_Carbon_at_Station_E_1in_the_English_Channel | lingua = en}}</ref><ref>{{cita pubblicazione | autore1 =Van den Meersche K., Middelburg J.J., Soetaert K., van Rijswijk P., Boschker H.T.S. e Heip C.H.R.| anno =2004 | titolo =Carbon–nitrogen coupling and algal–bacterial interactions during an experimental bloom: modeling a 13C tracer experiment | rivista =Limnology and Oceanography | volume =49 | numero =3 | pp =862-878 | doi =10.2307/3597802 | url =https://aslopubs.onlinelibrary.wiley.com/doi/pdfdirect/10.4319/lo.2004.49.3.0862 | lingua = en}}</ref>. AnotherUn directaltro pathwaypercorso fromdiretto phytoplanktondal tofitoplancton dissolved organical pool involvesdi carbonio organico disciolto coinvolge la [[viral lysislisi]] virale.<ref>{{cita pubblicazione | autore1 =Suttle CAC.A. (| anno =2005) "| titolo =Viruses in the sea". ''| rivista =Nature'', '''| volume =437''': | numero =7057 | pp =356–361| url =https://www.academia.edu/download/40315905/virus_in_the_sea.pdf | lingua = en}}</ref> [[MarineI viruses]]virus aremarini asono majoruna delle principali cause ofdi phytoplanktonmortalità mortalitydel fitoplancton nell'oceano, in theparticolare ocean,nelle particularlyacque inpiù warmer,calde low-latitudee watersa bassa latitudine. [[SloppyL'alimentazione feeding]]incompleta bydegli herbivoreserbivori ande incompletela digestiondigestione ofincompleta preydelle byprede consumersda areparte otherdei sourcesconsumatori ofsono dissolvedaltre organicfonti carbon.di Heterotrophiccarbonio microbesorganico usedisciolto. extracellularI enzymesmicrorganismi toeterotrofi solubilizeutilizzano [[particulateenzimi organicextracellulari carbon]]per anddisciogliere useil thiscarbonio andorganico otherparticolato dissolvede organicutilizzano carbonquesta resourcese foraltre growthrisorse anddi maintenance.carbonio Partorganico ofdisciolto theper microbialla heterotrophiccrescita productione isil usedmantenimento. byParte microzooplankton;della anotherproduzione partmicrobica ofeterotrofa theviene heterotrophicutilizzata communitydal ismicrozooplancton; subjectun'altra toparte intensedella viralcomunità lysiseterotrofa andè thissoggetta causesa releaseun'intensa oflisi dissolvedvirale organicche carbonprovoca again.il Therilascio efficiencydi ofcarbonio theorganico microbialdisciolto. loopL'efficienza dependsdel onciclo multiplemicrobico factorsdipende butda inmolteplici particularfattori, onma thein relativeparticolare importancedall'importanza ofrelativa predationdella andpredazione virale lysisdella tolisi thevirale nella mortalitymortalità ofdei heterotrophicmicrobi microbeseterotrofi.<ref name=Middelburg2019 />

<gallery mode=packed heights=330px style=float:left; caption="Rete trofica pelagica">

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File:Export Processes in the Ocean from Remote Sensing.jpg| Rete alimentare pelagica e pompa biologica. I collegamenti tra la pompa biologica dell'oceano, la rete alimentare pelagica e la possibilità di analizzare questi elementi a distanza da navi, satelliti e veicoli autonomi. Le acque azzurre rappresentano la zona eufotica, mentre quelle blu più scure rappresentano la zona mesopelagica o zona crepuscolare.<ref>{{cita pubblicazione |doi=10.3389/fmars.2016.00022|titolo=Prediction of the Export and Fate of Global Ocean Net Primary Production: The EXPORTS Science Plan|anno=2016|autore1=Siegel D.A.|autore2=Buesseler K.O.|autore3=Behrenfeld M.J.|autore4=Benitez-Nelson C.R.|autore5=Boss E.|autore6=Brzezinski M.A.|autore7=Burd A.|autore8=Carlson C.A.|autore9=d'Asaro E.A.|autore10=Doney S.C.|autore11=Perry M.J.|autore12=Stanley R.H.R.|autore13=Steinberg D.K.|rivista=Frontiers in Marine Science|volume=3}}</ref>

<gallery mode=packed heights=330px style=float:left; caption="Pelagic food web">

File:Export Processes in the Ocean from Remote Sensing.jpg| Pelagic food web and the [[biological pump]]. Links among the ocean's biological pump and pelagic food web and the ability to sample these components remotely from ships, satellites, and autonomous vehicles. Light blue waters are the [[euphotic zone]], while the darker blue waters represent the [[Mesopelagic zone|twilight zone]].<ref>{{cite journal |doi=10.3389/fmars.2016.00022|title=Prediction of the Export and Fate of Global Ocean Net Primary Production: The EXPORTS Science Plan|year=2016|last1=Siegel|first1=David A.|last2=Buesseler|first2=Ken O.|last3=Behrenfeld|first3=Michael J.|last4=Benitez-Nelson|first4=Claudia R.|last5=Boss|first5=Emmanuel|last6=Brzezinski|first6=Mark A.|last7=Burd|first7=Adrian|last8=Carlson|first8=Craig A.|last9=d'Asaro|first9=Eric A.|last10=Doney|first10=Scott C.|last11=Perry|first11=Mary J.|last12=Stanley|first12=Rachel H. R.|last13=Steinberg|first13=Deborah K.|journal=Frontiers in Marine Science|volume=3|doi-access=free}} [[File:CC-BY icon.svg|50px]] Modified text 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>

</gallery>

<gallery mode=packed heights=390px style=float:right; caption="MesopelagicRete foodtrofica webmesopelagica">

File:Mesopelagic species impact on global carbon budget.png|ImpactImpatto ofdelle mesopelagicspecie speciesmesopelagiche onsul thebilancio globalglobale carbondel budgetcarbonio.<ref>{{cita pubblicazione | autore1 =Wang, F., Wu, Y., Chen, Z., Zhang, G., Zhang, J., Zheng, S. and Kattner, G. (| anno =2019) "| titolo =Trophic interactions of mesopelagic fishes in the South China Sea illustrated by stable isotopes and fatty acids". ''| rivista =Frontiers in Marine Science'', '''| volume =5''': | p =522. {{doi| doi =10.3389/fmars.2018.00522 |doi-access url =freehttps://www.researchgate.net/publication/330323140_Trophic_Interactions_of_Mesopelagic_Fishes_in_the_South_China_Sea_Illustrated_by_Stable_Isotopes_and_Fatty_Acids | lingua = en}}.</ref> DVM = diel[[migrazione vertical migrationnictemerale]], NM = animali non-migration migratori.

</gallery>

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<gallery mode=packed heights=180px style=float:right;>

File:Sigmops bathyphilus1.jpg|MesopelagicI [[bristlemouthGonostomatidae]]s maymesopelagici bepotrebbero theessere mosti abundantvertebrati vertebratespiù onabbondanti thedel planetpianeta, thoughanche littlese isse knownne aboutsa themancora poco..<ref name=Tollefson2020 />

File:Bathykorus bouilloni.jpg|Lo [[Gelatinouszooplancton zooplankton|Gelatinous predatorsgelatinoso]] likecome thisquesta [[narcomedusanNarcomedusae|narcomedusa]] consumeconsuma la thepiù greatestvasta diversitygamma ofdi mesopelagicprede preymesopelagiche.

</gallery>

[[File:An in situ perspective of a deep pelagic food web.jpg|thumb|upright=2|right|AnUna ''inprospettiva situ''“in perspectivesitu” ofdi auna deeprete pelagicalimentare foodpelagica webprofonda derivedderivata fromda ROV-basedosservazioni observationsdi ofcomportamento alimentare effettuate feedingcon veicoli telecomandati (ROV), asrappresentata represented byda 20 broadgrandi taxonomicgruppi groupingstassonomici. TheI linkagescollegamenti betweentra predatorpredatori toe preyprede aresono colouredcolorati accordingin tobase predatorall'origine del gruppo groupdi originpredatori, andmentre loopsi indicatecerchi within-groupindicano feedingl'alimentazione all'interno del gruppo. TheLo thicknessspessore ofdelle thelinee lineso ordei edgesbordi connectingche foodcollegano webi componentscomponenti isdella scaledrete toalimentare theè logproporzionale ofal thelogaritmo numberdel ofnumero di osservazioni uniqueuniche di alimentazione effettuate dal ROV feedingtra observationsil across1991 thee yearsil 1991–20162016 betweentra thei twodue groupsgruppi ofdi animalsanimali. TheI differentdiversi groupsgruppi havehanno eightotto colour-codedtipologie typescodificate accordingcon tocolori maindiversi animalin typesbase asalle indicatedprincipali byclassi thedi animali, come indicato legenddalla andlegenda definede heredefinito qui: redrosso, cephalopodscefalopodi; orangearancione, crustaceanscrostacei; lightverde greenchiaro, fishpesci; darkverde greenscuro, medusameduse; purpleviola, siphonophoressifonofori; blueblu, ctenophoresctenofori ande greygrigio, all otheraltri animalsanimali. In thisquesto plotgrafico, thel'asse verticalverticale axisnon doescorrisponde notal correspondlivello to trophic leveltrofico, becausepoiché thisquesta metricmetrica isnon notè readilyfacilmente estimatedstimabile forper alltutti i membersmembri.<ref name=Choy2017 > {{cita pubblicazione | autore1 =Choy, C.A., | autore2 =Haddock, S.H. and| autore3 =Robison, B.H. (| anno =2017) "| titolo =Deep pelagic food web structure as revealed by ''in situ'' feeding observations". ''| rivista =Proceedings of the Royal Society B: Biological Sciences'', '''| volume =284'''(| numero =1868): | p =20172116. {{| doi| =10.1098/rspb.2017.2116}}. [[File:CC-BY icon.svg|50px]] Modifiedurl text was copied from this source, which is available under a [=https://creativecommonswww.researchgate.orgnet/licenses/by/4.0publication/321633126_Deep_pelagic_food_web_structure_as_revealed_by_in_situ_feeding_observations Creative| Commonslingua Attribution= 4.0 International License].en}}</ref>]]

ScientistsGli arescienziati startingstanno toiniziando explorea esplorare in moremodo detailpiù theapprofondito largelyla unknownzona twilightcrepuscolare zonein ofgran theparte sconosciuta della [[mesopelagiczona mesopelagica]], profonda da 200 toa 1,.000 metres deepmetri. ThisQuesto strato layerè isresponsabile responsibledella forrimozione removingdi aboutcirca 4 billionmiliardi tonnesdi oftonnellate carbondi dioxideanidride fromcarbonica the atmospheredall'atmosfera eachogni yearanno. TheLo mesopelagicstrato layermesopelagico isè inhabitedabitato bydalla mostmaggior ofparte the marine fishdella [[Biomass (ecology)|biomassbiomassa]] di pesci marini.<ref name=Tollefson2020>{{cita pubblicazione | autore1 =Tollefson, JeffJ. (27| Februaryanno =2020) [https://www.nature.com/articles/d41586-020-00520-8| titolo =Enter the twilight zone: scientists dive into the oceans' mysterious middle] ''| rivista =Nature News''. {{doi| volume = | numero = | pp = | doi =10.1038/d41586-020-00520-8 | url =https://www.nature.com/articles/d41586-020-00520-8 | lingua = en}}.</ref>

AccordingSecondo touno astudio del 2017 study, le [[narcomedusaeNarcomedusae|narcomeduse]] consumeconsumano thela greatestpiù diversitygrande ofgamma mesopelagicdi preyprede mesopelagiche, followedseguite bydai [[physonectSiphonophora|sifonofori]] [[siphonophorePhysonectae]]s, daglii [[ctenophoreCtenophora|ctenofori]]s ande dai [[cephalopodCephalopoda|cefalopodi]]s. TheL'importanza importancedella of the so-calledcosiddetta "jellyrete webgelatinosa" issta onlycominciando beginningsolo toora bead understoodessere compresa, butma itsembra seemsche medusaemeduse, ctenophoresctenofori ande siphonophoressifonofori canpossano beessere keypredatori predatorschiave innelle deepreti pelagicalimentari foodpelagiche websprofonde, withcon ecologicalun impactsimpatto similarecologico tosimile predatora fishquello anddei squid.pesci Traditionallypredatori gelatinouse predatorsdei werecalamari. thoughtTradizionalmente ineffectuali providerspredatori ofgelatinosi marineerano trophicconsiderati pathways,fornitori butinefficaci theydi appearrisorse totrofiche havemarine, substantialma andsembrano integralavere rolesun inruolo deepsostanziale pelagicnelle foodreti websalimentari pelagiche profonde.<ref name=Choy2017 /> La [[Dielmigrazione vertical migrationnictemerale]], anun importante importantmeccanismo activedi transporttrasporto mechanismattivo, allowsconsente al [[mesozooplanktonmesozooplancton]] todi sequestersequestrare carbonl'anidride dioxidecarbonica fromdall'atmosfera thee atmospheredi assoddisfare wellil asfabbisogno supplydi carboncarbonio needsdi foraltri otherorganismi mesopelagic organismsmesopelagici.<ref>{{cita pubblicazione | autore1 =Kelly, T.B., Davison, P.C., Goericke, R., Landry, M.R., Ohman, M. and Stukel, M.R. (| anno =2019) "| titolo =The importance of mesozooplankton diel vertical migration for sustaining a mesopelagic food web". ''| rivista =Frontiers in Marine Science'', '''| volume =6''': | p =508. {{doi| doi =10.3389/fmars.2019.00508 |doi url =https://www.frontiersin.org/journals/marine-accessscience/articles/10.3389/fmars.2019.00508/pdf | lingua =free en }}.</ref>

AUno studio del 2020 studyha reportedriportato thatche byentro il 2050 globalil warmingriscaldamento couldglobale bepotrebbe spreadingestendersi inagli theabissi deepoceanici oceana sevenuna timesvelocità fastersette thanvolte itsuperiore isa nowquella attuale, evenanche ifse emissionsle ofemissioni greenhousedi gasesgas areserra cutvenissero ridotte. WarmingIl inriscaldamento degli strati [[mesopelagicmesopelagici]] ande deeperpiù layersprofondi couldpotrebbe haveavere majorconseguenze consequencessignificative forsulla thecatena deepalimentare oceandegli foodabissi weboceanici, sincepoiché oceanle speciesspecie willmarine needdovranno tospostarsi moveper tomantenere staytemperature atcompatibili survivalcon temperaturesla sopravvivenza.<ref>[{{cita web|url=https://www.theguardian.com/environment/2020/may/26/climate-change-in-deep-oceans-could-be-seven-times-faster-by-middle-of-century-report-says |titolo=Climate change in deep oceans could be seven times faster by middle of century, report says] ''|sito=The Guardian'', |lingua=en|data=25 May 2020.</ref>}}<ref>{{cita pubblicazione | autore1 =Brito-Morales, I., Schoeman, D.S., Molinos, J.G., Burrows, M.T., Klein, C.J., Arafeh-Dalmau, N., Kaschner, K., Garilao, C., Kesner-Reyes, K. and Richardson, A.J. (| anno =2020) "| titolo =Climate velocity reveals increasing exposure of deep-ocean biodiversity to future warming". ''| rivista =Nature Climate Change'', | volume =10 | numero =6 | pp.1 =576-6.581 {{doi| doi =10.5281/zenodo.3596584}} | url =https://pure.<uhi.ac.uk/ref>files/8269544/Brito_Morales_etal.2020.MainText.pdf | lingua = en}}

* [https://theconversation.com/fish-in-the-twilight-cast-new-light-on-ocean-ecosystem-22987 Fish in the twilight cast new light on ocean ecosystem] ''The Conversation'', 10 February 2014.

* [https://www.nytimes.com/2015/06/30/science/bristlemouth-ocean-deep-sea-cyclothone.html An Ocean Mystery in the Trillions] ''The New York Times'', 29 June 2015.

* Mesopelagic fishes - [[Malaspina Expedition 2010|Malaspina circumnavigation expedition]] of 2010.<ref>Irigoien, X., Klevjer, T.A., Røstad, A., Martinez, U., Boyra, G., Acuña, J.L., Bode, A., Echevarria, F., Gonzalez-Gordillo, J.I., Hernandez-Leon, S. and Agusti, S. (2014) "Large mesopelagic fishes biomass and trophic efficiency in the open ocean". ''Nature communications'', '''5''': 3271. {{doi|10.1038/ncomms4271}}</ref><ref>[https://www.eurekalert.org/pub_releases/2014-02/snrc-fbi020614.php Fish biomass in the ocean is 10 times higher than estimated] ''EurekAlert'', 7 February 2014.</ref>

[[File:Role of micronekton in pelagic food webs.png|thumb|upright=2|left|OceanicRete pelagicalimentare foodpelagica weboceanica showingche energymostra flowil fromflusso micronektondi toenergia topdal micronecton predatorsai predatori apicali. LineLo thicknessspessore isdelle scaledlinee toè theproporzionale proportionalla inpercentuale thenella dietdieta.<ref>{{cita pubblicazione | autore1 =Choy, C.A., Wabnitz, C.C., Weijerman, M., Woodworth-Jefcoats, P.A. and Polovina, J.J. (| anno =2016) "| titolo =Finding the way to the top: how the composition of oceanic mid-trophic micronekton groups determines apex predator biomass in the central North Pacific". ''| rivista =Marine Ecology Progress Series'', '''| volume =549''': 9–25.| pp =9-25 {{doi| doi =10.3354/meps11680 | url =https://www.researchgate.net/publication/296687226_Finding_the_way_to_the_top_How_the_composition_of_oceanic_mid-trophic_micronekton_groups_determines_apex_predator_biomass_in_the_central_North_Pacific | lingua = en}}.</ref>]]

=== Sulla superficie dell'oceano ===

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[[File:Bacteria, sea slicks and satellite remote sensing.webp|thumb|upright=1.8|left|Batteri, chiazze di petrolio e telerilevamento satellitare. I tensioattivi sono in grado di smorzare le onde capillari superficiali dell'oceano e di levigare la superficie del mare. Il telerilevamento satellitare con [[radar ad apertura sintetica]] (SAR) è in grado di rilevare aree con concentrazioni di tensioattivi o chiazze di petrolio, che appaiono come aree scure sulle immagini SAR.<ref name=Kurata2016>{{cita pubblicazione | autore1 =Kurata, N., Vella, K., Hamilton, B., Shivji, M., Soloviev, A., Matt, S., Tartar, A. and Perrie, W. | anno =2016 | titolo =Surfactant-associated bacteria in the near-surface layer of the ocean | rivista =Scientific Reports | volume =6 | numero =1 | pp =1-8 | doi =10.1038/srep19123 | url =https://www.researchgate.net/publication/258783377_Surfactant-Associated_Bacteria_in_the_Near-Surface_Layer_of_the_Ocean | lingua = en |cid=}}]]

L'habitat della superficie oceanica si trova all'interfaccia tra l'oceano e l'atmosfera. Questo habitat, simile a un [[biofilm]] sulla superficie dell'acqua ospita microrganismi che vivono nello strato più superficiale, noti come [[neuston]]. Questa vasta interfaccia che coprono oltre il 70% della superficie globale ospita i principali processi di scambio aria-acqua. I batteri presenti nel microstrato superficiale dell'oceano, il cosiddetto bacterioneuston, sono interessanti per le loro applicazioni pratiche, quali lo scambio aria-mare dei gas serra, la produzione di aerosol marini attivi sul clima e il telerilevamento dell'oceano.<ref name=Kurata2016 /> Di particolare interesse è la produzione e la degradazione dei [[tensioattivo|tensioattivi]] attraverso processi biochimici microbici. Le principali fonti di tensioattivi nell'oceano aperto includono il fitoplancton,<ref>{{cita pubblicazione | autore1 =Ẑutić, V., Ćosović, B., Marčenko, E., Bihari, N. and Kršinić, F. | anno =1981 | titolo =Surfactant production by marine phytoplankton | rivista =Marine Chemistry | volume =10 | numero =6 | pp =505–520 | doi =10.1016/0304-4203(81)90004-9 | url =https://www.researchgate.net/publication/256558091_Surfactant_production_by_marine_phytoplankton | lingua = en |cid=}}</ref> il dilavamento terrestre e le sostanze depositate dall'atmosfera.<ref name=Kurata2016 />

===At the ocean surface===

{{see also|Ocean surface ecosystem|Sea surface microlayer}}

A differenza delle fioriture algali colorate, i batteri associati ai tensioattivi potrebbero non essere visibili nelle immagini a colori dell'oceano. La capacità di rilevare questi batteri “invisibili” associati ai tensioattivi utilizzando il [[radar ad apertura sintetica]] (SAR) offre enormi vantaggi in tutte le condizioni atmosferiche, indipendentemente dalla presenza di nuvole, nebbia o luce diurna. <ref name=Kurata2016 /> Ciò è particolarmente importante in presenza di venti molto forti, poiché sono proprio queste le condizioni in cui si verificano gli scambi di gas aria-mare più intensi e la produzione di aerosol marini. Pertanto, oltre alle immagini satellitari a colori, le immagini satellitari SAR possono fornire ulteriori informazioni sul quadro globale dei processi biofisici al confine tra oceano e atmosfera, sugli scambi di gas serra tra aria e mare e sulla produzione di aerosol marini attivi sul clima.<ref name=Kurata2016 />

[[File:Bacteria, sea slicks and satellite remote sensing.webp|thumb|upright=1.8|left|Bacteria, sea slicks and satellite remote sensing. Surfactants are capable of dampening the short capillary ocean surface waves and smoothing the sea surface. [[Synthetic aperture radar]] (SAR) satellite remote sensing can detect areas with concentrated surfactants or sea slicks, which appear as dark areas on the SAR images.<ref name=Kurata2016>Kurata, N., Vella, K., Hamilton, B., Shivji, M., Soloviev, A., Matt, S., Tartar, A. and Perrie, W. (2016) "Surfactant-associated bacteria in the near-surface layer of the ocean". ''Scientific Reports'', '''6'''(1): 1–8. {{doi|10.1038/srep19123}}. [[File:CC-BY icon.svg|50px]] Modified text 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>]]

=== Sul fondale marino ===

Ocean surface habitats sit at the interface between the ocean and the atmosphere. The [[biofilm|biofilm-like]] habitat at the surface of the ocean harbours surface-dwelling microorganisms, commonly referred to as [[neuston]]. This vast air–water interface sits at the intersection of major air–water exchange processes spanning more than 70% of the global surface area . Bacteria in the surface microlayer of the ocean, the so-called [[bacterioneuston]], are of interest due to practical applications such as air-sea gas exchange of greenhouse gases, production of climate-active marine aerosols, and remote sensing of the ocean.<ref name=Kurata2016 /> Of specific interest is the production and degradation of [[surfactant]]s (surface active materials) via microbial biochemical processes. Major sources of surfactants in the open ocean include phytoplankton,<ref>Ẑutić, V., Ćosović, B., Marčenko, E., Bihari, N. and Kršinić, F. (1981) "Surfactant production by marine phytoplankton". ''Marine Chemistry'', '''10'''(6): 505–520. {{doi|10.1016/0304-4203(81)90004-9}}.</ref> terrestrial runoff, and deposition from the atmosphere.<ref name=Kurata2016 />

Unlike coloured algal blooms, surfactant-associated bacteria may not be visible in ocean colour imagery. Having the ability to detect these "invisible" surfactant-associated bacteria using [[synthetic aperture radar]] has immense benefits in all-weather conditions, regardless of cloud, fog, or daylight.<ref name=Kurata2016 /> This is particularly important in very high winds, because these are the conditions when the most intense air-sea gas exchanges and marine aerosol production take place. Therefore, in addition to colour satellite imagery, SAR satellite imagery may provide additional insights into a global picture of biophysical processes at the boundary between the ocean and atmosphere, air-sea greenhouse gas exchanges and production of climate-active marine aerosols.<ref name=Kurata2016 />

[[File:Hydrothermal Vents and Methane Seeps.jpg|thumb|right|upright=2|Interazioni tra [[infiltrazione fredda|infiltrazioni fredde]] e [[sorgente idrotermale|sorgenti idrotermali]] con gli ecosistemi marini profondi circostanti. L'asse "y" è espresso in metri sopra il fondale su scala logaritmica. DOC: [[carbonio organico disciolto]], POC: [[carbonio organico particolato]], SMS: solfuri massicci deposti sul fondale marino<ref>{{cita pubblicazione | autore1 =Levin LA, Baco AR, Bowden DA, Colaco A, Cordes EE, Cunha MR, Demopoulos AWJ, Gobin J, Grupe BM, Le J, Metaxas A, Netburn AN, Rouse GW, Thurber AR, Tunnicliffe V, Van Dover CL, Vanreusel A and Watling L | anno =2016 | titolo =Hydrothermal Vents and Methane Seeps: Rethinking the Sphere of Influence | rivista =Frontiers in Marine Science | volume =3 | pp =72 | doi =10.3389/fmars.2016.00072 | url =https://www.researchgate.net/publication/303340969_Hydrothermal_Vents_and_Methane_Seeps_Rethinking_the_Sphere_of_Influence | lingua = en |cid=}}</ref>]]

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===At the ocean floor===

[[File:Hydrothermal Vents and Methane Seeps.jpg|thumb|right|upright=2|Seep and vent interactions with surrounding deep-sea ecosystems. The ''y'' axis is meters above bottom on a log scale. DOC: [[dissolved organic carbon]], POC: [[particulate organic carbon]], SMS: [[seafloor massive sulfide]].<ref>Levin LA, Baco AR, Bowden DA, Colaco A, Cordes EE, Cunha MR, Demopoulos AWJ, Gobin J, Grupe BM, Le J, Metaxas A, Netburn AN, Rouse GW, Thurber AR, Tunnicliffe V, Van Dover CL, Vanreusel A and Watling L (2016). "Hydrothermal Vents and Methane Seeps: Rethinking the Sphere of Influence". ''Front. Mar. Sci.'' '''3''':72. {{doi|10.3389/fmars.2016.00072|doi-access=free}}</ref>]]

{{further|Hydrothermal vent microbial communities|Benthic-pelagic coupling}}

Gli habitat del fondale oceanico ([[benthos|bentonici]]) si trovano all'interfaccia tra l'oceano e l'interno della Terra.

Ocean floor ([[benthic]]) habitats sit at the interface between the ocean and the interior of the Earth.

; Seeps and vents

[[File:Guaymas seep and vent ecosystems.png|thumb|upright=2|left| ConceptualDiagramma diagramconcettuale ofdella faunalstruttura communitydella structurecomunità andfaunistica food-webe patternsdei alongmodelli fluid-fluxdi gradientsrete withinalimentare lungo i gradienti di flusso fluido all'interno degli ecosistemi di [[Guaymasinfiltrazione fredda|infiltrazioni fredde]] seepe and[[sorgente ventidrotermale|sorgenti ecosystemsidrotermali]] di [[Guaymas]].<ref>Portail, M., Olu, K., Dubois, S.F., Escobar-Briones, E., Gelinas, Y., Menot, L. and Sarrazin, J. (2016). "Food-web complexity in Guaymas Basin hydrothermal vents and cold seeps". ''PLOS ONE'', '''11'''(9): p.e0162263. {{doi|10.1371/journal.pone.0162263|doi-access=free}}.</ref><ref>Bernardino AF, Levin LA, Thurber AR and Smith CR (2012). "Comparative Composition, Diversity and Trophic Ecology of Sediment Macrofauna at Vents, Seeps and Organic Falls". PLOS ONE, 7(4): e33515. PMID 22496753. {{doi|10.1371/journal.pone.0033515|doi-access=free}}.</ref><ref>Portail M, Olu K, Escobar-Briones E, Caprais JC, Menot L, Waeles M, et al. (2015). "Comparative study of vent and seep macrofaunal communities in the Guaymas Basin". Biogeosciences. 12(18): 5455–79. {{doi|10.5194/bg-12-5455-2015|doi-access=free}}.</ref>]]

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=== Reti trofiche costiere ===

===Coastal webs===

{{see also|Marine coastal ecosystem}}

{{cleanup images|date=February 2023}}

CoastalLe watersacque includecostiere thecomprendono watersle inacque degli [[estuariesestuario|estuari]] ande overquelle sopra la [[continentalpiattaforma shelvescontinentale]]. TheyOccupano occupy aboutcirca l'8% perdella centsuperficie oftotale thedegli total ocean areaoceani.<ref>{{citecita journalpubblicazione |doi = 10.1016/j.margeo.2014.01.011|titletitolo = Geomorphology of the oceans|year anno= 2014|last1autore1 = Harris|first1 = P.T.|last2autore2 = Macmillan-Lawler|first2 = M.|last3autore3 = Rupp|first3 = J.|last4autore4 = Baker|first4 = E.K.|journal rivista= Marine Geology|volume = 352|pagespp = 4–24|bibcode = 2014MGeol.352....4H}}</ref> ande accountrappresentano forcirca aboutla halfmetà ofdella allproduttività theoceanica oceantotale. productivity.I Thenutrienti keychiave nutrientsche determiningdeterminano l'[[eutrophicationeutrofizzazione]] aresono nitrogenl'azoto innelle coastalacque waterscostiere ande phosphorusil infosforo lakesnei laghi. BothEntrambi aresi foundtrovano in highalte concentrationsconcentrazioni innel [[guano]] (seabird feces), whichche actsfunge asda afertilizzante fertilizerper forl'oceano thecircostante surroundingo oceanper orun anlago adjacent lakeadiacente. L'[[Uricacido acidurico]] isè theil dominantcomposto nitrogenazotato compound,dominante e anddurante duringla itssua mineralizationmineralizzazione differentvengono nitrogenprodotti formsvari arecomposti produceddell'azoto.<ref name=Otero2018 />

EcosystemsGli ecosistemi, evenanche thosequelli withcon seeminglylimiti distinctapparentemente bordersdistinti, rarelyraramente functionfunzionano independentlyin ofmodo otherindipendente adjacentdagli systemsaltri sistemi adiacenti.<ref>{{citecita journalpubblicazione |doi = 10.1111/j.0030-1299.2005.13728.x|title titolo= Marine subsidies alter the diet and abundance of insular and coastal lizard populations|yearanno = 2005|last1autore1 = Barrett|first1 = Kyle|last2autore2 = Anderson|first2 = Wendy B.|last3autore3 = Wait|first3 = D. Alexander|last4autore4 = Grismer|first4 = L. Lee|last5autore5 = Polis†|first5 =Polis Gary A.|last6autore6 = Rose†|first6 =Rose Michael D.|journal rivista= Oikos|volume = 109| issuenumero=1 |pages pp= 145–153| bibcode=2005Oikos.109..145B }}</ref> EcologistsGli areecologi increasinglyriconoscono recognizingsempre thepiù importantl'importanza effectsdegli thateffetti cross-ecosystemche transportil oftrasporto energydi andenergia nutrientse havesostanze onnutritive planttra andecosistemi animaldiversi populationsha andsulle popolazioni e communitiessulle comunità vegetali e animali.<ref>{{citecita journalpubblicazione |doi = 10.1086/285858|titletitolo = Linking Marine and Terrestrial Food Webs: Allochthonous Input from the Ocean Supports High Secondary Productivity on Small Islands and Coastal Land Communities|year anno= 1996|last1autore1 = Polis|first1 = Gary A.|last2autore2 = Hurd|first2 = Stephen D.|journalrivista = The American Naturalist|volume = 147|issue numero= 3|pagespp = 396–423|s2cid = 84701185}}</ref><ref>{{citecita journalpubblicazione |issn = 0006-3568|year anno= 2002|volume = 52|page p= 917|titletitolo = Pacific Salmon in Aquatic and Terrestrial Ecosystems|last1autore1 = Gende|first1 = Scott M.|last2autore2 = Edwards|first2 = Richard T.|last3autore3 = Willson|first3 = Mary F.|last4autore4 = Wipfli|first4 = Mark S.|journal rivista= BioScience|issue numero= 10|doi = 10.1641/0006-3568(2002)052[0917:PSIAAT]2.0.CO;2|jstor = 10.1641/0006-3568(2002)052&#91;0917:PSIAAT&#93;2.0.CO;2|doi-access = free}}</ref> AUn wellesempio knownben examplenoto ofdi thisquesto isfenomeno howè seabirdsil concentratemodo marine-derivedin nutrientscui ongli breedinguccelli islandsmarini inconcentrano thei formnutrienti ofdi fecesorigine marina sulle isole dove effettuano la nidificazione sotto forma di feci (guano) whichche containscontengono ≈15–20circa il 15-20% nitrogendi azoto (N), ase well asil 10% phosphorusdi fosforo.<ref name= Gagnon2013>{{citecita journalpubblicazione |doi = 10.1371/journal.pone.0061284|title titolo= Seabird Guano Fertilizes Baltic Sea Littoral Food Webs|year anno= 2013|last1autore1 = Gagnon|first1 = Karine|last2autore2 = Rothäusler|first2 = Eva|last3autore3 = Syrjänen|first3 = Anneli|last4 autore4= Yli-Renko|first4 = Maria|last5autore5 = Jormalainen|first5 = Veijo|journal rivista= PLOS ONE|volume = 8|issue numero= 4|article-numberp = e61284|pmid = 23593452|pmc = 3623859|bibcode = 2013PLoSO...861284G|doi-access = free}}</ref><ref>{{citecita journalpubblicazione |doi = 10.1016/j.atmosenv.2012.02.007|titletitolo = The Great Cormorant (Phalacrocorax carbo) colony as a "hot spot" of nitrous oxide (N2O) emission in central Japan|year anno= 2012|last1autore1 = Mizota|first1 = Chitoshi|last2autore2 = Noborio|first2 = Kosuke|last3autore3 = Mori|first3 = Yoshiaki|journalrivista = Atmospheric Environment|volume = 57|pages pp= 29–34|bibcode = 2012AtmEn..57...29M}}</ref><ref>{{citecita journalpubblicazione |doi = 10.1002/rcm.3739|titletitolo = Stable carbon and nitrogen isotope analysis of avian uric acid|year anno= 2008|last1autore1 = Bird|first1 = Michael I.|last2 autore2= Tait|first2 = Elaine|last3autore3 = Wurster|first3 = Christopher M.|last4autore4 = Furness|first4 = Robert W.|journal rivista= Rapid Communications in Mass Spectrometry|volume = 22|issue numero= 21|pages pp= 3393–3400|pmid = 18837063|bibcode = 2008RCMS...22.3393B}}</ref> TheseQuesti nutrientsnutrienti dramaticallyalterano alterdrasticamente terrestrialil ecosystemfunzionamento functioninge andle dynamicsdinamiche anddell'ecosistema canterrestre supporte increasedpossono primaryfavorire andun aumento secondarydella productivityproduttività primaria e secondaria.<ref name=Caut2012>{{citecita journalpubblicazione |doi = 10.1371/journal.pone.0039125|titletitolo = Seabird Modulations of Isotopic Nitrogen on Islands|yearanno = 2012|last1cognome1 = Caut|first1nome1 = Stéphane|last2cognome2 = Angulo|first2nome2 = Elena|last3cognome3 = Pisanu|first3nome3 = Benoit|last4cognome4 = Ruffino|first4nome4 = Lise|last5cognome5 = Faulquier|first5nome5 = Lucie|last6cognome6 = Lorvelec|first6nome6 = Olivier|last7cognome7 = Chapuis|first7nome7 = Jean-Louis|last8cognome8 = Pascal|first8nome8 = Michel|last9cognome9 = Vidal|first9nome9 = Eric|last10cognome10 = Courchamp|first10nome10 = Franck|journalrivista = PLOS ONE|volume = 7|issuenumero = 6|article-numberp = e39125|pmid = 22723945|pmc = 3377609|bibcode = 2012PLoSO...739125C|doi-access = free}}</ref><ref>{{CiteCita booklibro|url=https://books.google.com/books?id=X9A_YgEACAAJ&q=%22Seabird+islands:+ecology,+invasion,+and+restoration%22|titletitolo = Seabird Islands: Ecology, Invasion, and Restoration|isbn = 978-0-19-973569-3|last1autore1 = Mulder|first1 = Christa P. H.|last2lautore2 = Anderson|first2 = Wendy B.|last3autore3 = Towns|first3 = David R.|last4autore4 = Bellingham|first4 = Peter J.|date anno= 8 September 2011| publishereditore=Oup USA }}</ref> HoweverTuttavia, althoughsebbene manymolti studiesstudi haveabbiano demonstrateddimostrato nitrogenl'arricchimento enrichmentdi ofazoto terrestrialdei componentsmateriali dueterrestri todovuto alla deposizione di guano deposition acrossin variousvari taxonomicgruppi groupstassonomici,<ref name=Caut2012 /><ref>{{citecita journalpubblicazione |doi = 10.1007/s11273-016-9480-4|titletitolo = Effects of nesting waterbirds on nutrient levels in mangroves, Gulf of Fonseca, Honduras|yearanno = 2016|last1cognome1 = McFadden|first1nome1 = Tyler Neal|last2cognome2 = Kauffman|first2nome2 = J. Boone|last3cognome3 = Bhomia|first3nome3 = Rupesh K.|journalrivista = Wetlands Ecology and Management|volume = 24|issuenumero = 2|pagespp = 217–229| bibcode=2016WetEM..24..217M |s2cid = 6021420| url=https://www.cifor.org/knowledge/publication/6000 }}</ref><ref>{{citecita journalpubblicazione |doi = 10.1007/s00300-012-1265-5|titletitolo = Guano deposition and nutrient enrichment in the vicinity of planktivorous and piscivorous seabird colonies in Spitsbergen|yearanno = 2013|last1cognome1 = Zwolicki|first1nome1 = Adrian|last2cognome2 = Zmudczyńska-Skarbek|first2nome2 = Katarzyna Małgorzata|last3cognome3 = Iliszko|first3nome3 = Lech|last4cognome4 = Stempniewicz|first4nome4 = Lech|journalrivista = Polar Biology|volume = 36|issuenumero = 3|pagespp = 363–372|s2cid = 12110520|doi-access = free| bibcode=2013PoBio..36..363Z }}</ref><ref>{{citecita journalpubblicazione |doi = 10.1073/pnas.1502549112|titletitolo = Global nutrient transport in a world of giants|yearanno = 2016|last1cognome1 = Doughty|first1nome1 = Christopher E.|last2cognome2 = Roman|first2nome2 = Joe|last3cognome3 = Faurby|first3nome3 = Søren|last4cognome4 = Wolf|first4nome4 = Adam|last5cognome5 = Haque|first5nome5 = Alifa|last6cognome6 = Bakker|first6nome6 = Elisabeth S.|last7cognome7 = Malhi|first7nome7 = Yadvinder|last8cognome8 = Dunning|first8nome8 = John B.|last9cognome9 = Svenning|first9nome9 = Jens-Christian|journalrivista = Proceedings of the National Academy of Sciences|volume = 113|issuenumero = 4|pagespp = 868–873|pmid = 26504209|pmc = 4743783|bibcode = 2016PNAS..113..868D|doi-access = free}}</ref> onlysolo aper fewalcuni haveè studiedstata itsstudiata retroactionla onretroazione marinesugli ecosystemsecosistemi andmarini moste ofla thesemaggior studiesparte weredi restrictedquesti tostudi si è limitata alle regioni temperate regionse andalle highacque nutrientricche watersdi nutrienti.<ref name=Gagnon2013 /><ref name=Honig2016>{{citecita journalpubblicazione |doi = 10.1007/s00227-015-2808-4|titletitolo = Evidence of seabird guano enrichment on a coral reef in Oahu, Hawaii|yearanno = 2016|last1cognome1 = Honig|first1nome1 = Susanna E.|last2cognome2 = Mahoney|first2nome2 = Brenna|journalrivista = Marine Biology|volume = 163|issuenumero = 2| pagep=22 | bibcode=2016MarBi.163...22H |s2cid = 87850538}}</ref><ref>{{citecita journalpubblicazione |doi = 10.3354/meps08791|titletitolo = Effects of seabird nesting colonies on algae and aquatic invertebrates in coastal waters|yearanno = 2010|last1cognome1 = Kolb|first1nome1 = GS|last2cognome2 = Ekholm|first2nome2 = J.|last3cognome3 = Hambäck|first3nome3 = PA|journalrivista = Marine Ecology Progress Series|volume = 417|pagespp = 287–300|bibcode = 2010MEPS..417..287K|doi-access = free}}</ref><ref>{{citecita journalpubblicazione |doi = 10.1007/s002270050297|titletitolo = Utilization of nitrogen derived from seabird guano by terrestrial and marine plants at St. Paul, Pribilof Islands, Bering Sea, Alaska|yearanno = 1998|last1cognome1 = Wainright|first1nome1 = S. C.|last2cognome2 = Haney|first2nome2 = J. C.|last3cognome3 = Kerr|first3nome3 = C.|last4cognome4 = Golovkin|first4nome4 = A. N.|last5cognome5 = Flint|first5nome5 = M. V.|journalrivista = Marine Biology|volume = 131| issuenumero=1 |pagespp = 63–71| bibcode=1998MarBi.131...63W |s2cid = 83734364}}</ref> InNei the tropicstropici, coralle reefsbarriere cancoralline besi foundtrovano adjacentin toprossimità islandsdi withisole largecon populationsgrandi ofpopolazioni breedingdi seabirds,uccelli andmarini couldnidificanti bee potentiallypotrebbero affectedessere bypotenzialmente localinfluenzate nutrientdall'arricchimento enrichmentlocale duedi tonutrienti thedovuto transportal oftrasporto seabird-deriveddi nutrientssostanze innutritive surroundingdi watersorigine aviaria nelle acque circostanti. StudiesGli onstudi thesull'influenza influence ofdel guano onsugli tropicalecosistemi marinemarini ecosystemstropicali suggestsuggeriscono nitrogenche froml'azoto contenuto nel guano enrichesarricchisca seawaterl'acqua andmarina reefe i produttori primari della primarybarriera producerscorallina.<ref name=Honig2016 /><ref>{{citecita journalpubblicazione |doi = 10.3354/meps124189|titletitolo = Nutrient inputs from seabirds and humans on a populated coral cay|year anno= 1995|last1autore1 = Staunton Smith|first1 = J.|last2autore2 = Johnson|first2 = CR|journalrivista = Marine Ecology Progress Series|volume = 124|pages pp= 189–200|bibcode = 1995MEPS..124..189S|doi-access = free}}</ref><ref name=Lorrain2017 />

ReefI buildingcoralli coralscostruttori havedi essentialbarriere nitrogenhanno needsun and,basso thrivingfabbisogno indi azoto nutrient-poore prosperando nelle acque tropicali povere tropicaldi watersnutrienti<ref>{{CiteCita booklibro|url=https://books.google.com/books?id=DUtaDwAAQBAJ&pg=PA104|titletitolo=Pollution in Tropical Aquatic Systems|isbn=978-1-351-09277-7|last1cognome1=Connell|first1nome1=Des W.|dateanno=4 May 2018|publishereditore=CRC Press }}</ref> wheredove nitrogenl'azoto isè aun majorfattore limitinglimitante nutrientper forla primaryproduttività productivityprimaria,<ref>{{citecita journalpubblicazione |doi = 10.1016/0169-5347(90)90221-X|titletitolo = Coral reef primary productivity. A hierarchy of pattern and process|year anno= 1990|last1autore1 = Hatcher|first1 = Bruce Gordon|journal rivista= Trends in Ecology & Evolution|volume = 5|issue numero= 5|pages pp= 149–155|pmid = 21232343| bibcode=1990TEcoE...5..149H }}</ref> theyhanno havesviluppato developedspecifici specificadattamenti adaptationsper forconservare conservingquesto this elementelemento. TheirIl establishmentloro andinsediamento maintenancee arela partlyloro duesopravvivenza tosono theirin symbiosisparte withdovuti unicellularalla dinoflagellatessimbiosi con dinoflagellati unicellulari, ''[[Symbiodinium]]'' spp. (zooxanthellae[[zooxantelle]]), thatin cangrado takedi upassorbire ande retaintrattenere dissolvedl'azoto inorganicinorganico nitrogendisciolto (ammoniumammonio ande nitratenitrato) from thedalle surroundingacque waterscircostanti.<ref>{{citecita journalpubblicazione |doi = 10.2307/1312147|jstor = 1312147|last1autore1 = Falkowski|first1 = Paul G.|last2autore2 = Dubinsky|first2 = Zvy|last3autore3 = Muscatine|first3 = Leonard|last4autore4 = McCloskey|first4 = Lawrence|titletitolo = Population Control in Symbiotic Corals|journal rivista= BioScience|year anno= 1993|volume = 43|issue numero= 9|pages pp= 606–611}}</ref><ref name=Marubini1996>{{citecita journalpubblicazione |doi = 10.1007/BF00942117|titletitolo = Nitrate increases zooxanthellae population density and reduces skeletogenesis in corals|year anno= 1996|last1autore1 = Marubini|first1 = F.|last2autore2 = Davies|first2 = P. S.|journal rivista= Marine Biology|volume = 127|issue numero= 2|pages pp= 319–328| bibcode=1996MarBi.127..319M |s2cid = 85085823}}</ref><ref>{{cita pubblicazione | autore1 =Muscatine, L. (1990)| anno [http://www.jackckoch.us/assets/muscatine---=1990---elsevier-science-publishing-company---the-role-of-symbiotic-algae-in-carbon-a.pdf "| titolo =The role of symbiotic algae in carbon and energy flux in reef corals"]{{Dead link|date rivista =MayCoral 2024Reefs |bot volume =InternetArchiveBot25 |fix pp =75-attempted87| url =yeshttps://www.researchgate.net/publication/247988809_The_Role_of_Symbiotic_Algae_in_Carbon_and_Energy_Flux_in_Reef_Corals }},| ''Ecosystemlingua World'',= '''25''':en 75–87.}}</ref> TheseLe zooxanthellaezooxantelle canpossono alsoanche recyclericiclare thei animalrifiuti wastesanimali ande subsequentlysuccessivamente transfertrasferirli themnuovamente backal tocorallo theospite coralsotto hostforma asdi amino acidsaminoacidi,<ref>{{citecita journalpubblicazione |doi = 10.1007/BF00336772|titletitolo = Net uptake of dissolved free amino acids by four scleractinian corals|year anno= 1991|last1autore1 = Ferrier|first1 = M. Drew|journal rivista= Coral Reefs|volume = 10|issue numero= 4|pages pp= 183–187|bibcode = 1991CorRe..10..183F|s2cid = 25973061}}</ref> ammoniumammonio or urea.<ref>{{citecita journalpubblicazione |doi = 10.1093/icb/45.4.595|titletitolo = The Symbiotic Anthozoan: A Physiological Chimera between Alga and Animal|year anno= 2005|last1autore1 = Furla|first1 = P.|last2autore2 = Allemand|first2 = D.|last3autore3 = Shick|first3 = J. M.|last4autore4 = Ferrier-Pagès|first4 = C.|last5autore5 = Richier|first5 = S.|last6autore6 = Plantivaux|first6 = A.|last7autore7 = Merle|first7 = P. L.|last8autore8 = Tambutté|first8 = S.|journalrivista = Integrative and Comparative Biology|volume = 45|issue numero= 4|pages pp= 595–604|pmid = 21676806|doi-access = free}}</ref> CoralsI arecoralli alsopossono ableanche toingerire ingestparticelle nitrogen-richdi sedimento ricche di sedimentcomposti particlesazotati<ref>{{citecita journalpubblicazione |doi = 10.1007/s00338-004-0380-3|titletitolo = Particulate matter ingestion and associated nitrogen uptake by four species of scleractinian corals|yearanno = 2004|last1autore1 = Mills|first1 = Matthew M.|last2autore2 = Lipschultz|first2 = Fredric|last3autore3 = Sebens|first3 = Kenneth P.|journal rivista= Coral Reefs|volume = 23|issue numero= 3|pages pp= 311–323|s2cid = 13212636}}</ref><ref>{{citecita journalpubblicazione |doi = 10.1007/s00227-004-1398-3|titletitolo = Ingestion and assimilation of nitrogen from benthic sediments by three species of coral|year anno= 2004|last1autore1 = Mills|first1 = M. M.|last2autore2 = Sebens|first2 = K. P.|journal rivista= Marine Biology|volume = 145|issuenumero = 6|pages pp= 1097–1106| bibcode=2004MarBi.145.1097M |s2cid = 84698653}}</ref> ande planktonplancton.<ref>{{citecita journalpubblicazione |doi = 10.3354/meps282151|title = Importance of a micro-diet for scleractinian corals|yearanno = 2004|last1cognome1 = Houlbrèque|first1nome1 = F.|last2cognome2 = Tambutté|first2nome2 = E.|last3cognome3 = Richard|first3nome3 = C.|last4cognome4 = Ferrier-Pagès|first4nome4 = C.|journalrivista = Marine Ecology Progress Series|volume = 282|pagespp = 151–160|bibcode = 2004MEPS..282..151H|doi-access = free}}</ref><ref>{{citecita journalpubblicazione |doi = 10.1007/s00338-003-0312-7|title = Effect of natural zooplankton feeding on the tissuetnumero and skeletal growth of the scleractinian coral Stylophora pistillata|yearanno = 2003|last1cognome1 = Ferrier-Pagès|first1nome1 = C.|last2cognome2 = Witting|first2nome2 = J.|last3cognome3 = Tambutté|first3nome3 = E.|last4cognome4 = Sebens|first4nome4 = K. P.|journalrivista = Coral Reefs|volume = 22|issuenumero = 3|pagespp = 229–240|s2cid = 44869188}}</ref> CoastalL'eutrofizzazione eutrophicationcostiera ande excessl'eccesso nutrientdi supplynutrienti canpossono haveavere strongun impactsforte onimpatto sui coralscoralli, leadingcausando touna adiminuzione decreasedella increscita skeletal growth,scheletrica.<ref name=Marubini1996 /><ref>{{citecita journalpubblicazione |doi = 10.4319/lo.1999.44.3.0716|titletitolo = Bicarbonate addition promotes coral growth|year = 1999|last1cognome1 = Marubini|first1nome1 = Francesca|last2cognome2 = Thake|first2nome2 = Brenda|journalrivista = Limnology and Oceanography|volume = 44|issuenumero = 3|pagespp = 716–720|bibcode = 1999LimOc..44..716M| s2cid=83654833 |doi-access = free}}</ref><ref>{{citecita journalpubblicazione |doi = 10.3354/ame021203|titletitolo = Enhancement of pico- and nanoplankton growth by coral exudates|year = 2000|last1cognome1 = Ferrier-Pagès|first1nome1 = C.|last2cognome2 = Leclercq|first2nome2 = N.|last3cognome3 = Jaubert|first3nome3 = J.|last4cognome4 = Pelegrí|first4nome4 = SP|journalrivista = Aquatic Microbial Ecology|volume = 21|pagespp = 203–209|doi-access = free}}</ref><ref>{{citecita journalpubblicazione |doi = 10.3354/meps293069|titletitolo = Effect of nutrient enrichment and elevated CO2 partial pressure on growth rate of Atlantic scleractinian coral Acropora cervicornis|year = 2005|last1cognome1 = Renegar|first1nome1 = DA|last2cognome2 = Riegl|first2nome2 = BM|journalrivista = Marine Ecology Progress Series|volume = 293|pagespp = 69–76|bibcode = 2005MEPS..293...69R|doi-access = free}}</ref><ref name=Lorrain2017 />

Il [[DNA barcoding]] può essere utilizzato per ricostruire le strutture delle reti alimentari con una migliore risoluzione tassonomica nei nodi della rete. Questo restituisce un'identificazione più precisa delle specie e una maggiore chiarezza su chi mangia chi. "Il DNA barcoding e le informazioni sul DNA possono consentire nuovi approcci alla costruzione di reti di interazione più ampie e superare alcuni ostacoli al raggiungimento di una dimensione adeguata del campione".<ref name=Roslin2016 />

[[File:Pathways for guano-derived nitrogen to enter marine food webs.webp|thumb|upright=2|left|Pathways for guano-derived nitrogen to enter marine food webs<ref name=Lorrain2017>{{cite journal |doi = 10.1038/s41598-017-03781-y|title = Seabirds supply nitrogen to reef-building corals on remote Pacific islets|year = 2017|last1 = Lorrain|first1 = Anne|last2 = Houlbrèque|first2 = Fanny|last3 = Benzoni|first3 = Francesca|last4 = Barjon|first4 = Lucie|last5 = Tremblay-Boyer|first5 = Laura|last6 = Menkes|first6 = Christophe|last7 = Gillikin|first7 = David P.|last8 = Payri|first8 = Claude|last9 = Jourdan|first9 = Hervé|last10 = Boussarie|first10 = Germain|last11 = Verheyden|first11 = Anouk|last12 = Vidal|first12 = Eric|journal = Scientific Reports|volume = 7|issue = 1|page = 3721|pmid = 28623288|pmc = 5473863|bibcode = 2017NatSR...7.3721L|s2cid = 6539261}} [[File:CC-BY icon.svg|50px]] Modified text 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>]]

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| header = Seabird colonies

| image1 = Seabird ornitheutrophication coupling.png

| caption1 = [[Seabird#Breeding and colonies|Seabird colonies]] are nutrient hot spots, especially, for nitrogen and phosphorus<ref name=Otero2018>Otero, X.L., De La Peña-Lastra, S., Pérez-Alberti, A., Ferreira, T.O. and Huerta-Diaz, M.A. (2018) "Seabird colonies as important global drivers in the nitrogen and phosphorus cycles". ''Nature communications'', '''9'''(1): 1–8. {{doi|10.1038/s41467-017-02446-8}}. Modified text 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>

}}

{{clear}}

In the diagram above on the right: (1) ammonification produces {{NH3}} and NH₄⁺ and (2) nitrification produces NO₃⁻ by NH₄⁺ oxidation. (3) under the alkaline conditions, typical of the seabird feces, the {{NH3}} is rapidly volatilised and transformed to NH₄⁺, (4) which is transported out of the colony, and through wet-deposition exported to distant ecosystems, which are eutrophised. The phosphorus cycle is simpler and has reduced mobility. This element is found in a number of chemical forms in the seabird fecal material, but the most mobile and bioavailable is [[orthophosphate]], (5) which can be [[Leaching (chemistry)|leached]] by subterranean or superficial waters.<ref name=Otero2018 />

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| header = Filter feeding bivalves

| image1 = Nutrient extraction services provided by bivalves.png

| alt1 =

| caption1 = [[Ecosystem services]] provided by [[filter feeding]] bivalves often resident in estuaries, in the form of [[Nutrient cycle|nutrient extraction]] from phytoplankton. [[Blue mussel]]s are used in the example but other bivalves like [[oyster]]s also provide these nutrient extraction services.<ref name=Petersen2019>Petersen, J.K., Holmer, M., Termansen, M. and Hasler, B. (2019) "Nutrient extraction through bivalves". In: Smaal A., Ferreira J., Grant J., Petersen J., Strand Ø. (eds) ''Goods and Services of Marine Bivalves'', pages 179–208. Springer. {{doi|10.1007/978-3-319-96776-9_10}}. {{ISBN|9783319967769}}</ref>

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| header = [[Estuaries]]

| image1 = Food web of the Venice lagoon.png

| alt1 =

| caption1 = Example food web from an [[estuary]], the [[Venice Lagoon]], involving 27 nodes or functional groups. Colors of flows depict different fishing target (artisanal fisheries in blue, and clam fishery in red) and non-target species (for clam harvesting, in green).<ref>Heymans, J.J., Coll, M., Libralato, S., Morissette, L. and Christensen, V. (2014). "Global patterns in ecological indicators of marine food webs: a modelling approach". ''PLOS ONE'', '''9'''(4). doi:10.1371/journal.pone.0095845.</ref><ref>Pranovi, F., Libralato, S., Raicevich, S., Granzotto, A., Pastres, R. and Giovanardi, O. (2003). "Mechanical clam dredging in Venice lagoon: ecosystem effects evaluated with a trophic mass-balance model". ''Marine Biology'', '''143'''(2): 393–403. doi:10.1007/s00227-003-1072-1.</ref>

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| header = Chesapeake waterbird food web

| image1 = Chesapeake Waterbird Food Web.jpg

| caption1 = Generalized food web for some of the major waterbirds that frequent the [[Chesapeake Bay]]. Food sources and habitats of waterbirds are affected by multiple factors, including [[Introduced species|exotic]] and [[invasive species]].<ref>US Geological Survey (USGS). [http://pubs.usgs.gov/circ/circ1316/html/circ1316chap14.html "Chapter 14: Changes in Food and Habitats of Waterbirds." Figure 14.1.] ''Synthesis of U.S. Geological Survey Science for the Chesapeake Bay Ecosystem and Implications for Environmental Management.'' USGS Circular 1316. {{PD-notice}}</ref><ref>Perry, M.C., Osenton, P.C., Wells-Berlin, A.M., and Kidwell, D.M., 2005, Food selection among Atlantic Coast sea ducks in relation to historic food habits, [abs.] in Perry, M.C., Second North American Sea Duck Conference, November 7–11, 2005, Annapolis, Maryland, Program and Abstracts, USGS Patuxent Wildlife Research Center, Maryland, 123 p. (p. 105).</ref>

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| image1 = Réseau trophique en eaux côtières.jpg

| width1 = 188

| caption1 = Typical food web on a continental shelf

| image2 = Atlantic puffin and herring food chain.png

| width2 = 250

| caption2 = Puffin and herring food web<ref>Bowser, A.K., Diamond, A.W. and Addison, J.A. (2013) "From puffins to plankton: a DNA-based analysis of a seabird food chain in the northern Gulf of Maine". ''PLOS ONE'', '''8'''(12): e83152. {{doi|10.1371/journal.pone.0083152|doi-access=free}}</ref>

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| header = [[Coral reef]]

| header_align =

| image1 = Food web reconstruction by DNA barcodes.jpg

| alt1 =

| caption1 = Food web reconstruction by [[DNA barcoding|DNA barcodes]] at the coral reef of [[Moorea]], French Polynesia. Dietary partitioning among three predatory fish species as detected using [[DNA barcoding in diet assessment|metabarcoding dietary analysis]]. The [[taxonomic resolution]] provided by the metabarcoding approach highlights a complex interaction web and demonstrates that levels of trophic partitioning among [[coral reef fishes]] have likely been underestimated.<ref name=Roslin2016>Roslin, T. and Majaneva, S. (2016) "The use of DNA barcodes in food web construction—terrestrial and aquatic ecologists unite!". ''Genome'', '''59'''(9): 603–628. {{doi|10.1139/gen-2015-0229}}.</ref><ref>Leray M, Meyer CP, Mills SC. (2015) "Metabarcoding dietary analysis of coral dwelling predatory fish demonstrates the minor contribution of coral mutualists to their highly partitioned, generalist diet". ''PeerJ'', '''3''': e1047. {{doi|10.7717/peerj.1047|doi-access=free}}.</ref>

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| header = [[Seagrass meadows]]

| image1 = Visualization of an aggregation of seagrass food webs.png

| caption1 = Cumulative visualization of a number of seagrass food webs from different regions and with different eutrophication levels Different coloured dots represent trophic groups from different trophic levels with black  =  primary producers, dark to light grey  =  secondary producers, and the lightest grey being top predators. The grey links represent feeding links.<ref>Coll, M., Schmidt, A., Romanuk, T. and Lotze, H.K. (2011). "Food-web structure of seagrass communities across different spatial scales and human impacts". ''PLOS ONE'', '''6'''(7): e22591. {{doi|10.1371/journal.pone.0022591|doi-access=free}}. [[File:CC-BY icon.svg|50px]] Modified text 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>

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| header = Coral reef diversity

| header_align =

| image1 = Taxonomic phylogram of eukaryotic diversity at Coral Bay in West Australia.png

| alt1 =

| caption1 = Taxonomic phylogram derived from ToL-metabarcoding of eukaryotic diversity around the coral reefs at [[Coral Bay, Western Australia|Coral Bay]] in Australia. Bar graphs indicate the number of families in each phyla, coloured according to kingdom.<ref>Stat, M., Huggett, M.J., Bernasconi, R., DiBattista, J.D., Berry, T.E., Newman, S.J., Harvey, E.S. and Bunce, M. (2017) "Ecosystem biomonitoring with eDNA: metabarcoding across the tree of life in a tropical marine environment". ''Scientific Reports'', '''7'''(1): 1–11. {{doi|10.1038/s41598-017-12501-5}}.</ref>

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| header = Sponge reefs

| image1 = Generalised food web for sponge reefs.jpg

| caption1 = Generalised food web for [[sponge reef]]s<ref name= Archer2020>{{cite journal | last1=Archer | first1=Stephanie K. | last2=Kahn | first2=Amanda S. | last3=Thiess | first3=Mary | last4=Law | first4=Lauren | last5=Leys | first5=Sally P. | last6=Johannessen | first6=Sophia C. | last7=Layman | first7=Craig A. | last8=Burke | first8=Lily | last9=Dunham | first9=Anya | title=Foundation Species Abundance Influences Food Web Topology on Glass Sponge Reefs | journal=Frontiers in Marine Science | publisher=Frontiers Media SA | volume=7 | date=24 September 2020 | issn=2296-7745 | doi=10.3389/fmars.2020.549478| doi-access=free }} [[File:CC-BY icon.svg|50px]] Modified text 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>

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{{clear left}}

[[DNA barcoding]] can be used to construct food web structures with better taxonomic resolution at the web nodes. This provides more specific species identification and greater clarity about exactly who eats whom. "DNA barcodes and DNA information may allow new approaches to the construction of larger interaction webs, and overcome some hurdles to achieving adequate sample size".<ref name=Roslin2016 />

A newly applied method for species identification is [[DNA metabarcoding]]. Species identification via [[Morphology (biology)|morphology]] is relatively difficult and requires a lot of time and expertise.<ref>{{Citation|last1=Lobo|first1=Eduardo A.|title=Diatoms as Bioindicators in Rivers|date=2016|work=River Algae|pages=245–271|editor-last=Necchi JR|editor-first=Orlando|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-319-31984-1_11|isbn=978-3-319-31983-4|last2=Heinrich|first2=Carla Giselda|last3=Schuch|first3=Marilia|last4=Wetzel|first4=Carlos Eduardo|last5=Ector|first5=Luc}}</ref><ref>{{Citation|last1=Stevenson|first1=R. Jan|title=Assessing environmental conditions in rivers and streams with diatoms|date=2010|work=The Diatoms|pages=57–85|editor-last=Smol|editor-first=John P.|edition=2|publisher=Cambridge University Press|doi=10.1017/cbo9780511763175.005|isbn=978-0-511-76317-5|last2=Pan|first2=Yangdong|last3=van Dam|first3=Herman|editor2-last=Stoermer|editor2-first=Eugene F.}}</ref> [[High throughput sequencing]] DNA metabarcoding enables taxonomic assignment and therefore identification for the complete sample regarding the group specific [[Primer (molecular biology)|primers]] chosen for the previous DNA [[Polymerase chain reaction|amplification]].

Riga 321 ⟶ 210:

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===Polar websReti trofiche polari ===

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| header = Polar topographies

| footer = [[File:Pulse of Snow and Sea Ice.ogv|420px]] The annual pulse of ice and snow at the poles

| image1 = Globe showing Antarctic 2.png

| alt1 =

| caption1 = The [[Antarctica]] is a frozen landmass surrounded by oceans

| image2 = Globe showing Arctic 2.png

| alt2 =

| caption2 = The [[Arctic]] is a frozen ocean surrounded by landmasses

}}

ArcticI andsistemi Antarcticmarini marineartici systemse haveantartici veryhanno differentstrutture [[Marinetopografiche topography|topographicaldifferenti structures]]e, anddi asconseguenza, aanche consequencele haveloro veryreti differentalimentari foodpresentano webcaratteristiche structuresmolto diverse.<ref name=IPCC2001>{{cita libro | curatore1=McCarthy, J.J., | curatore2=Canziani, O.F., |curatore3=Leary, N.A.,| curatore4=Dokken, D.J. |curatore5=and White, K.S. (Eds.)| (2001) [https://books.google.com/books?idtitolo=RT7lQ24quc4C&dq=%22the+Arctic+is+a+frozen+ocean+surrounded+by+continental+landmasses+and+open+oceans%2C+whereas+Antarctica+is+a+frozen+continent+surrounded+solely+by+oceans%22&pg=PA807 ''Climate Change 2001: Impacts, Adaptation, and Vulnerability: Contribution of Working Group II to the Third Assessment Report of the Intergovernmental Panel on Climate Change''] Page| 807,anno=2001 | editore=Cambridge University Press|url=https://www.ipcc.ch/site/assets/uploads/2018/03/WGII_TAR_full_report-2.pdf|p=807 {{ISBN|isbn=9780521015004}}</ref> BothSia Arcticla andrete Antarcticalimentare pelagicpelagica foodartica websche havequella characteristicantartica energypresentano flowsflussi controlledenergetici largelycaratteristici bycontrollati ain fewgran keyparte species.da Butpoche therespecie ischiave. noTuttavia, singlenon genericesiste webun'unica rete generale forper eitherentrambe. AlternativeI pathwayspercorsi arealternativi importantsono forimportanti resilienceper andla maintainingresilienza energye flowsil mantenimento dei flussi energetici. HoweverTuttavia, thesequeste morealternative complicatedpiù alternativescomplesse provideforniscono lessun energyflusso flowenergetico tominore upperalle trophic-levelspecie speciesdei livelli trofici superiori. "Food-webLa structurestruttura maydella berete similaralimentare può essere simile in differentregioni regionsdiverse, butma thele individualsingole speciesspecie thatche dominatedominano mid-trophici levelslivelli varytrofici acrossintermedi polarvariano tra le regioni regionspolari".<ref>{{CiteCita journalpubblicazione|doi=10.1098/rspb.2016.1646|titletitolo=Understanding the structure and functioning of polar pelagic ecosystems to predict the impacts of change|yearanno=2016|last1autore1=Murphy|first1= E. J.|last2autore2=Cavanagh|first2= R. D.|last3autore3=Drinkwater|first3= K. F.|last4autore4=Grant|first4= S. M.|last5autore5=Heymans|first5= J. J.|last6autore6=Hofmann|first6= E. E.|last7autore7=Hunt|first7= G. L.|last8autore8=Johnston|first8= N. M.|journalrivista=Proceedings of the Royal Society B: Biological Sciences|volume=283|issuenumero=1844|pmid=27928038|pmc=5204148}}</ref>

[[File:Humpback whale NOAA.jpg|thumb|300px|left|HumpbackMegattera whaledurante strainingla predazione del krill]]

; Artide

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| header = Penguins and polar bears never meet

| image1titolo = KaiserpinguinePolar mitbear Jungen.jpgfood webs

| width1larghezza1 = 275300

| immagine1 = Arctic marine food web.jpg

| alt1 =

| didascalia1 = Traditional arctic marine food web with a focus on [[wikt:macroorganism|macroorganisms]]

| caption1 = The Antarctic has penguins but no polar bears

| image2larghezza2 = Polar Bear 2004-11-15.jpg270

| immagine2 = Arctic marine food web 2.jpg

| width2 = 240

| alt2 =

| didascalia2 = Contemporary arctic marine food web with a greater focus on the role of [[Marine microorganism|microorganisms]]

| caption2 = The Arctic has polar bears but no penguins

}}

La catena alimentare artica è complessa. La riduzione del ghiaccio marino può influire sull'intera catena alimentare, dalle alghe e dal plancton ai pesci e ai mammiferi. Gli effetti dei cambiamenti climatici su una particolare specie possono propagarsi lungo tutta la catena alimentare e influire su una vasta gamma di altri organismi. Il ritiro dei ghiacci marini non solo sta danneggiando le popolazioni di orsi polari riducendo l'estensione del loro habitat primario, ma sta anche avendo un impatto negativo su di essi attraverso gli effetti sulla catena alimentare. La diminuzione della durata e dell'estensione dei ghiacci marini nell'Artico porta a una diminuzione dell'abbondanza delle alghe che prosperano nelle sacche ricche di nutrienti presenti nel ghiaccio. Queste alghe sono consumate dallo zooplancton, che a sua volta è fonte di cibo dal [[Gadus ogac|merluzzo artico]], un'importante risorsa alimentare per molti mammiferi marini, tra cui le foche. Le foche sono predate dagli orsi polari. Pertanto, il declino delle alghe può contribuire al declino delle popolazioni di orsi polari.<ref>{{cita web|url=https://web.archive.org/web/20170708021834/https://archive.epa.gov/epa/climate-impacts/climate-impacts-ecosystems.html#ref2|titolo=Climate Impacts on Ecosystems: Food Web Disruptions|sito=epa.gov|lingua=en|accesso=11 febbraio 2020}}</ref>

{{clear}}

Nel 2020 i ricercatori hanno riferito che le misurazioni effettuate negli ultimi due decenni sulla produzione primaria nell'[[Oceano Artico]] mostrano un aumento di quasi il 60% dovuto alle maggiori concentrazioni di [[fitoplancton]]. Essi ipotizzano che nuovi nutrienti stiano affluendo da altri oceani e suggeriscono che ciò significhi che l'Oceano Artico potrebbe essere in grado di sostenere una produzione di livello trofico più elevato e un'ulteriore [[Fase di fissazione del carbonio|fissazione del carbonio]] in futuro.<ref>{{cita news |titolo=A 'regime shift' is happening in the Arctic Ocean, scientists say |url=https://phys.org/news/2020-07-regime-shift-arctic-ocean-scientists.html |access=16 agosto 2020 |sito=phys.org |lingua=en}}</ref><ref>{{cita pubblicazione |autore1=Lewis K. M. |autore2=Dijken G. L. van |autore3=Arrigo K. R. |titolo=Changes in phytoplankton concentration now drive increased Arctic Ocean primary production |rivista=Science |anno=2020 |volume=369 |numero=6500 |pp=198–202 |doi=10.1126/science.aay8380 |url=https://www.science.org/doi/10.1126/science.aay8380 |accesso=16 agosto 2020 |lingua=en }}</ref>

; Arctic

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| width1 = 300

| image1 = Arctic marine food web.jpg

| alt1 =

| caption1 = Traditional arctic marine food web with a focus on [[wikt:macroorganism|macroorganisms]]

| width2 = 270

| image2 = Arctic marine food web 2.jpg

| alt2 =

| caption2 = Contemporary arctic marine food web with a greater focus on the role of [[Marine microorganism|microorganisms]]

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The Arctic food web is complex. The loss of sea ice can ultimately affect the entire food web, from algae and plankton to fish to mammals. The [[effects of climate change|impact of climate change]] on a particular species can ripple through a food web and affect a wide range of other organisms... Not only is the decline of sea ice impairing polar bear populations by reducing the extent of their primary habitat, it is also negatively impacting them via food web effects. Declines in the duration and extent of sea ice in the Arctic leads to declines in the abundance of ice algae, which thrive in nutrient-rich pockets in the ice. These algae are eaten by zooplankton, which are in turn eaten by Arctic cod, an important food source for many marine mammals, including seals. Seals are eaten by polar bears. Hence, declines in ice algae can contribute to declines in polar bear populations.<ref>[https://web.archive.org/web/20170708021834/https://archive.epa.gov/epa/climate-impacts/climate-impacts-ecosystems.html#ref2 Climate Impacts on Ecosystems: Food Web Disruptions] ''EPA''. Accessed 11 February 2020. {{PD-notice}}</ref>

In 2020 researchers reported that measurements over the last two decades on [[Marine primary production|primary production]] in the [[Arctic Ocean]] show an increase of nearly 60% due to higher concentrations of [[phytoplankton]]. They hypothesize that new nutrients are flowing in from other oceans and suggest this means the Arctic Ocean may be able to support [[trophic level#Overview|higher trophic level production]] and additional [[carbon fixation]] in the future.<ref>{{cite news |title=A 'regime shift' is happening in the Arctic Ocean, scientists say |url=https://phys.org/news/2020-07-regime-shift-arctic-ocean-scientists.html |access-date=16 August 2020 |work=phys.org |language=en}}</ref><ref>{{cite journal |last1=Lewis |first1=K. M. |last2=Dijken |first2=G. L. van |last3=Arrigo |first3=K. R. |title=Changes in phytoplankton concentration now drive increased Arctic Ocean primary production |journal=Science |date=10 July 2020 |volume=369 |issue=6500 |pages=198–202 |doi=10.1126/science.aay8380 |pmid=32647002 |s2cid=220433818 |url=https://www.science.org/doi/10.1126/science.aay8380 |access-date=16 August 2020 |language=en |issn=0036-8075|url-access=subscription }}</ref>

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| caption1 = Pteropod ([[sea angel]])

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[[File:Nuvola apps kaboodle.svg|16px]] [https://www.youtube.com/watch?v=3-40RU3iSkA Pteropods: Swimming snails of the sea]

| image2 = Marinomonas arctica.jpg

| width2 = 172

| caption2 = The bacterium ''[[Marinomonas arctica]]'' grows inside Arctic sea ice at subzero temperatures

| image3 = Noaa-walrus17.jpg

| width3 = 259

| caption3 = [[Walrus]] are keystone species in the Arctic but are not found in the Antarctic.

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| headertitolo = ArcticRete foodalimentare webartica withcon mixotrophymixotrofia

| image1immagine1 = Arctic food web with mixotrophy.png

| alt1 =

| caption1didascalia1 = YellowFrecce arrowsgialle: flowflusso ofdi energyenergia fromdal thesole sunagli toorganismi photosynthetic organismsfotosintetici ([[autotrophautotrofia|autotrofi]]s ande [[mixotrophmixotrofia|mixotrofi]]s)<br />GrayFrecce arrowsgrigie: flowflusso ofdi carboncarbonio toagli heterotrophseterotrofi<br />GreenFrecce arrowsverdi: majorprincipali pathwaysvie ofdi carbonflusso flowdi tocarbonio orverso fromo mixotrophsdai mixotrofi<br />HCIL: ciliati [[heterotrophiceterotrofi]] ciliates; MCIL: mixotrophicciliati ciliatesmixotrofi; HNF: heterotrophicnanoflagellati nanoflagellateseterotrofi; DOC: dissolvedcarbonio organicorganico carbondisciolto; HDIN: heterotrophicdinoflagellati dinoflagellateseterotrofi<ref>{{cita pubblicazione | autore1 =Stoecker, D.K. and| autore2 =Lavrentyev, P.J. (| anno =2018). "| titolo =Mixotrophic plankton in the polar seas: a pan-arctic review". ''| rivista =Frontiers in Marine Science'', '''| volume =5''': | p =292. {{doi| doi =10.3389/fmars.2018.00292 |doi url =https://www.frontiersin.org/journals/marine-accessscience/articles/10.3389/fmars.2018.00292/pdf | lingua = en |cid=free}}.</ref>

}}

[[File:Pennate diatom infected with two chytrid-like fungal pathogens.png|thumb|upright=1.7|left| [[PennateBacillariophyceae!Diatomea diatompennata]] fromproveniente anda Arcticuno [[meltpond]stagno di fusione] artico, infectedinfettata withda due agenti patogeni twofungini [[Chytridiomycota|chytrid-likechitridiomicotici]] [zoo-]sporangiumcon fungalzoosporangi pathogensrossastri (in false-colourfalsi redcolori). Scale barScala = 10 μm.<ref>{{citecita journalpubblicazione |doi = 10.1038/s42003-020-0891-7|titletitolo = Chytrid fungi distribution and co-occurrence with diatoms correlate with sea ice melt in the Arctic Ocean|year anno= 2020|last1autore1 = Kilias|first1 = Estelle S.|last2autore2 = Junges|first2 = Leandro|last3autore3 = Šupraha|first3 = Luka|last4autore4 = Leonard|first4 = Guy|last5autore5 = Metfies|first5 = Katja|last6autore6 = Richards|first6 = Thomas A.|journal rivista= Communications Biology|volume = 3|issue numero= 1|pagep = 183|pmid = 32317738|pmc = 7174370|s2cid = 216033140}} [[File:CC-BY icon.svg|50px]] Modified text 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>]]

; Antartide

{{clear left}}

; Antarctic

<gallery mode=packed style="float:left;">

File:Ice planet and antarctic jellyfish (crop).jpg|AntarcticMedusa jellyfishantartica ''[[Diplulmaris antarctica]] '' undersotto theil iceghiaccio

File:Phaeocystis.png|Colonies of theColonie dell'alga ''[[Phaeocystis|Phaeocystis antarctica]]'', anun importante componente del importantfitoplancton phytoplankterdel ofMare thedi Ross Seache thatdomina dominatesle earlyfioriture seasondi bloomsinizio afterstagione thedopo seail iceritiro retreatsdei andghiacci exportsmarini significanted carbonesporta una quantità significativa di carbonio.<ref>{{CiteCita journalpubblicazione|doi = 10.5194/bg-15-4923-2018|titletitolo = Colony formation in ''Phaeocystis antarctica'': Connecting molecular mechanisms with iron biogeochemistry|yearanno = 2018|last1autore1 = Bender|first1 = Sara J.|last2autore2 = Moran|first2 = Dawn M.|last3autore3 = McIlvin|first3 = Matthew R.|last4autore4 = Zheng|first4 = Hong|last5autore5 = McCrow|first5 = John P.|last6autore6 = Badger|first6 = Jonathan|last7autore7 = Ditullio|first7 = Giacomo R.|last8autore8 = Allen|first8 = Andrew E.|last9autore9 = Saito|first9 = Mak A.|journalrivista = Biogeosciences|volume = 15|issuenumero = 16|pagespp = 4923–4942| bibcode=2018BGeo...15.4923B |s2cid = 92529531 | doi-access=free }}</ref>

File:Fragilariopsis kerguelensis.jpg| TheLa [[pennate diatom]]diatomea ''[[Fragilariopsis kerguelensis]]'', foundpresente throughoutin thetutta la [[Antarcticcorrente Circumpolarcircumpolare Currentantartica]], isè aun keyfattore driverchiave ofdel theciclo globaldel [[Silicasilicio cycle#Marine silica cycling|silicate pump]]globale.<ref>{{CiteCita journalpubblicazione|doi = 10.1002/ece3.1138|titletitolo = Potential effects of climate change on the distribution range of the main silicate sinker of the Southern Ocean|yearanno = 2014|last1autore1 = Pinkernell|first1 = Stefan|last2autore2 = Beszteri|first2 = Bánk|journalrivista = Ecology and Evolution|volume = 4|issuenumero = 16|pagespp = 3147–3161|pmid = 25473469|pmc = 4222203| bibcode=2014EcoEv...4.3147P }}</ref>

File:Killer Whales Hunting a Crabeater Seal.jpg|AUn groupgruppo ofdi [[killerorche whale]]stenta attemptdi tocacciare dislodge auna [[crabeaterLobodon sealcarcinophagus|foca mangiagranchi]] onsu anun [[icelastrone floe]]di ghiaccio

</gallery>

{{immagine multipla

{{multiple image

| alignallineamento = left

| directiondirezione = horizontal

| widthlarghezza = 400

| headertitolo = ImportanceImportanza of Antarcticdel krill inantartico nei biogeochemicalcicli cyclesbiogeochimici

| image1immagine1 = Importance of Antarctic krill in biogeochemical cycles.png

| didascalia1 = Processi nella [[pompa biologica]]. I numeri indicati sono flussi di carbonio (Gt C yr−1) nelle caselle bianche e quantità di carbonio (Gt C) nelle caselle scure.

| caption1 = Processes in the [[biological pump]]. Numbers given are carbon fluxes (Gt C yr−1) in white boxes and carbon masses (Gt C) in dark boxes.

PhytoplanktonIl convertfitoplancton converte la CO₂, whichche hassi dissolvedè fromdisciolta thedall'atmosfera atmospherenella intoparte thesuperficiale surfacedell'oceano oceansin intocarbonio particulateorganico organic carbonparticolato (POC) duringdurante primaryla productionproduzione primaria. PhytoplanktonIl arefitoplancton thenviene consumedpoi byconsumato dal krill ande smalldai zooplanktonpiccoli grazersorganismi erbivori dello zooplancton, whichche ina loro volta turnsono arepreda preyeddi uponconsumatori bydei higherlivelli trophictrofici levelssuperiori. AnyIl unconsumedfitoplancton phytoplanktonnon formconsumato aggregates,forma andaggregati alongche, withinsieme zooplanktonalle faecalfeci pelletsdello zooplancton, sinkaffondano rapidlyrapidamente anded areescono exporteddallo outstrato of the mixeddi layermescolamento. KrillIl krill, zooplanktonlo andzooplancton microbese intercepti phytoplanktonmicrorganismi inintercettano theil surfacefitoplancton oceansulla andsuperficie sinkingoceanica detritale particlesle atparticelle depthdetritiche in affondamento in profondità, consumingconsumando e trasformando andper respiringrespirazione thisquesto POC toin CO2CO₂ (dissolvedcarbonio inorganicinorganico carbondisciolto, DIC), suchin thatmodo onlytale ache smallsolo proportionuna ofpiccola surface-producedparte carbondel sinkscarbonio toprodotto thein deepsuperficie oceanaffonda nell'oceano profondo (i.e.,cioè a profondità depths > 1000 m 1000 m). AsMentre il krill ande smallerlo zooplanktonzooplancton feed,più theypiccolo alsosi physicallynutrono fragmentframmentando particlesfisicamente intole small,particelle slower-in parti più piccole che oraffondano più lentamente o non-sinking piecesaffondano affatto (viaattraverso sloppyun'alimentazione feedingincompleta, coprorhexydetta ifcoproressi fragmentingse faecesriguarda particelle fecali), retardingritardando POCl'esportazione exportdel POC. ThisQuesto releasesrilascia dissolvedcarbonio organicorganico carbondisciolto (DOC) eitherdirettamente directlydalle fromcellule cellso orindirettamente indirectlyattraverso viala bacterialsolubilizzazione solubilisationbatterica (yellowcerchio circlegiallo aroundintorno al DOC). BacteriaI canbatteri thenpossono remineralisequindi therimineralizzare il DOC toin DIC (CO₂, microbial gardening). Diel vertically migratingIl krill, smallerlo zooplanktonzooplancton andpiù fishpiccolo cane activelyi transportpesci carbonche tomigrano depthverticalmente bydurante consumingil POCgiorno possono trasportare attivamente il carbonio in theprofondità surfaceconsumando layeril atPOC night,nello andstrato metabolisingsuperficiale itdurante atla theirnotte daytimee metabolizzandolo durante il giorno, mesopelagicalle residenceprofondità mesopelagiche in depthscui risiedono. DependingA onseconda speciesdel lifeciclo history,vitale activedelle transportspecie, mayil occurtrasporto onattivo apuò avvenire seasonalanche basissu asbase wellstagionale.<ref>{{citecita journalpubblicazione |doi=10.1038/s41467-019-12668-7 |titletitolo=The importance of Antarctic krill in biogeochemical cycles |yearanno=2019 |last1autore1=Cavan |first1=E. L. |last2autore2=Belcher |first2=A. |last3autore3=Atkinson |first3=A. |last4autore4=Hill |first4=S. L. |last5autore5=Kawaguchi |first5=S. |last6autore6=McCormack |first6=S. |last7autore7=Meyer |first7=B. |last8autore8=Nicol |first8=S. |last9autore9=Ratnarajah |first9=L. |last10autore10=Schmidt |first10=K. |last11autore11=Steinberg |first11=D. K. |last12autore12=Tarling |first12=G. A. |last13autore13=Boyd |first13=P. W. |journalrivista=Nature Communications |volume=10 |issuenumero=1 |pagep=4742 |pmid=31628346 |pmc=6800442 |bibcode=2019NatCo..10.4742C }}. [[File:CC-BY icon.svg|50px]] Modified text 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>

}}

==== Microorganismi polari ====

[[File:Antarctic marine food web - Potter Cove.png|thumb|upright=1.6|right|Antarctic marine food web. Potter Cove 2018. Vertical position indicates trophic level and node widths are proportional to total degree (in and out). Node colors represent functional groups.<ref name=Cordone2018>{{Cite journal|doi = 10.7717/peerj.5531|title = Effects of macroalgae loss in an Antarctic marine food web: Applying extinction thresholds to food web studies|year = 2018|last1 = Cordone|first1 = Georgina|last2 = Marina|first2 = Tomás I.|last3 = Salinas|first3 = Vanesa|last4 = Doyle|first4 = Santiago R.|last5 = Saravia|first5 = Leonardo A.|last6 = Momo|first6 = Fernando R.|journal = PeerJ|volume = 6|article-number = e5531|pmid = 30225167|pmc = 6139014 | doi-access=free }}</ref><ref>{{Cite journal|doi = 10.1016/j.ecss.2017.10.015|title = The Food Web of Potter Cove (Antarctica): Complexity, structure and function|year = 2018|last1 = Marina|first1 = Tomás I.|last2 = Salinas|first2 = Vanesa|last3 = Cordone|first3 = Georgina|last4 = Campana|first4 = Gabriela|last5 = Moreira|first5 = Eugenia|last6 = Deregibus|first6 = Dolores|last7 = Torre|first7 = Luciana|last8 = Sahade|first8 = Ricardo|last9 = Tatián|first9 = Marcos|last10 = Barrera Oro|first10 = Esteban|last11 = De Troch|first11 = Marleen|last12 = Doyle|first12 = Santiago|last13 = Quartino|first13 = María Liliana|last14 = Saravia|first14 = Leonardo A.|last15 = Momo|first15 = Fernando R.|journal = Estuarine, Coastal and Shelf Science|volume = 200|pages = 141–151| bibcode=2018ECSS..200..141M | hdl=11336/39918 |hdl-access = free}}</ref>]]

Nonostante il clima estremamente freddo, le regioni acquatiche polari sono ricche di vita microbica. Anche nelle regioni subglaciali la vita unicellulare si è adattata a questi ambienti estremi. Poiché il pascolo da parte della [[macrofauna]] è limitato nella maggior parte di queste regioni polari, i virus vengono ritenuti importanti agenti di mortalità, influenzando così il ciclo biogeochimico dei nutrienti che, a sua volta, influisce sulle dinamiche della comunità su scala stagionale e spaziale.<ref name=Tau2019>{{cita pubblicazione |doi = 10.3390/v11020189|titolo = Viruses of Polar Aquatic Environments|anno = 2019|autore1 = Yau Sheree|autore2 = Seth-Pasricha Mansha|rivista= Viruses|volume = 11|numero= 2|p= 189}}</ref>

[[File:Common-enemy graph of food web.png|thumb|upright=1.6|right|Common-enemy graph of Antarctic food web. Potter Cove 2018. Nodes represent basal species and links indirect interactions (shared predators). Node and link widths are proportional to number of shared predators. Node colors represent functional groups.<ref name=Cordone2018 />]]

{{clear}}

[[File:Sea ice food web and the microbial loop.png|thumb|upright=1.6|right|Sea ice food web and the microbial loop.<ref>{{Cite journal|doi=10.3390/biology1030542|doi-access=free|title=Recent Advances and Future Perspectives in Microbial Phototrophy in Antarctic Sea Ice|year=2012|last1=Koh|first1=Eileen Y.|last2=Martin|first2=Andrew R.|last3=McMinn|first3=Andrew|last4=Ryan|first4=Ken G.|journal=Biology|volume=1|issue=3|pages=542–556|pmid=24832507|pmc=4009807}}</ref><ref>

* {{cite journal |jstor=24814647|title=The Ecological Role of Water-Column Microbes in the Sea|last1=Azam|first1=F.|last2=Fenchel|first2=T.|last3=Field|first3=J. G.|last4=Gray|first4=J. S.|last5=Meyer-Reil|first5=L. A.|last6=Thingstad|first6=F.|journal=Marine Ecology Progress Series|year=1983|volume=10|issue=3|pages=257–263|doi=10.3354/meps010257|bibcode=1983MEPS...10..257A |doi-access=free}}

* {{cite journal |doi=10.1016/j.jembe.2008.07.013|title=The microbial loop – 25 years later|year=2008|last1=Fenchel|first1=Tom|journal=Journal of Experimental Marine Biology and Ecology|volume=366|issue=1–2|pages=99–103|bibcode=2008JEMBE.366...99F }}

</ref> AAnP = aerobic anaerobic phototroph, DOC = dissolved organic carbon, DOM = dissolved organic matter, POC = particulate organic carbon, PR = proteorhodopsins.]]

{{clear left}}

====Polar microorganisms====

In addition to the varied topographies and in spite of an extremely cold climate, polar aquatic regions are teeming with [[Marine microorganism|microbial life]]. Even in sub-glacial regions, cellular life has adapted to these extreme environments where perhaps there are traces of early microbes on Earth. As grazing by [[macrofauna]] is limited in most of these polar regions, viruses are being recognised for their role as important agents of mortality, thereby influencing the [[Marine biogeochemical cycle|biogeochemical cycling]] of [[Nutrient cycle|nutrients]] that, in turn, impact community dynamics at seasonal and spatial scales.<ref name=Tau2019>{{cite journal |doi = 10.3390/v11020189|doi-access = free|title = Viruses of Polar Aquatic Environments|year = 2019|last1 = Yau|first1 = Sheree|last2 = Seth-Pasricha|first2 = Mansha|journal = Viruses|volume = 11|issue = 2|page = 189|pmid = 30813316|pmc = 6410135}} [[File:CC-BY icon.svg|50px]] Modified text 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>

Microorganisms are at the heart of Arctic and Antarctic food webs. These polar environments contain a diverse range of [[Marine bacteria|bacterial]], [[Marine archaea|archaeal]], and [[Marine protist|eukaryotic]] microbial communities that, along with [[Marine viruses|viruses]], are important components of the polar ecosystems.<ref name= Boetius2015>{{cite journal |doi = 10.1038/nrmicro3522|title = Microbial ecology of the cryosphere: Sea ice and glacial habitats|year = 2015|last1 = Boetius|first1 = Antje|last2 = Anesio|first2 = Alexandre M.|last3 = Deming|first3 = Jody W.|last4 = Mikucki|first4 = Jill A.|last5 = Rapp|first5 = Josephine Z.|journal = Nature Reviews Microbiology|volume = 13|issue = 11|pages = 677–690|pmid = 26344407|s2cid = 20798336}}</ref><ref>{{cite journal |doi = 10.3390/biology3010081|pmc=4009764 |doi-access = free|title = Polar Microbiology: Recent Advances and Future Perspectives|year = 2014|last1 = Rampelotto|first1 = Pabulo|journal = Biology|volume = 3|issue=1 |pages = 81–84}}</ref><ref name="Laybourn-Parry,2009">{{cite journal |doi = 10.1126/science.1173645|title = No Place Too Cold|year = 2009|last1 = Laybourn-Parry|first1 = Johanna|journal = Science|volume = 324|issue = 5934|pages = 1521–1522|pmid = 19541982|bibcode = 2009Sci...324.1521L|s2cid = 33598792}}</ref> They are found in a range of habitats, including [[subglacial lake]]s and [[cryoconite|cryoconite holes]], making the cold biomes of these polar regions replete with metabolically diverse microorganisms and sites of active biogeochemical cycling.<ref>{{cite journal |doi = 10.1038/nrmicro3549|title = Microbial ecology of Antarctic aquatic systems|year = 2015|last1 = Cavicchioli|first1 = Ricardo|journal = Nature Reviews Microbiology|volume = 13|issue = 11|pages = 691–706|pmid = 26456925| hdl=1959.4/unsworks_49930 |s2cid = 23089203|hdl-access = free}}</ref><ref name=Anesio2011>{{cite journal |doi = 10.1016/j.tim.2010.11.002|title = Are low temperature habitats hot spots of microbial evolution driven by viruses?|year = 2011|last1 = Anesio|first1 = Alexandre M.|last2 = Bellas|first2 = Christopher M.|journal = Trends in Microbiology|volume = 19|issue = 2|pages = 52–57|pmid = 21130655}}</ref><ref name= Anesio2012>{{cite journal |doi = 10.1016/j.tree.2011.09.012|title = Glaciers and ice sheets as a biome|year = 2012|last1 = Anesio|first1 = Alexandre M.|last2 = Laybourn-Parry|first2 = Johanna|journal = Trends in Ecology & Evolution|volume = 27|issue = 4|pages = 219–225|pmid = 22000675| bibcode=2012TEcoE..27..219A }}</ref> These environments, that cover approximately one-fifth of the surface of the Earth and that are inhospitable to human life, are home to unique microbial communities.<ref name= Boetius2015 /><ref name= Anesio2012 /><ref name= Ghiglione2012>{{cite journal |doi = 10.1073/pnas.1208160109|title = Pole-to-pole biogeography of surface and deep marine bacterial communities|year = 2012|last1 = Ghiglione|first1 = J.-F.|last2 = Galand|first2 = P. E.|last3 = Pommier|first3 = T.|last4 = Pedros-Alio|first4 = C.|last5 = Maas|first5 = E. W.|last6 = Bakker|first6 = K.|last7 = Bertilson|first7 = S.|last8 = Kirchman|first8 = D. L.|last9 = Lovejoy|first9 = C.|last10 = Yager|first10 = P. L.|last11 = Murray|first11 = A. E.|journal = Proceedings of the National Academy of Sciences|volume = 109|issue = 43|pages = 17633–17638|pmid = 23045668|pmc = 3491513|bibcode = 2012PNAS..10917633G|doi-access = free}}</ref> The resident microbiota of the two regions has a similarity of only about 30%—not necessarily surprising given the limited connectivity of the polar oceans and the difference in freshwater supply, coming from [[glacial melting|glacial melts]] and rivers that drain into the Southern Ocean and the Arctic Ocean, respectively.<ref name= Ghiglione2012 /> The separation is not just by distance: Antarctica is surrounded by the Southern Ocean that is driven by the strong [[Antarctic Circumpolar Current]], whereas the Arctic is ringed by landmasses. Such different topographies resulted as the two continents moved to the opposite polar regions of the planet ≈40–25 million years ago. Magnetic and gravity data point to the evolution of the Arctic, driven by the [[Amerasian]] and [[Eurasian]] basins, from 145 to 161 million years ago to a cold polar region of water and ice surrounded by land.<ref>{{cite journal |doi = 10.1130/0091-7613(1974)2<377:PTMFTE>2.0.CO;2|issn = 0091-7613|year = 1974|volume = 2|page = 377|title = Plate Tectonics Model for the Evolution of the Arctic|last1 = Herron|first1 = Ellen M.|last2 = Dewey|first2 = John F.|last3 = Pitman|first3 = W. C.|journal = Geology|issue = 8|bibcode = 1974Geo.....2..377H}}</ref><ref>{{cite journal |doi = 10.1007/s10712-013-9254-y|title = 4D Arctic: A Glimpse into the Structure and Evolution of the Arctic in the Light of New Geophysical Maps, Plate Tectonics and Tomographic Models|year = 2014|last1 = Gaina|first1 = Carmen|last2 = Medvedev|first2 = Sergei|last3 = Torsvik|first3 = Trond H.|last4 = Koulakov|first4 = Ivan|last5 = Werner|first5 = Stephanie C.|journal = Surveys in Geophysics|volume = 35|issue = 5|pages = 1095–1122|pmid = 26069354|pmc = 4456077|bibcode = 2014SGeo...35.1095G}}</ref><ref>{{cite journal |doi = 10.1016/j.gsf.2014.11.002|title = Seismicity, structure and tectonics in the Arctic region|year = 2015|last1 = Kanao|first1 = Masaki|last2 = Suvorov|first2 = Vladimir D.|last3 = Toda|first3 = Shigeru|last4 = Tsuboi|first4 = Seiji|journal = Geoscience Frontiers|volume = 6|issue = 5|pages = 665–677| s2cid=129578736 |doi-access = free| bibcode=2015GeoFr...6..665K }}</ref> Antarctica was formed from the breakup of the super-continent, [[Gondwana]], a landmass surrounded by the Southern Ocean.<ref name= Boetius2015 /><ref>Adie, R.J. (1962) "The geology of Antarctica". In" ''Antarctic Research: The Matthew Fontaine Maury Memorial Symposium'', John Wiley & Sons.</ref> The Antarctic continent is permanently covered with [[glacial ice]], with only 0.4% of its area comprising exposed land dotted with lakes and ponds.<ref name=Tau2019 />