Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

biol 321 > 311 final > Flashcards

311 final Flashcards

1
Q

what are phytoplankton adapting to?

A

light, nutrient availability, grazing pressures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what phytoplankton have shells and what are they made of?

A

diatoms - silica

coccolithophores - calcium carbonate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are advantages and disadvantages of having shells?

A

disadvantages:

  • energetically costly
  • sinking - takes them out of euphotic zone

advantages:

  • protection from grazing (predators always choose prey with no shells over shelled)
  • buoyancy control - some sinking allows for increased nutrient uptake bc refreshes water around it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what mechanisms are used to prevent sinking

A
  1. change shell thickness
  2. gas vacuole
  3. flagella for swimming
  4. fats and oils
  5. attachment
  6. removal of dense stuff - like salt ions
  7. spine and colony formation - to increase surface area

sudden increasing in density slows sinking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are reasons for slower growth rate in diatoms

A

light limitation

nutrient limitation
(N, P, Fe) - Si not limiting here

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how does slower growing relate to shell formation

A

slower growth rate is associated with thicker shells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

experiment showing shell thickness and size in diatoms (and correlation to predators)

A

thicker shells of diatoms = less eaten by copepod nauplii

increased size of diatoms = less eaten by dinoflagellates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  1. how do spines and colonies work
A

diatoms have spines to increase drag bc of increased surface area

mechanism to allow for slower sinking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  1. flagellates
A

flagella allow for them to move purposefully

many have photoactive cells to detect light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  1. removal of dense stuff like salt ions
A

concentration of ions in diatom storage vacuoles (cell sap)

salt ions lower conc inside vacuole (inside cell) than outside

density of vacuole lower than sea water –> phytoplankton actively transport salt ions out of cell to lower density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how does nutrient availability change sinking speed ?

A

more nutrient limited - sink faster

more nutrients = sink slower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

In what ways does zooplankton size impact grazing?

A

SMALL ZOOP:
- some small zooplankton are same size as phytoplankton –> small zooplankton can only eat so big, many cant feed on large diatoms

  • can have tight coupling between zoop and phyto if both are small - they both stay at the top

LARGER ZOOP:
- larger zooplankton can graze larger organisms

  • group dependent
  • larger zooplankton are more complex and can be more selective - migration –> how they control phyto bloom dependent on timing
  • specialization
  • greater mobility
  • reproduce slower
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the difference between ML light availability and euphotic zone

A

MLD is determined by how much light is experienced by phytoplankton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is surface irradiance determined by

A

sea sun, latitude, weather, particulates (absorb and scatter light)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does mixed layer light availability depend on?

A
  1. surface irradiance –> sea sun, latitude, weather
  2. mixed layer depth
  3. particulates - absorb and scatter light
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

ingestion rate vs prey concentration

A

total ingestion also increases as predator concentration increases

ingestion increases as the prey concentration increases (up to some maximum - saturation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

trophic transfer efficiency

A

production rate at trophic level below

OR

biomass at trophic level below

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Suppose a primary production rate of 100 mmol C m-2 d-1 and a trophic transfer efficiency of 15%.
What production can you expect at the third trophic level (secondary consumer)?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how does phytoplankton size control top level biomass?

A
  1. loss at each trophic level (trophic transfer efficiency)
  2. lower biomass at phyto level
    - small phyto = characteristic of nutrient limitation
    - larger phyto = dominate at more nutrient rich systems

smaller phyto = more trophic levels = less biomass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how is trophic production linked to primary production?

A

Higher trophic production linked to primary production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

copepods

A

v abundant ~80% net samples

key link of phytoplankton to higher trophic levels

eats large phytoplankton (herbivorous) and small zooplankton (carnivorous)

sexual reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

generic copepod life cycle

A

generation time:

  • several weeks to several years depending on species and environmental conditions

nauplii:
- v diff shape than adults
- less ability to sense environment than adults –> less successful predators
- smaller
- weaker swimmers
- less sensory ability

nauplii hatch in early spring to summer bc high phyto population and therefore easier to feed - more encounters and promotes high growth

adults then go down to depth bc theyre better at feeding can survive low food availability and allows for less predation
- enter diapause where slow respiration in cold deep waters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why is this an advantageous timing for the copepod life cycle?

A

the timing of blooms makes it important for them to be hatched right at spring bloom
- since they are worse at finding food, this allows for greater success

you look cute w your glasses on.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

importance of diversity in migration timing of copepods

A

advantageous for them to come up at different times bc then theres some diversity in case blooms are different timing
- not all population follows same exact schedule

  • spring bloom timing variable (mixed layer shoaling depends on weather
  • diversity in migration and egg production timing to ensure some nauplii are born at optimal period
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What advantage does a planktonic stage give a benthic organism?

