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Quiz

Open Oceans

Genie V 10 Fragen

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  1. 1Ocean basin circulation
    • The major ocean surface ([blank_start]horizont[blank_end]al) currents are driven by two processes: 1) global [blank_start]wind[blank_end] patterns, and 2) [blank_start]latitudinal[blank_end] variation in the [blank_start]Coriolis[blank_end] force.
    • Major global wind patterns are the [blank_start]easter[blank_end]ly flowing trade winds between [blank_start]3[blank_end]0oN and [blank_start]3[blank_end]0oS, [blank_start]wester[blank_end]ly winds between [blank_start]3[blank_end]0-60o, and [blank_start]easter[blank_end]ly polar winds at latitudes >[blank_start]6[blank_end]0o. – these are driven by heating of the earth by the [blank_start]sun[blank_end]
    • In the Ekman Spiral the surface current moves in a direction [blank_start]45[blank_end]o to the right of the wind in the northern hemisphere, and to the [blank_start]left[blank_end] in the southern hemisphere, because of the [blank_start]Coriolis[blank_end] effect. The surface water moves as a [blank_start]thin[blank_end] layer. As it does so, it moves the layer below it at a [blank_start]slower[blank_end] speed, thus producing a spiral down into the water column. Motion normally ceases at [blank_start]1[blank_end]00m depth.
    • The overall average transport of all the layers is a net water movement at [blank_start]9[blank_end]0o to the direction of the wind transport. This is [blank_start]Ekman[blank_end] Transport.
    1. Ahorizont
    2. Bwind
    3. Clatitudinal
    4. DCoriolis
    5. Eeaster
    6. F3
    7. G3
    8. Hwester
    9. I3
    10. Jeaster
    11. K6
    12. Lsun
    13. M45
    14. Nleft
    15. OCoriolis
    16. Pthin
    17. Qslower
    18. R1
    19. S9
    20. TEkman
  2. 2Temperature and salinity
    • Sea surface temperature (SST) [blank_start]increases[blank_end] as you move towards the equatorial region.
    • The wind systems of the two hemispheres merge to form the Intertropical [blank_start]Convergence[blank_end] Zone ([blank_start]ITCZ[blank_end]), the position of which generally corresponds to the zone of [blank_start]highest[blank_end] SST.
    • Extremely vigorous [blank_start]up[blank_end]ward movement of warm moist air produces huge [blank_start]cumulo[blank_end]nim[blank_start]bus[blank_end] clouds and [blank_start]heavy[blank_end] precipitation.
    • At equator there is net [blank_start]precipitation[blank_end], at 30 deg n and s there is net [blank_start]evaporation[blank_end], showing how salinity is influenced by rain in these regions.
    1. Aincreases
    2. BConvergence
    3. CITCZ
    4. Dhighest
    5. Eup
    6. Fcumulo
    7. Gbus
    8. Hheavy
    9. Iprecipitation
    10. Jevaporation
  3. 3Nutrients, chlorophyll and primary production
    • [blank_start]Oligo[blank_end]trophic ecosystems have low nutrients and low productivity.
    • [blank_start]Eu[blank_end]trophic ecosystems have high/excessive nutrient inputs and high productivity.
    • Nitrate shows clear spatial differences in [blank_start]distribution[blank_end]. Mean annual concentrations highest in the [blank_start]southern[blank_end] ocean (25μM) and [blank_start]temp[blank_end]erate and [blank_start]sub[blank_end]-polar N. Atlantic (8μM), and lowest in the sub-tropical [blank_start]gyres[blank_end] (0.5μM).
    • Major source of nitrate in subtropical gyres comes from atmospheric sources (as dissolved [blank_start]inorganic[blank_end] nitrogen), as well as from nitrogen [blank_start]fixation[blank_end] and upward transport from [blank_start]below[blank_end] the [blank_start]eu[blank_end]photic zone.
