Test
Rocky reefs
Este test tiene tipos de pregunta que se abren en el reproductor de siempre.
Preguntas del test (21)
1Sections of rocky reef kelp ecosystem
Canopy
ØFronds lying on [blank_start]surface[blank_end] or midwater
ØMost [blank_start]light[blank_end]
Ø[blank_start]Most[blank_end] wave action
Understory
Ø[blank_start]Fronds[blank_end] erect or close to [blank_start]bottom[blank_end]
ØLess [blank_start]light[blank_end]
ØLess [blank_start]wave[blank_end] action
Ø[blank_start]Highest[blank_end] diversity of marine life in kelp forest
ØArea of [blank_start]stipes[blank_end]
Algal turf
Ø[blank_start]Short[blank_end] clumps, filaments and encrusting algae
Ø[blank_start]Least[blank_end] light
Ø[blank_start]Little[blank_end] to [blank_start]no[blank_end] wave influence
ØArea of [blank_start]holdfasts[blank_end] of larger kelp, [blank_start]invertebrates[blank_end], And [blank_start]red[blank_end] algae (especially abundant)
Algal community changes with water [blank_start]depth[blank_end]- Asurface
- Blight
- CMost
- DFronds
- Ebottom
- Flight.
- Gwave
- HHighest
- Istipes
- JLeast
- KLittle
- LShort
- Mno
- Nholdfasts
- Oinvertebrates
- Pred
- Qdepth
2What is a rocky reef?
• Hard [blank_start]substrate[blank_end] (rocks)
–various types (e.g. volcanic, sedimentary, etc.) –not [blank_start]living[blank_end] (e.g., not [blank_start]corals[blank_end] or [blank_start]bivalve[blank_end] shells)
• Usually along continental [blank_start]shelves[blank_end]
• Usually in [blank_start]temperate[blank_end] and [blank_start]subtropical[blank_end] areas (but also in [blank_start]tropical[blank_end] areas where corals can’t grow -- e.g., deep or [blank_start]murky[blank_end], or areas where there is high upwelling or where it is colder. eg found in the [blank_start]Galapogos[blank_end], despite it being a [blank_start]tropical[blank_end] area.
• Typically [blank_start]structurally[blank_end] complex (e.g., crevices to hide in)
• Often with [blank_start]algae[blank_end] attached to rocks...
a particular [blank_start]type[blank_end] of rocky reef with algae attached are [blank_start]kelp[blank_end] forests
kelp forests are v extensivein [blank_start]western[blank_end] coasts of [blank_start]s[blank_end] africa and [blank_start]w[blank_end] america- Asubstrate
- Bliving
- Ccorals
- Dbivalve
- Eshelves
- Fsubtropical
- Gtropical
- Htemperate
- Itropical.
- Jmurky
- KGalapogos
- Lstructurally
- Malgae
- Nkelp
- Otype
- Pwestern
- Qs
- Rw
3What is a kelp bed?