A

planktonic larvae promotes DISPERSAL with currents to other regions

an example: barnacle nauplii

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

euphausiids - krill (crunchy)

A

large

shrimplike

eats large phytoplankton and small zooplankton

multi-year life cycles (up to 5 years)

DVM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the advantage to organisms that live at depth during daytime and rise to the surface at night?

A

Diel Vertical Migration — DVM

  1. predator avoidance - lots of predators are visual, so less chance of being eaten when not seen
  2. feed where plankton biomass high at night
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

how does DVM vary by season?

A

different day lengths so there would be different pressures – maybe not as much pressure to go up and down

this would change what organisms we see in deep net tows vs shallows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Amphipods (crunchy)

A

laterally compressed / flatter than euphausiids

eats detritus almost exclusively

direct development (no nauplius)

often live commensally within large jellyfish

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Ostracods – seed shrimp (crunchy)

A

Primary sense – touch (water movement)

Eats large phytoplankton and small zooplankton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Cladocerans – water fleas (crunchy)

A

Antennae used for swimming

Largely eats detritus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Pteropods – a Mollusc (Crunchy)

A

Spend full life as plankton

look like small snails

foot has evolved into paired wings for swimming.

Most common in our samples Limacina spp.
thin, sinistrally coiled (to the left) calcareous shell

feeds by secreting a sticky mucus web

aragonite shell
- maybe most effected by ocean acidification?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Larval gastropods (Crunchy)

A

Plankton larvae

Benthic adults

Also look like small snails
thin, dextrally coiled (to the right) calcareous shell

Typically much smaller than local pteropods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Chaetognaths (Soft)

A

Carnivorous raptorial feeders

Attack plankton several times their own size

hang motionless until prey detected

use spines and hooks to grab prey

diel vertical migrators

Hermaphroditic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Larvaceans a primitive chordate (Soft)

A

Looks like a small tadpole

Secretes a mucous “house” through which water is pumped.

Food particles sieved out

When filter clogs, house abandoned and new one secreted

Old “houses” are important food source for other zooplankton and bacteria

36
Q

Jellies - gelatinous zooplankton (Soft)

A

diverse collection of species from several different phyla:
Cnidarians (i.e. true jellyfish) and Ctenophores (i.e. comb jellies) both “fish” for smaller zooplankton with tentacles

Salps (primitive chordates) are filter feeders that form dense patches

37
Q

Ctenophores - sea gooseberries

A

ctenophore tentacles are equipped with sticky cells called colloblasts

Typically up to 1 cm

Most feed on zooplankton, but some specialized to feed on other ctenophores

38
Q

Although sometimes referred to as “the insects of the sea”, why are only 13,000 copepod spp compared to at least 1M terrestrial insect species?

A

not as much diversity in the environment as terrestrial

marie population more connected than terrestrial

39
Q

reynolds number

A

at Re<100 viscous forces dominate (phytoplankton) - corn syrup

at Re>200 inertial forces dominate (like us) - air

40
Q

how to swim at low reynolds number ?

A

have to use non-reciprocal propulsive force - like a flexible oar or corkscrew

cant do like boat w oar cause would keep going back & forth

41
Q

how to catch prey at low reynolds number ?

A

copepods use complicated series of non-reciprocating movements - feeding appendages “fling and clap” strategy

no 2 pairs do the same thing

42
Q

movement (escape response) vs feeding

A

two geared system of swimming appendages

non-reciprocating movement of feeding appendages - for slow cruise swimming and food capture

escape responses generate an order of magnitude more than any animal on earth

43
Q

What is patchiness in copepods and what drives it?

A

Plankton are not perfectly spread out
- can be:
* patchy (clumped) distribution
* uniform or even distribution
* random distribution

Patchiness is caused by physical and biological processes

PHYTO - non motile so caused by physical mixing, turbulence, OR biological such as blooms or temps

ZOOP - driven by behaviour and biology - physical can contribute but since they’re motile mostly BEHAVIOURAL dominate zoop patchiness - can be driven by phyto conc in certain areas bc wanna be where phyto are to feed

zoop more patchy - also do DVM so this effects it too

44
Q

Do all species of zoop do same DVM?

A

No, varies between diff types of zoop

Lots of diff behavioural patterns

45
Q

What are 2 phenomenon that causes concentrations of plankton in ocean

A

WINDROWS

  • Plankton concentrate in convergence zones between rows
  • Divergence zone will be clear - convergent zones will hv high conc of plankton

FRONTAL ZONES

  • when 2 water masses come together
46
Q

Different scales of patchiness

A

Microscale, mesoscale, macroscale

47
Q

Problems w net sampling

A

Nets don’t catch everything - larger zoop avoid nets, one mesh doesn’t work for all

Patchiness

Nets get clogged

48
Q

Velocity of water in front of net

A

Bow wave

Caused by small mesh size - doesn’t let water thru fast enough

49
Q

What role do heterotrophic bacteria and viruses play in the ocean ?