    • Micronutrient that is derived from the atmosphere is [blank_start]iron[blank_end] via Saharan [blank_start]dust[blank_end]. Iron is required in high amounts by the enzyme [blank_start]nitrogenase[blank_end] in [blank_start]cyano[blank_end]bacteria that [blank_start]fix[blank_end] nitrogen from the atmosphere. – shows importance of dust [blank_start]inputs[blank_end] for ocean biology
    • Spatial distribution of [blank_start]nutrients[blank_end] influences the spatial distribution of surface chlorophyll [blank_start]a[blank_end]. Values range from 0.05 – 0.1mg chl a m-3 in the [blank_start]central[blank_end] gyres, up to 1mg chl a m-3 in the NW [blank_start]African[blank_end] upwelling and subtropical convergences.
    • Equatorial upwelling- wind causes [blank_start]divergence[blank_end] of water, 0.3 – 0.5 mg
    • Vertical structure of temperature, chl a, and primary production in the Atlantic transect from [blank_start]5[blank_end]0oN to 50oS illustrated - the main features to note are
    i) the spatial variability in primary production and
    ii) the vertical distribution of the chlorophyll maximum.
    • The chlorophyll maximum gets [blank_start]deeper[blank_end] in equatorial waters (50-80m), and is deepest in sub-[blank_start]tropical[blank_end] gyres (100-150m). The reasons for this are related to the vertical structure of the [blank_start]water[blank_end] column (mixed surface layer temperature, nutrients), as well as the cellular response to high [blank_start]light[blank_end] levels.
    •
    • Smaller (<[blank_start]2[blank_end]μm) size classes of [blank_start]phyto[blank_end]plankton are important in the sub-[blank_start]tropical[blank_end] gyres and [blank_start]equator[blank_end]ial regions where [blank_start]nutrient[blank_end] levels – in particular new nutrients – are low.
    • As a general rule, [blank_start]large[blank_end] phytoplankton species ([blank_start]dia[blank_end]toms) are characteristic of regions with [blank_start]high[blank_end]er levels of new nutrients, while small phytoplankton species ([blank_start]dino[blank_end]flagellates) are characteristic of regions with increased levels of [blank_start]regenerated[blank_end] nutrients.
    1. AOligo
    2. BEu
    3. Cdistribution
    4. Dsouthern
    5. Etemp
    6. Fsub
    7. Ggyres
    8. Hinorganic
    9. Ifixation
    10. Jbelow
    11. Keu
    12. Liron
    13. Mdust
    14. Nnitrogenase
    15. Ocyano
    16. Pfix
    17. Qinputs
    18. Ra
    19. Snutrients
    20. Tcentral
    21. UAfrican
    22. Vdivergence
    23. W5
    24. Xdeeper
    25. Ytropical
    26. Zlight
    27. AAwater
    28. AB2
    29. ACphyto
    30. ADtropical
    31. AEequator
    32. AFnutrient
    33. AGlarge
    34. AHdia
    35. AIhigh
    36. AJdino
    37. AKregenerated
  4. 4Macro- and meso-scale physical variability of subtropical gyres

    • The North [blank_start]Atlantic[blank_end] subtropical gyre (Sargasso Sea) is bounded by a northward fast-flowing [blank_start]West[blank_end]ern Boundary Current – the [blank_start]Gulf[blank_end] Stream.
    • The warm Gulf Stream ([blank_start]2[blank_end]8oC) flows next to southward [blank_start]cold[blank_end] water Labrador Current ([blank_start]5[blank_end]oC). Meandering flow forms where the 2 currents [blank_start]meet[blank_end]. Packets of water become isolated and break off in the opposing flow = Warm and Cold [blank_start]Core[blank_end] Rings.
    • Rings (~[blank_start]1[blank_end]000km) act as [blank_start]meso[blank_end]cosms with own temperature, [blank_start]nutrient[blank_end] and plankton.
    • Meso-scale eddies ([blank_start]1[blank_end]00km) play important role in [blank_start]prod[blank_end]uctivity, pumping nutrient-[blank_start]rich[blank_end] water up from depth. Stimulate new production, so more [blank_start]dia[blank_end]toms so more [blank_start]meso[blank_end]zooplankton
    • Eddies effect top 100-1[blank_start]5[blank_end]0m of water,
    1. AAtlantic
    2. BWest
    3. CGulf
    4. D2
    5. Ecold
    6. F5
    7. Gmeet
    8. HCore
    9. I1
    10. Jmeso
    11. Knutrient
    12. L1
    13. Mprod
    14. Nrich
    15. Odia
    16. Pmeso
    17. Q5
  5. 5Are subtropical gyres ‘marine deserts’ with low productivity?

    Nutrients and production
    • New nutrients (nitr[blank_start]a[blank_end]te) (NO[blank_start]3[blank_end]) enter euphotic zone from outside the system [blank_start]–[blank_end] the atmosphere, transported up from below the [blank_start]eu[blank_end]photic zone, rivers – support new [blank_start]production[blank_end].
    • Regenerated nutrients (a[blank_start]mmoniu[blank_end]m, urea, D[blank_start]O[blank_end]N) are those recycled [blank_start]within[blank_end] the euphotic zone – produced via excretion/d[blank_start]eat[blank_end]h – support [blank_start]regenerated[blank_end] production.
    • f-ratio = ratio of nitrate (NO[blank_start]3[blank_end]) uptake by phytoplankton to total inorganic (N[blank_start]O[blank_end]3, [blank_start]N[blank_end]O2, N[blank_start]H[blank_end]4) and [blank_start]org[blank_end]anic (urea, D[blank_start]O[blank_end]N) uptake by phytoplankton
    1. A3
    2. Ba
    3. C(allochthonous nutrient),
    4. Deu
    5. Eproduction
    6. Fmmoniu
    7. GO
    8. Hwithin
    9. Ieat
    10. Jregenerated
    11. K3
    12. LO
    13. MN
    14. NH
    15. Oorg
    16. PO
  6. 6Old and new views on subtropical gyre production
    Traditional view (Cushing, 1957) on open ocean productivity is summarised as:
    1. Oceanic [blank_start]deserts[blank_end] – steady-[blank_start]state[blank_end] systems where production and [blank_start]bio[blank_end]mass low;
    2. [blank_start]In[blank_end]efficient ecosystems with low nutrient-[blank_start]limited[blank_end] growth; (Growth rates are low relative to [blank_start]optimum[blank_end] growth rates)
    3. Low f-ratios (0.1): new production is [blank_start]1[blank_end]0% of total production.
    New view (Platt et al., 1999) on open ocean productivity is summarised as:
    1. Dynamic [blank_start]non[blank_end]-steady-state systems where [blank_start]episod[blank_end]ic events ([blank_start]meso[blank_end]scale eddies, [blank_start]atmospher[blank_end]ic deposition) are important for total annual production. e.g., [blank_start]6[blank_end]5% of total annual production can occur in a 2-week period. This is because:
    2. Episodic events (associated with increases in [blank_start]N[blank_end]-fixing species) can increase f-ratios 0.1 to 0.[blank_start]3[blank_end]-0.5, supporting [blank_start]new[blank_end] production of [blank_start]di[blank_end]atoms followed by rapid [blank_start]ex[blank_end]port;
    3. The [blank_start]2[blank_end]-layered vertical structure of the water column is important for annual production;
    • Deep waters- blooms during [blank_start]winter[blank_end] due to mixing and NO3 [blank_start]in[blank_end]puts,
    • Upper waters- blooms during late [blank_start]summer[blank_end] based on N – [blank_start]fixing[blank_end] organisms and [blank_start]eddy[blank_end] events
    4. Both the classic and [blank_start]microbial[blank_end] loop food chains are present, depending on the [blank_start]nutrient[blank_end]-status of the system.
    1. Adeserts
    2. Bstate
    3. Cbio
    4. DIn
    5. Elimited
    6. Foptimum
    7. G1
    8. Hnon
    9. Iepisod
    10. Jmeso
    11. Katmospher
    12. L6
    13. MN
    14. N3
    15. Oex
    16. Pnew
    17. Qdi
    18. R2
    19. Swinter
    20. Tin
    21. Usummer
    22. Vfixing
    23. Weddy
    24. Xmicrobial
    25. Ynutrient
  7. 7The deep subsurface chlorophyll maximum
    • Upper water column has very [blank_start]high[blank_end] light levels but is [blank_start]nutrient[blank_end]-depleted particularly with respect to nitrate. – based on [blank_start]regenerated[blank_end] nutrients (low f-ratio, 0.1-0.[blank_start]3[blank_end]),
    • Chlorophyll levels are [blank_start]low[blank_end] in this upper region of the water column, partly because of the [blank_start]low[blank_end] new nutrients, but also because the amount of chlorophyll per cell is low in response to the [blank_start]high[blank_end] light levels. – [blank_start]Photo[blank_end]inhibition - specialised ‘sun’ flora (low cellular [blank_start]pigmen[blank_end]tation)
    • The chlorophyll is at its maximum just above the [blank_start]nitra[blank_end]cline and [blank_start]1[blank_end]% PAR (photosynthetically active r[blank_start]adiation[blank_end]). Here there are greater [blank_start]nutrients[blank_end] to support growth, and because of the lower light levels, the chlorophyll content per [blank_start]cell[blank_end] is higher.
    • The deeper waters are [blank_start]light[blank_end] limited, [blank_start]nutrient[blank_end] rrich, based on [blank_start]new[blank_end] nutrients – [blank_start]high[blank_end] f-ratio of 0.4 – 0.[blank_start]6[blank_end], specialised ‘shade’ flora, (high [blank_start]cellular[blank_end] pigmentation).
    1. Ahigh
    2. Bnutrient
    3. Cregenerated
    4. Dlow
    5. Elow
    6. Fhigh
    7. GPhoto
    8. Hpigmen
    9. Initra
    10. J1
    11. Kadiation
    12. Lnutrients
    13. Mcell
    14. Nlight
    15. Onutrient
    16. Pnew
    17. Qhigh
    18. R6
    19. S3
    20. Tcellular
  8. 8Autotroph communities and the supply of nutrients
    • Biomass and [blank_start]primary[blank_end] production in sub-tropical gyres dominated by [blank_start]small[blank_end] cells, <2μm – [blank_start]pico[blank_end]plankton - either [blank_start]pro[blank_end]karyotes containing [blank_start]chloro[blank_end]phyll a (e.g. Prochloro[blank_start]coccus[blank_end] marinus (0.6 microm), Syne[blank_start]cho[blank_end]coccus spp (1 microm) or small [blank_start]eu[blank_end]karyotes (e.g.,flagell[blank_start]ates[blank_end], Pico[blank_start]eukaryotic[blank_end] flagellates (0.8 - [blank_start]2[blank_end]μm), [blank_start]dino[blank_end]flagellates, cocco[blank_start]lithophores[blank_end]).
    • 60-[blank_start]9[blank_end]0% chl a biomass & 60-[blank_start]8[blank_end]0% C-fixation due to cells [blank_start]<[blank_end]2μm
    • When conditions are right – fresh supply of [blank_start]new[blank_end] nutrients – then larger species (>[blank_start]2[blank_end]microm) such as diatoms can [blank_start]bloom[blank_end] quickly. – no need for regenerated nutrients
    • A large fraction of the production in sub-[blank_start]tropical[blank_end] gyres is [blank_start]re[blank_end]generated production, supported by [blank_start]re[blank_end]generated nutrients.
    • New nutrients can be obtained either from [blank_start]atmos[blank_end]pheric inputs, through nitrogen-[blank_start]fixation[blank_end] by [blank_start]cyano[blank_end]bacteria such as Tricho[blank_start]desmium[blank_end] or obtained from below the [blank_start]euphotic[blank_end] zone by vertically migrating phytoplankton such as the [blank_start]mat[blank_end]-forming diatom [blank_start]Rhizo[blank_end]solenia, which takes NO3 in at [blank_start]depth[blank_end], returns to sunlit waters for photosynthesis and repeating the process when [blank_start]intra[blank_end]cellular stores are depleted.
    • The cyano[blank_start]bactera[blank_end] Osc[blank_start]illat[blank_end]oria = main Nitrogen fixing bacteria in the [blank_start]Sargasso[blank_end] sea, it vertically migrates between upper and [blank_start]deep[blank_end] waters to ‘mine’ deep inorganic [blank_start]phosphor[blank_end]ous pools.
    60-[blank_start]9[blank_end]0% of Nitrogen required for production can be supplied by nitrogen fixation if system has [blank_start]no[blank_end] other inputs.
    1. Aprimary
    2. Bsmall
    3. Cpico
    4. Dpro
    5. Echloro
    6. Fcoccus
    7. Gcho
    8. Heu
    9. Iates
    10. Jeukaryotic
    11. K2
    12. Ldino
    13. Mlithophores
    14. N9
    15. O8
    16. P<
    17. Qnew
    18. R2
    19. Sbloom
    20. Ttropical
    21. Ure
    22. Vre
    23. Watmos
    24. Xfixation
    25. Ycyano
    26. Zdesmium
    27. AAeuphotic
    28. ABRhizo
    29. ACmat
    30. ADdepth
    31. AEintra
    32. AFbactera
    33. AGillat
    34. AHSargasso
    35. AIdeep
    36. AJphosphor
    37. AK9
    38. ALno
  9. 9Heterotrophs and trophic dynamics
    • Generally [blank_start]6[blank_end] trophic levels in a sub[blank_start]tropical[blank_end] foodweb, with [blank_start]gela[blank_end]tinous species (jellyfish, cteno[blank_start]phores[blank_end], [blank_start]siphono[blank_end]phores) and small [blank_start]pela[blank_end]gic forage fish forming an important inter[blank_start]mediat[blank_end]e level link in the foodweb.
    • The higher trophic levels are [blank_start]more[blank_end] complex than found in temperate waters, with fast-swimming [blank_start]predato[blank_end]rs, marine [blank_start]mammals[blank_end] and [blank_start]surface[blank_end]-feeding birds abundant.
    • There is a much closer coupling between [blank_start]primary[blank_end] production and [blank_start]gra[blank_end]zing in [blank_start]oligo[blank_end]trophic waters - low levels of [blank_start]regener[blank_end]ated production are continuously grazed by [blank_start]zoo[blank_end]plankton.
    • [blank_start]Classic[blank_end] foodweb dominates in regions with high inputs of [blank_start]new[blank_end] nutrients (e.g., coastal and [blank_start]shelf[blank_end] seas, sub[blank_start]tropical[blank_end] convergence zones), has larger [blank_start]phyto[blank_end]plankton species (dia[blank_start]toms[blank_end]) as its main primary producer, and generally has [blank_start]4[blank_end] trophic levels because large zooplankton and fish can feed [blank_start]direc[blank_end]tly on the [blank_start]larg[blank_end]er primary producers. Grazing losses are [blank_start]high[blank_end].
    • Microbial loop [blank_start]food[blank_end]web dominates in regions with [blank_start]low[blank_end] inputs of new nutrients (e.g., sub-tropical [blank_start]gyres[blank_end], [blank_start]equatorial[blank_end] regions), has small (<[blank_start]2[blank_end]μm) [blank_start]pro[blank_end]karyotes (pro[blank_start]chloro[blank_end]phytes) and eu[blank_start]karyotes[blank_end] ([blank_start]dino[blank_end]flagellates, cocco[blank_start]litho[blank_end]phores) as its main [blank_start]primary[blank_end] producers, and generally has [blank_start]6[blank_end] trophic levels.