• Rocky reefs with [blank_start]macroalgae[blank_end]
–[blank_start]kelp[blank_end] [blank_start]forest[blank_end]: canopy forming kelps reach sea
surface (e.g., [blank_start]Macrocystis[blank_end])- giant [blank_start]pacific[blank_end] kelp, can grow v fast
–kelp [blank_start]bed[blank_end]: [blank_start]shorter[blank_end] kelps don’t reach surface
Kelp forests can refer to any type of [blank_start]brown[blank_end] [blank_start]seaweed[blank_end] that can form a [blank_start]canopy[blank_end]
• Highly [blank_start]productive[blank_end]- lots of carbon fixation
In terms of primary production, kelp forests are the temperate equivalent of [blank_start]coral reefs[blank_end] and the marine temperate version of [blank_start]tropical rain forests[blank_end]
• [blank_start]Additional[blank_end] structural [blank_start]complexity[blank_end] to the rocky reef, eg lots of [blank_start]juvenile[blank_end] fish living in the [blank_start]understory[blank_end]- Amacroalgae
- Bkelp
- Cforest
- DMacrocystis
- Epacific
- Fbed
- Gshorter
- Hbrown
- Iseaweed
- Jcanopy
- Kproductive
- Lcoral reefs
- Mtropical rain forests
- Ncomplexity
- OAdditional
- Pjuvenile
- Qunderstory
4Kelp forests can refer to any type of brown seaweed that can form a canopy
- AVerdadero
- BFalso
5True Kelp (Order Laminariales)
• [blank_start]Large[blank_end], [blank_start]brown[blank_end] [blank_start]sub[blank_end]tidal seaweeds
• Very [blank_start]strong[blank_end] holdfasts to stay attached
• Form [blank_start]dense[blank_end] forests on the [blank_start]west[blank_end] coast of [blank_start]North[blank_end] [blank_start]America[blank_end]
• “[blank_start]Brown[blank_end] algae” indicates the mix of photosynthetic pigments it has- ALarge
- BSmall
- Cbrown
- DRed
- EGreen
- FOrange
- Gsub
- HSupra
- ISuper
- Jstrong
- KWeak
- Ldense
- MSparse
- Nwest
- ONorth
- PNorth.
- QWest
- RAmerica
- SSouth
- TAfrica
- UBrown
- VRed.
- WGreen.
6Kelp is not a foundation species
- AVerdadero
- BFalso
7Kelp is a [blank_start]foundation[blank_end] species
Definition: A species that has a [blank_start]strong[blank_end] role in [blank_start]structuring[blank_end] the ecological community. without it you have a really [blank_start]different[blank_end] ecological community
Ø Can be in [blank_start]any[blank_end] trophic level...primary producers, secondary consumers,
predators...
Ø Sometimes used interchangeably with “[blank_start]keystone[blank_end] species”
[blank_start]sea[blank_end] stars are a [blank_start]keystone[blank_end] species in the [blank_start]intertidal[blank_end] environments, [blank_start]corals[blank_end] are, big dominant [blank_start]predators[blank_end], eg wolves, grizzly in Yellowstone and polar bears,
getting rid of them [blank_start]may[blank_end] lead to a [blank_start]phase[blank_end] shift from one [blank_start]community[blank_end] to another- Afoundation
- Bprimary
- Cstrong
- Dweak
- Eintermediate
- Fstructuring
- Gcontrolling
- Hdeveloping
- Imaintaining
- Jdifferent
- Ksimilar
- Lany
- Mone
- Nkeystone
- Oprimary
- Papex
- Qintertidal
- Rsubtidal
- Scoastal
- Tphase
- Uslow
- Vtimely
- Wecological
- Xcommunity
- Yecosystem
- Zpopulation
- AAmay
- ABmay not
- ACsea
- ADthrowing
- AEkeystone
- AFfoundation
- AGcorals
- AHweeds
- AIrocks
- AJpredators
- AKconsumers
- ALcarnivores
8General kelp and seaweed structure
• Seaweeds [blank_start]do[blank_end] lack ‘true’ leaves, stems, or [blank_start]roots[blank_end]
• Flat [blank_start]blades[blank_end] [blank_start]instead[blank_end] of leaves
- [blank_start]high[blank_end] surface area to volume ratio
– Chlorophyll [blank_start]is[blank_end] concentrated here
– [blank_start]High[blank_end] SA/V to maximize [blank_start]nutrient[blank_end] absorption
• [blank_start]Air[blank_end] filled pneumatocysts allow blades to [blank_start]float close to the surface[blank_end]
– Grape to volleyball sized
– Blades closer to light
• [blank_start]Stipe[blank_end] - strong, [blank_start]flexible[blank_end] link between blades and holdfast
– provides Shock absorption
– [blank_start]is[blank_end] Photosynthetic
• Holdfasts
- [blank_start]are[blank_end] root-like structures