A

Play important role in carbon cycle

  • utilizing, respiring, and remineralizing organic matter exported from surface to deep ocean

90-95% of marine bacteria are heterotrophic ↳ 70% of all living carbon in the ocean
- 20% of all bacterial biomass turns over everyday

50
Q

What dominates the flux of energy and biologically important chemical elements of the ocean?

A

Microbes - bacteria (heterotrophs), viruses (phases, animal viruses), and protists

  • total mass of bacteria in ocean exceeds combined mass of fish and zoop
  • high metabolic rates
  • turnover of carbon - 20% of bacterial mass turns over every day
51
Q

Highest to lowest bacterial cell density environments and why
- estuaries, deep sea, open ocean, coastal (near shore)

A
  1. Estuaries
  2. Coastal (near shore)
  3. Open ocean
  4. Deep sea

Estuaries have stuff from land - high oxygen and particles for bacteria to break down

Coastal ecosystems have terrestrial influence as well

Deep sea is vast so less density compared to other areas

52
Q

What happens to the bacteria in the ocean?

A
  • Consumed by other plankton → heterotrophic or microzooplankton
  • lysed by viruses
53
Q

How is bacteria and their graces similar to phyto and zoop?

A

Fight coupling between bacterial and their grazers

54
Q

What do heterotrophic marine bacteria eat?

A

DOM → organic matter that passes through a 0.45um filter
- DOC → dissolved organic carbon (main component of DOM)

55
Q

What is DOM and where does it come from ?

A

Defined at organic molecules that pass thru at 0.45um filter - mostly dissolved organic carbon

Come from:
- phytoplankton exudates
- excretory products from marine organisms
- viral lysis of of host cells
- sloppy feeding by zoop and protozoans
- sinking zoop faecal pellates
- larvacean houses

56
Q

Steeles Dilemma

A
57
Q

What are the ecological roles of heterotrophic bacteria in the marine environment?

A
  1. Recycling of nutrients
    - breakdown of DOC and turn back into inorganic nutrients to the water column
  2. Increases overall food chain efficiency
    - microzoop consumes by mesozoop
    - helps resolve steeles dilemma by providing a way to channel “bacterial carbon” back into classic food chain
58
Q

Where are marine viruses most abundant & why?

A

In upper 200m of water column

Cause this is where their host cells are - heterotrophic bacteria

59
Q

Ecological roles of viruses in marine environment?

A
  1. Recycling of nutrients (indirectly)
    - remineralization/respiration of lysed cell contents by bacteria
  2. Regulation of primary productivity
    - viral outbreaks may regulate phytoplankton blooms
  3. Other roles:
    - source of mortality
60
Q

Recycling takes place on different time scales

A
  1. In the euphoric zone and water column (relatively rapid, seasonal)
  2. In accumulated sediments (slower, up to geological time frame)
61
Q

Where does this reaction (remineralization/aerobic respiration) take place in the ocean ? Why ?

A

As long as there is oxygen, this can happen

Out of euphotic zone nitrification happens (deeper

62
Q

What is the point of nutrient recycling in marine environments ?

A
  • increases the productivity of food webs
  • enhances and extends phytoplankton productivity
  • influences composition of phytoplankton assemblages
  • is a key component of the microbial loop
  • works with other biotic and abiotic processes to form biogeochemical cycles
63
Q

What are the sources of N to phytoplankton?

A

NH3, NH4+, NO3-, NO2-, urea, amino acids, other DON and N2

N2 most abundant, but only some cyanobacteria can use it directly

64
Q

How is nitrogen assimilated?

A

Assimilation of N into amino acids requires complete reduction of the N compounds

Although phytoplankton can take N as NO3- , NO2-, urea, etc, they must first reduce these compounds to NH4+

65
Q

If provided with a mix of N compounds, which would be preferentially utilized by phytoplankton? Why?

A

NH4+ would be chosen bc the reduction usually requires ATP

66
Q

Nitrogen Cycle

A

• Remineralization occurs throughout the water column, but with different outcomes:

  • • Regenerated production:
    Portion of primary production that results from the utilization of
    “regenerated nitrogen” (mainly NH4+,
    urea
  • • New prpduction:
    Portion of primary production that results from the utilization of “new nitrogen” (mainly NO3-)
  • • Role of DON:
    Contributes to regenerated production AND to new production
67
Q

Phosphorus Cycle

A

• Phosphorus in organic material is readily respired back to inorganic P.

• P rapidly cycles through the system, so, it is seldom limiting in the marine environment.