    • Small heterotrophs are the dominant [blank_start]graz[blank_end]ers, eg [blank_start]hetero[blank_end]trophic flagellates, [blank_start]dino[blank_end]flagrllates and plank[blank_start]tonic[blank_end] ciliates

    • Oceanic [blank_start]zoo[blank_end]plankton – cope[blank_start]pods[blank_end], other larger [blank_start]crust[blank_end]aceans eg [blank_start]ostra[blank_end]cods, eu[blank_start]phau[blank_end]siis, gelatinus eg cteno[blank_start]phores[blank_end], siphono[blank_start]phores[blank_end], salpa, Velella [blank_start]velella[blank_end], chaet[blank_start]ogn[blank_end]ath, pt[blank_start]ero[blank_end]pod, (other [blank_start]gastro[blank_end]pods),
    1. A6
    2. Btropical
    3. Cgela
    4. Dphores
    5. Esiphono
    6. Fpela
    7. Gmediat
    8. Hmore
    9. Ipredato
    10. Jmammals
    11. Ksurface
    12. Lprimary
    13. Mgra
    14. Noligo
    15. Oregener
    16. Pzoo
    17. QClassic
    18. Rnew
    19. Sshelf
    20. Ttropical
    21. Uphyto
    22. Vtoms
    23. W4
    24. Xlarg
    25. Ydirec
    26. Zhigh
    27. AAfood
    28. ABlow
    29. ACgyres
    30. ADequatorial
    31. AE2
    32. AFpro
    33. AGchloro
    34. AHkaryotes
    35. AIdino
    36. AJlitho
    37. AKprimary
    38. AL6
    39. AMgraz
    40. ANhetero
    41. AOdino
    42. APtonic
    43. AQzoo
    44. ARpods
    45. AScrust
    46. ATostra
    47. AUphau
    48. AVphores
    49. AWphores
    50. AXvelella
    51. AYogn
    52. AZero
    53. BAgastro
  10. 10The microbial foodweb
    • Oceans contain a huge reservoir of [blank_start]dissolved[blank_end] organic matter (DOM). A significant flow of material cycles through the [blank_start]small[blank_end]er labile pool and supports an important component of the food web based on [blank_start]bact[blank_end]erial production – the [blank_start]microbial[blank_end] loop.
    • Inputs to the D[blank_start]O[blank_end]M pool come from virtually all components of the marine [blank_start]plan[blank_end]kton – phytoplankton leakage, production of [blank_start]extra[blank_end]cellular polymeric substances, sloppy feeding by [blank_start]zoo[blank_end]plankton, excretion of low mol wt [blank_start]org[blank_end]anic compounds, leakage from [blank_start]faecal[blank_end] pellets.
    • Small [blank_start]hetero[blank_end]trophic [blank_start]z[blank_end]ooflagellates provide an important link transferring bacterial [blank_start]prod[blank_end]uction to the higher trophic [blank_start]levels[blank_end] in the more cl[blank_start]ass[blank_end]ic food chain.
    • Mixotrophy is a [blank_start]common[blank_end] feature amongst the smaller components of the food web.
    • The microbial loop is important for re[blank_start]mineralisa[blank_end]tion and [blank_start]nutri[blank_end]ent cycling. This is highly significant in the [blank_start]open[blank_end] ocean ecosystems where nutrients are often [blank_start]limiting[blank_end].
    1. Adissolved
    2. Bsmall
    3. Cbact
    4. Dmicrobial
    5. EO
    6. Fplan
    7. Gextra
    8. Hzoo
    9. Iorg
    10. Jfaecal
    11. Khetero
    12. Lz
    13. Mprod
    14. Nlevels
    15. Oass
    16. Pcommon
    17. Qmineralisa
    18. Rnutri
    19. Sopen
    20. Tlimiting

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Beschreibung
degree marine ecology Quiz am Open Oceans, erstellt von Genie V am 25/04/2018.
Autor
Genie V
Sprache
English
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