- [blank_start]do[blank_end] keep seaweeds anchored to the [blank_start]bottom[blank_end]
– [blank_start]Unlike[blank_end] true roots, holdfasts [blank_start]don’t[blank_end] absorb nutrients- Ado
- Bdon't
- Croots
- Dflowers
- Eblades
- Fpaddles
- Gstructures
- Hinstead
- Ias well as
- Jhigh
- Klow
- Lis
- Mis very un-
- NHigh
- OLow
- PAverage
- Qnutrient
- ROxygen
- SLight
- TAir
- UWater
- VCO2
- WHydrogen
- XOxygen
- Yfloat close to the surface
- Zbe neutrally buoyant
- AAsink
- ABmaintain their horizontal structure
- ACStipe
- ADStripe
- AEStalk
- AFBlade
- AGPhloem
- AHflexible
- AIridgid
- AJis
- AKis not
- ALare
- AMare not
- ANdo
- AOdont't
- APbottom
- AQrock
- ARalgal turf
- ASUnlike
- ATLike
- AUdon’t
- AVdo
9note- for the half covered one dont include the cyst in the answer
- ABlades
- BHoldfast
- CStipe
- DThallus
10Canopy kelps extend 5-[blank_start]4[blank_end]5 m above the substrate,
[blank_start]stipitate[blank_end] kelps usually extends less than 2 m above the substrat, [blank_start]prostrate[blank_end] kelps often drape the seafloor.
[blank_start]Phylogenetically[blank_end] not close but due to [blank_start]convergent[blank_end] evolution they form the same morphology.- A4
- Bstipitate
- Cprostrate
- DPhylogenetically
- Econvergent
11Life in kelp understory
• Kelp stipes -- tube-forming p[blank_start]olychaetes[blank_end], bry[blank_start]ozoans[blank_end], other [blank_start]sessile[blank_end] organisms
• Surf perches ([blank_start]eat[blank_end] small crustaceans)
• Topsmelt and Blue rockfish (pl[blank_start]ankton[blank_end] feeders)
• Larvae of [blank_start]benthos[blank_end]
- Aolychaetes
- Bozoans
- Csessile
- Deat
- Eankton
- Fbenthic organisms
12 Steller's sea cow (Hydrodamalis gigas)
• Order Sirenia: includes manatees and dugongs
• Up to 10 meters long (~5-10 tonnes), other Sirenians
are much smaller (~4-5 metres in length)
• Grazed almost exclusively on [blank_start]kelp[blank_end] in the [blank_start]canopy[blank_end]
Ø It had no [blank_start]teeth[blank_end], just broad bony pads to chew kelp
lived in kelp [blank_start]forests[blank_end] where [blank_start]predators[blank_end] eg sharks couldn’t go
couldn’t dive down bc so much blubber they were too [blank_start]buoyant[blank_end]
• Range: northern [blank_start]Pacific[blank_end] ocean (Be[blank_start]ring[blank_end] sea)
• During the Pl[blank_start]eisto[blank_end]cene (last [blank_start]inter[blank_end]glacial) it ranged
much further south
• [blank_start]Hunted[blank_end] to extinction ~ 250 years ago, just 30 years
after it was discovered
Ø Each p[blank_start]opulation[blank_end] only produced few offspring per
year, [blank_start]long[blank_end] generation times, and [blank_start]low[blank_end] population growth, making it highly susceptible to extinction.- Akelp
- Bcanopy
- Cteeth
- Dpredators
- Eforests
- Fbuoyant
- GPacific
- Hring
- Iinter
- Jeisto
- KHunted
- Llong
- Mlow
- Nopulation
13Organisms associated with algal turf
• Kelp holdfast -- small invertebrates, b[blank_start]rittle[blank_end] stars, p[blank_start]olychaetes[blank_end], sea u[blank_start]rchins[blank_end], cr[blank_start]abs[blank_end]
• Many species of ad[blank_start]ult[blank_end] rockfishes and kelp bass (herbi[blank_start]vor[blank_end]es)
• She[blank_start]eph[blank_end]ead (eats cr[blank_start]a[blank_end]bs, ur[blank_start]chi[blank_end]ns)
• Abalone (eat l[blank_start]ive[blank_end] kelp, dr[blank_start]ift[blank_end] kelp, and [blank_start]algal[blank_end] turf)- Arittle
- Brchins
- Cabs
- Dolychaetes
- Eult
- Fvor
- Geph
- Ha
- Ichi
- Jive
- Kift
- Lalgal
14 Global distribution of kelp forests
Not found in the [blank_start]tropics[blank_end] because they are too [blank_start]hot[blank_end] and [blank_start]nutrient[blank_end] poor
Not found in [blank_start]Polar[blank_end] systems due to [blank_start]ice[blank_end] scour and l[blank_start]ight[blank_end] limitation
Only found in [blank_start]temperate[blank_end] regions
n temperate regions go from A[blank_start]laska[blank_end] down to B[blank_start]aj[blank_end]a C[blank_start]alifornia[blank_end]
then from starts again in northern P[blank_start]eru[blank_end].
Also found in s A[blank_start]frica[blank_end], A[blank_start]ustrali[blank_end]a, J[blank_start]apan[blank_end], Ch[blank_start]ina[blank_end], up to No[blank_start]rway[blank_end].
What controls the distribution of kelp beds?
• Substrate: require h[blank_start]ard[blank_end] substrates to attach
• [blank_start]Light[blank_end]: They need l[blank_start]ight[blank_end] to p[blank_start]hotosynthesise[blank_end] (so close to the [blank_start]surface[blank_end])
• Nutrients: They need lots of [blank_start]dissolved[blank_end] [blank_start]inor[blank_end]ganic nutrients to support [blank_start]photosynthesis[blank_end]
• This is why kelp beds are limited to the temperate zones, but their distribution can be extended in [blank_start]up[blank_end]welling zones!- Atropics
- Bhot
- Cnutrient
- DPolar
- Eice
- Fight
- Gtemperate
- Hlaska
- Iaj
- Jalifornia
- Keru
- Lfrica
- Mustrali
- Napan
- Oina
- Prway
- Qard
- Rsurface
- SLight
- Tight
- Uhotosynthesise
- Vdissolved
- Winor
- Xphotosynthesis
- Yup
15What causes kelp deforestation?
Remember, Upwellings are s[blank_start]easonal[blank_end], but they also vary among years (e.g. [blank_start]El-Nino[blank_end] events)
Anomalies of physical conditions that push the physiological tolerance of kelps– e.g.
El-[blank_start]Nino[blank_end] events, temperature or s[blank_start]alinity[blank_end] anomalies
El- Niño causes [blank_start]reversal[blank_end] of normal weather patterns, the events are cyc[blank_start]lical[blank_end].
normally off the coast of p[blank_start]eru[blank_end] there is much upwelling of [blank_start]cold[blank_end], nutrient [blank_start]rich[blank_end] water, El Niño brings an intrusion of [blank_start]warm[blank_end] water from the [blank_start]west[blank_end], increasing sea [blank_start]surface[blank_end] temperatures and [blank_start]decreasing[blank_end] nut[blank_start]rient[blank_end] levels.
La [blank_start]Niña[blank_end] reduces temperatures and kelp cover [blank_start]increases[blank_end] during these years.
• Storms (removes k[blank_start]elp[blank_end] and/or sea urchins)
• Sea urchins getting out of control (due to p[blank_start]redators[blank_end], food l[blank_start]imitation[blank_end], etc) (urchins eat d[blank_start]rift[blank_end] kelp, if no d[blank_start]rift[blank_end] kelp they [blank_start]eat[blank_end] the holdfasts)
Sea urchins are h[blank_start]erbivores[blank_end] and potentially destructive to kelp
• Urchins normally pa[blank_start]ssively[blank_end] feed on drift kelp (free-floating k[blank_start]elp[blank_end] detritus)
• When d[blank_start]rift[blank_end] kelp is l[blank_start]imited[blank_end], and urchins start to experience f[blank_start]ood[blank_end] limitation, and their feeding b[blank_start]ehavior[blank_end] changes
Aggregate into a feeding “[blank_start]front[blank_end]”
• Start to feed on l[blank_start]ive[blank_end] kelp holdfasts, rather than d[blank_start]rift[blank_end] kelp.
• Dislodge them from the bed f[blank_start]loor[blank_end]
This can create an urchin [blank_start]barren[blank_end], where Kelp forest has been deforested by urchin grazing. Cru[blank_start]sto[blank_end]se cor[blank_start]alli[blank_end]ne algae replaces all other sea[blank_start]weed[blank_end]s.
In a Kelp forest with low densities of [blank_start]urchins[blank_end]. Mix of kelp and other types of tu[blank_start]rf[blank_end] algae.
Urchin barrens are [blank_start]widespread[blank_end], and can vary in du[blank_start]ration[blank_end]- Aeasonal
- BEl-Nino
- CNino
- Dalinity
- Ereversal
- Flical
- Geru
- Hcold
- Irich
- Jwarm
- Kwest
- Lsurface
- Mdecreasing
- Nrient
- ONiña
- Pincreases
- Qelp
- Rredators
- Simitation
- Trift
- Urift
- Veat
- Werbivores
- Xssively
- Yelp
- Zrift
- AAimited
- ABood
- ACehavior
- ADfront
- AEive
- AFrift
- AGloor
- AHbarren
- AIalli
- AJsto
- AKweed
- ALurchins
- AMrf
- ANwidespread
- AOration
16When urchins get out of control, they initiate a “[blank_start]phase[blank_end] shift” in kelp b[blank_start]ed[blank_end] ecosystems
ØDefinition: When an e[blank_start]cosystem[blank_end] changes from one s[blank_start]table[blank_end] state to another due to per[blank_start]turbation[blank_end]s. In this case, the ecosystem changes from a kelp [blank_start]forest[blank_end] to an urchin [blank_start]barren[blank_end].
• These shifts are [blank_start]widely[blank_end] distributed, are sometimes but not always r[blank_start]eversible[blank_end], and can vary in d[blank_start]uration[blank_end].
General kelp health
• Healthy abundant kelps provide abundant d[blank_start]etritus[blank_end] for urchins, keep them in check
• The wh[blank_start]iplash[blank_end] motion of the kelp will also deter u[blank_start]rchins[blank_end] from entering the kelp [blank_start]forest[blank_end], and will prevent them from at[blank_start]taching[blank_end] to the kelp
• Therefore, any physiological or environmental source of stress for the kelp can pr[blank_start]omote[blank_end] urchins- Aphase
- Bed
- Ctable
- Dcosystem
- Eturbation
- Fforest
- Gbarren
- Hwidely
- Ieversible
- Juration
- Ketritus
- Liplash
- Mrchins
- Nforest
- Otaching
- Pomote
17The sea otter-driven trophic cascade
A [blank_start]chain[blank_end]-reaction within [blank_start]food[blank_end] webs that results from changing p[blank_start]opulation[blank_end] d[blank_start]ensities[blank_end] at higher [blank_start]trophic[blank_end] levels, shifting the d[blank_start]ominance[blank_end] and im[blank_start]pact[blank_end] of co[blank_start]nsumers[blank_end] in lower levels.
Trophic Ecology
Bottom-up vs. Top-down control of c[blank_start]ommunity[blank_end] structure
Bottom up = [blank_start]productivity[blank_end] driven
Top-down = Trophic [blank_start]cascades[blank_end]
predator -> h[blank_start]erbivore[blank_end] -> primary [blank_start]producer[blank_end] (s[blank_start]econd[blank_end] level organism (herbivore) releases the lowest level to proliferate)
e.g., Fish -> [blank_start]Zoo[blank_end]plankton -> [blank_start]Phyto[blank_end]plankton
Effects of trophic cascades are stronger in [blank_start]simple[blank_end] systems (marine) than in [blank_start]complex[blank_end] systems (terrestrial)
Inter[blank_start]annual[blank_end] variability in top [blank_start]predators[blank_end] can induce [blank_start]inter[blank_end]annual differences in otters, urchins and kelps
eg in the Aleutians, [blank_start]Alaska[blank_end], there is a [blank_start]simple[blank_end] food web with intermediate diversity,
Whales eat m[blank_start]ore[blank_end] otters possibly because their other food sources (e.g. [blank_start]seals[blank_end]) are declining
The trophic cascade may also affect coastal [blank_start]bioeros[blank_end]ion rates...- Achain
- Bfood
- Copulation
- Densities
- Etrophic
- Fominance
- Gpact
- Hnsumers
- Iommunity
- Jproductivity
- Kcascades
- Lerbivore
- Mproducer
- Necond
- OZoo
- PPhyto
- Qsimple
- Rcomplex
- Sannual
- Tpredators
- Uinter
- VAlaska
- Wsimple
- Xseals
- Yore
- Zbioeros
18In W[blank_start]estern[blank_end] N[blank_start]orth[blank_end] A[blank_start]tlantic[blank_end], there is a Simple food webs, with very strong interactions.
The p[blank_start]rostrate[blank_end] Laminar kelp, sea urchins and the Atlantic cod. the c[blank_start]oastal[blank_end] cod was hunted to e[blank_start]xtinction[blank_end]. The cod are functionally similar to the sea [blank_start]otters[blank_end].
A bit further North at N[blank_start]ova[blank_end] S[blank_start]cotia[blank_end], there was similar dynamics to Maine in terms of p[blank_start]redator[blank_end] collapse (case of the cod), but there urchin [blank_start]diseas[blank_end]e is also important. [blank_start]disease[blank_end]s can have a v quick effect bc in high population d[blank_start]ensities[blank_end] it spreads f[blank_start]aster[blank_end] therefore v short [blank_start]la[blank_end]g.
Recovery of kelp after [blank_start]urchin[blank_end] disease episode encouraged c[blank_start]rabs[blank_end] to migrate into kelp beds.
These feed on urchin [blank_start]larva[blank_end]e, preventing urchin [blank_start]recruit[blank_end]ment!
Therefore, although we’ve seen many more urchins settle since the return of kelp, almost none of them survive due to crab p[blank_start]redation[blank_end]!
They also feed on diseased a[blank_start]dult[blank_end] urchins.- Aestern
- Borth
- Ctlantic
- Drostrate
- Extinction
- Foastal
- Gotters
- Hova
- Icotia
- Jredator
- Kdiseas
- Ldisease
- Mensities
- Naster
- Ola
- Purchin
- Qrabs
- Rlarva
- Srecruit
- Tredation
- Udult
19IN [blank_start]southern[blank_end] California, [blank_start]High[blank_end] in diversity. [blank_start]Rarely[blank_end] shift to barrens, [blank_start]Otters[blank_end]wereremovedfromC[blank_start]alifornia[blank_end]manyyearsago (between 150-200 years), yet phase shifts were only apparent recently, Manydiversec[blank_start]onsumers[blank_end]includingpredatorsand herbivores that could have f[blank_start]unctional[blank_end]ly replaced ot[blank_start]ters[blank_end] or [blank_start]urchins[blank_end], thereby b[blank_start]ufferin[blank_end]g the ec[blank_start]osystem[blank_end] from change.
• However,we’vesystematicallyremovedmanyofthese commercially valuable consumers such as ab[blank_start]alone[blank_end], s[blank_start]heephea[blank_end]d, [blank_start]spiny[blank_end] lobster etc.
We’re now seeing more [blank_start]urchin[blank_end] barrens in California!
so the main reasons for increasing urchin barrens are:
- [blank_start]El[blank_end]-[blank_start]Niño[blank_end] events (more [blank_start]EL[blank_end] [blank_start]NIño[blank_end]= v important)
- More st[blank_start]orms[blank_end]
- Weak or no [blank_start]upwell[blank_end]ing
- Warmer
- [blank_start]Less[blank_end] nutrients delivered to the coast
- R[blank_start]emoval[blank_end] of large predators
- Release [blank_start]herbivo[blank_end]res from pr[blank_start]edatio[blank_end]n- AHigh
- BRarely
- Csouthern
- DOtters
- Ealifornia
- Fonsumers
- Gunctional
- Hters
- Iurchins
- Jufferin
- Kosystem
- Lalone
- Mheephea
- Nspiny
- Ourchin
- PNiño
- QEl
- REL
- SNIño
- Torms
- Uupwell
- VLess
- Wemoval
- Xherbivo
- Yedatio
20 Continuous vs. discontinuous phase shifts
Continuous (l[blank_start]inea[blank_end]r): path [blank_start]backward[blank_end] is the same as path forward.
F1 and F2 are called [blank_start]tippin[blank_end]g points
D[blank_start]iscontinuous[blank_end] ([blank_start]non[blank_end]-li[blank_start]near[blank_end]): path backward is [blank_start]not[blank_end] the same as path forward.
Discontinuous phase shifts are [blank_start]harder[blank_end] to predict, and [blank_start]harder[blank_end] to reverse[blank_start]![blank_end]
usually happens when theres [blank_start]higher[blank_end] di[blank_start]versity[blank_end]
When do phase shifts reverse?
• Athresholdisthe[blank_start]change[blank_end]inthesystemthatleads to a s[blank_start]hift[blank_end] from one [blank_start]phas[blank_end]e to the other
• Urchin [blank_start]densit[blank_end]y is clearly a threshold for the creation of urchin barren phase
• Is the threshold for reversing it equivalent in magnitude?
– Is reducing urchin density back to its former level enough to switch the system back?
– Not always!
depends upon the [blank_start]ecostem[blank_end] and r[blank_start]egio[blank_end]n in question
Threshold for creating the barren are different than for reversing the barren, bc Feedback processes [blank_start]stabilize[blank_end] phases
Healthy kelps create a lot of processes which l[blank_start]imit[blank_end] urchins;
eg [blank_start]whipla[blank_end]sh decreases urchin grazing,
more kelp= more sp[blank_start]ore[blank_end] production, so more kelp
more kelp= more [blank_start]detrit[blank_end]us so less urchin mi[blank_start]gratio[blank_end]n and less urchin gra[blank_start]zing[blank_end], both of which lead to more kelp, more kelp = greater pr[blank_start]edator[blank_end] abundance, eg more sh[blank_start]epherd[blank_end]s and spiny [blank_start]lobsters[blank_end]
These create [blank_start]positive[blank_end] feedbacks for the [blank_start]kelp[blank_end] bed, and [blank_start]negative[blank_end] feedbacks for the urchin bed
Urchins in barrens create conditions to p[blank_start]romote[blank_end] local urchin re[blank_start]productive[blank_end] success and rec[blank_start]ruitment[blank_end], but that prevent kelp from settling and thriving
eg barren state means less [blank_start]detri[blank_end]tus so [blank_start]greater[blank_end] urchin migration and [blank_start]greater[blank_end] destructive grazing, both of which enhance the [blank_start]barren[blank_end] state.
barren state means lower predator abundance so enforces barren state
Barren state facilitates urchin se[blank_start]ttlem[blank_end]ent and [blank_start]increases[blank_end] urchin fert[blank_start]ilisation[blank_end] rate, both of which increase urchin rec[blank_start]ruitment[blank_end], which facilitates the barren state.
Des[blank_start]tructive[blank_end] gr[blank_start]azing[blank_end] decreases kelp rec[blank_start]ruitment[blank_end] which [blank_start]increases[blank_end] barren state.
very [blank_start]hard[blank_end] to predict- very r[blank_start]egio[blank_end]n and ti[blank_start]min[blank_end]g specific- Ainea
- Bbackward
- Ctippin
- Discontinuous
- Enon
- Fnear
- Gnot
- Hharder
- Iharder
- J!
- Khigher
- Lversity
- Mchange
- Nhift
- Ophas
- Pdensit
- Qecosystem
- Regio
- Sstabilize
- Timit
- Uwhipla
- Vore
- Wdetrit
- Xgratio
- Yzing
- Zedator
- AAeephead
- ABlobsters
- ACkelp
- ADpositive
- AEnegative
- AFromote
- AGproductive
- AHruitment
- AIdetri
- AJgreater
- AKgreater
- ALbarren
- AMttlem
- ANincreases
- AOilisation
- APruitment
- AQazing
- ARtructive
- ASruitment
- ATincreases
- AUhard
- AVmin
- AWegio
21Another species that sea otters prey upon is the Black [blank_start]abalone[blank_end], Haliotis cracherodii, which is also a [blank_start]graz[blank_end]er.
Eats [blank_start]drift[blank_end] kelp
lives down on the algal turf eats kelp as it drifts into shore
• Lives in the l[blank_start]ow[blank_end] [blank_start]inter[blank_end]tidal – s[blank_start]hallow[blank_end] [blank_start]sub[blank_end]tidal,
• Br[blank_start]oadca[blank_end]st spawns ~once a [blank_start]year[blank_end]
• Juveniles reside in rock crevices to hide from
predators (sea-[blank_start]otters[blank_end], sheep[blank_start]head[blank_end])
• Competition for space with sea-[blank_start]urchins[blank_end]
• Can live >30 [blank_start]years[blank_end]
• Harvested by humans >10,000 years
• Withering foot [blank_start]syndrome[blank_end]
• Endangered (as are [blank_start]sea[blank_end]-otters)
Withering syndrome (WS) is a [blank_start]bacteri[blank_end]al infection that has become highly prevalent in populations inhabiting the warmer waters of California, causing local extinctions of this species.
Ø WS discovered in 1985
Ø It is less prevalent in the cooler waters of Central/n[blank_start]orthern[blank_end] California (more [blank_start]up[blank_end]welling)
Ø Infection rate thought to be largely mediated by water [blank_start]temperature[blank_end] ([blank_start]El[blank_end] Niño and climate change)
At sites where abalone are not yet infected with WS, their abundances are [blank_start]negatively[blank_end] affected by predation from sea-otters.
Abalone [blank_start]density[blank_end] is actually higher in areas with high [blank_start]otter[blank_end] density Why?
• High otter density also means [blank_start]lower[blank_end] [blank_start]urchi[blank_end]n density, increasing the
availability of abalone food (k[blank_start]elp[blank_end]!)
• Juvenile abalone appear to make [blank_start]greater[blank_end] use of rock crevices where
otter densities are high.
high re[blank_start]fuge[blank_end] value- so juveniles not eaten by otters as much S
• [blank_start]Positive[blank_end] relationship between abalone density and habitat with high [blank_start]refuge[blank_end] value
• [blank_start]Positive[blank_end] relationship between abalone density and otter [blank_start]density[blank_end]- Aabalone
- Bgraz
- Cdrift
- Dow
- Einter
- Fhallow
- Gsub
- Hoadca
- Iyear
- Jotters
- Khead
- Lurchins
- Myears
- Nsyndrome
- Osea
- Pbacteri
- Qorthern
- Rup
- Stemperature
- TEl
- Unegatively
- Vdensity
- Wotter
- Xlower
- Yurchi
- Zelp
- AAgreater
- ABfuge
- ACPositive
- ADrefuge
- AEPositive
- AFdensity
Información
- Descripción
- degree marine ecology Test sobre Rocky reefs, creado por Genie V el 11/04/2018.
- Autor
- Genie V
- Idioma
- English
- Visitas
- 1
- Etiquetas
- Valoración
- Aún sin valoraciones Valora este test