68
Q

Silicon Cycle

A

• Only involves inorganic forms!

• Dissolution of biogenic Si is solubility driven. The ocean is undersaturated with Si, and therefore corrosive to biogenic Si.

• Skeletal material dissolves at all depths following death of the organisms and decay of organic material

• ~1/3 of material may reach sediments, only ~5% preserved

69
Q

why is iron important to phytoplankton ?

A
  1. photosynthesis
  2. nitrogen assimilation
  • used in synthesis of nitrate reductase (one of enzymes used to convert NO3 to NO2 to NH4+)
  • nitrogenase enzyme is used for N2 gas fixation by cyanobacteria
  1. synthesis of chlorophyll a
70
Q

where does iron come from ?

A

sources of iron in the ocean:

  • dust from atmosphere
  • hydrothermal vents
  • margin sediments
71
Q

what is HNLC and where

A

High Nutrient (nitrate) Low Chlorophyll regions

  • Subarctic NE Pacific
  • Eastern Equatorial Pacific
  • Southern Ocean
72
Q

old Iron Hypothesis

A

“Antarctic Paradox”

the growth of diatoms is determined by factors other than the conc of phosphates and nitrates besides light and temperature

73
Q

modern Iron Hypothesis

A
  1. Fe not very soluble in oxygenated seawater - and much of the ocean is far from terrestrial sources
  2. open ocean iron conc is very low and limiting compared to macronutrients
  3. bottle experiments showed Iron stimulated growth of large diatoms and led nutrient drawdown
  4. indirect evidence from “island effects”
74
Q

early shipboard bottle incubation experiments

A

seawater spiked with Fe and incubated on deck

with iron it doubled or tripled

another study by Martin et al found similar results of experiments in Antarctica, Alaska, and Equator
— this suggested that iron was INDEED LIMITING phyto growth in these regions

indirect evidence -
NATURAL : dust blowing from Saharan desert caused high Chl plume - biological pump

75
Q

biological pump

A
76
Q

positive feedback between dust flux and global climate

A

• Fe rich dust entering the oceans
—> Increases PP
—> Decreases CO2 in atmosphere

• Temperature decreases
—> decreases precipitation
—> increased desertification
—> more dust

77
Q

what provided evidence suggesting that Fe supply may affect atmospheric CO2 concentration ?

A

The Vostok Ice core (Antarctica)

78
Q

Despite these lines of evidence, many oceanographers still questioned the importance of Fe in the regulation of primary production:

A

1) Artifacts associated with bottle experiments hinder extrapolation to ocean temporal and spatial scales

2) Bottle experiments are not acturate representations of a true phytoplankton community

3) Possible Fe contamination or improper analytical technique could lead to faulty conclusions

79
Q

Advantages and disadvantages of large scale Fe hypothesis testing

A

advantages:
- significant increase in Chl
- drawdown of CO2
- suggest reversing anthropogenic caused climate change

disadvantages:
- possibly alter natural cycles, wiping out fish bc too productive of oceans (eutrophication)
- other problems we dont know yet

can study this naturally w volcanoes

80
Q

what does the natural Fe fertilization event show ?

A

volcano eruption brought iron and blooms

showed that bad effects could be minimal

australian wildfires fertilized bloom - may hv drawn down lots of carbon from atmosphere

81
Q

Did the Kasatochi bloom event affect Fraser River sockeye salmon?

A

suggests that bloom caused way more salmon to return

also after commercial vessel released iron sulfate, 2014 has 20 milliom sockeye return to fraser

82
Q

What limits productivity in three different locations ?
(subarctic NE Pacific, North Atlantic, subtropical N Pacific) LOOK AT THIS AGAIN

A

Subarctic NE Pacific (Ocean Station Papa) - seasonal light changes

Subtropical Pacific - light varies much less

83
Q

Which size class of phytoplankton are likely responsible for the occasional peaks in chlorophyll ?

A
84
Q

What kind of phytoplankton are good at dealing with low nutrients?

A

Small spheres are best bc they can use ammonium directly at low concs

Large phytoplankton need higher concentrations

Larger diatoms in Subarctic NE pacific can only take up higher concs of NO3- BUT require Fe

85
Q

Why is the biological pump important ?

A
  • sink for atmospheric carbon
  • important for connecting nutrient cycles
  • Pathway for organic matter to reach sea floor ecosystems
86
Q

Would atmospheric CO2

A
87
Q

How might climate change affect the biological pump ?

A

Ocean acidification - shells CaCo3 susceptible to dissolution - less efficient sinking

Temperature
- warmer water can hold less dissolved gas (CO2)
- ice coverage and timing of grazing
- stronger stratification- warmer water less dense
- less nutrient renewal

biol 321 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions