Scenario 4

Question 1

Describe the relationship between ENSO and human-induced climate change

Answer 1

regular nino/nina fluctuation is not caused by human impact
as avg sea surf temps warm, el nino will become more severe over time
aka el nino will increase in temp more and more over time- still fluctuate with temp but overall trend is upward for temp

Question 2

Describe the Enhanced Greenhouse Effect, and its primary drivers. How does it differ from the Greenhouse Effect?

Answer 2

-GE: normal thing- absorption of solar radiation- some trapped by gases in the atmosphere when reflecting off the earth
- EGE: incr in CO2 atmos. conc causes earths temp to rise bc more solar radiation is trapped

Question 3

List and explain the various ways in which human-induced climate change impacts the world’s oceans.

Answer 3

warming sea surface temps
marine communities- organisms may be forced to move based on temp changes
stress on sessile organisms that are unable to move- eg coral

Question 4

Explain the impact of warming ocean temperatures on the Great Barrier Reef

Answer 4

widespread bleaching- fewer gaps between major bleaching events- less time to recover
half the areas corals have already died
by the end of the century bleaching events will happen back to back every summer

Question 5

Explain how the ocean’s buffering system works, and describe how it relates to ocean acidification.

Answer 5

prevents major pH swings
normally, co2 dissolves into the ocean and combines with h2o to make unstable carbonic acid (h2co3) that quickly becomes bicarbonate (h+ and hco3-) (so co2 is absorbed so quickly bc in the water it’s instantly changed to something else so the conc in the air will always be higher than in the water)
then carbonate is able to collect free H+ ions and as H+ conc increases, bicarbonate will also grab these and turn back into carbonic acid
removes carbonate- harms molluscs and coral, eg, that use carbonate for their shells, etc
huge CO2 sink- absorbs 50-60% more than the atmosphere

Question 6

Explain how climate change and ocean deoxygenation are related, and describe the impact on fish species as detailed in the required reading.

Answer 6

As sea surface temperatures increase, the ocean’s ability to dissolve oxygen decreases.

Question 7

Explain what types of marine organisms are most heavily impacted by ocean acidification, and why. What ramifications might these impacts have on the greater marine ecosystem?

Answer 7

Those that utilize calcium carbonate
- eg: muscles, pteropods

Question 8

TRUE OR FALSE: Warming sea surface temperatures is increasing the amount of CO2 dissolved into the ocean, causing pH levels to drop. FIX IF FALSE

Answer 8

FALSE:
- Warming sea surface temperatures is increasing the amount of CO2 dissolved into the ocean, causing pH levels to RISE

Question 9

TRUE OR FALSE: Warming sea surface temperatures increases the density of surface water, causing the global conveyor belt system to slow. FIX IF FALSE

Answer 9

FALSE:
- Warming sea surface temperatures DECREASES the density of surface water, causing the global conveyor belt system to slow.
- at the poles, the water is FRESHER bc of MELTING ICE (as well as warmer)

Question 10

TRUE OR FALSE: Warming sea surface temperatures decreases the ability of ocean water to hold dissolved oxygen. FIX IF FALSE

Answer 10

TRUE

Question 11

What BEST describes why human-induced climate change is causing deoxygenation of the world’s oceans?

Answer 11

As sea surface temperatures increase, the ocean’s ability to dissolve oxygen decreases.

Question 12

conformance

Answer 12

internal state CHANGES to MATCH external state
- linear direct relationship (y = mx + b)
- eg: cold shock in sea turtles

Question 13

regulation

Answer 13

MAINTAINING usual conditions DESPITE envi change
- straight line across x axis despite y axis input (x = n)

Question 14

acclimation

Answer 14

response to envi change by establishing a NEW EQUILIBRIUM
- after exposure to new envi, we see:
initial response
adjustment period
new steady-state acclimation completed

Question 15

2 major types of coral reefs

Answer 15

coastal reefs
atolls

Question 16

coastal reefs

Answer 16

wide variety of reefs
- from massive (eg: great barrier reef) to small patches

Question 17

atolls

Answer 17

horseshoe or ring-shaped chain of islands on top of a seamount
- formed from ancient volcanos- grew upwards from sinking volcanos- keep “lagoons”- former pit inside volcanos- protected from wave action

Question 18

seamount

Answer 18

an underwater mountain with steep sides rising from the seafloor

Question 19

Explain how depth zonation impacts coral reef ecosystems.

Answer 19

• wave + current strength
• light intensity (esp important bc of symbiotic zooxanthellae in corals)
• suspended sediment
  competition among species leads to dominance in certain zones

Question 20

corals: phylum, class, order

Answer 20

p: cnidaria
c: anthozoa
o: scleractinia

Question 21

major coral bio characteristics

Answer 21

• some solitary (single polyp + skeleton), some colonial + connected by living tissue

Question 22

hermatypic corals

Answer 22

hard corals that form reefs
have a calcium carbonate skeleton

Question 23

2 divisions of hermatypic corals

Answer 23

massive
branching
(***there are also intermediates btwn these)
- pretty self-explanatory- form large massive shapes vs smaller intricate branching designs

Question 24

Ahermatypic corals

Answer 24

soft corals
no symbiosis w/ zooxanthellae

Question 25

coral reproduction

Answer 25

hermaphroditic and/or occur as separate sexes
2 possible types of gamete production:
- brooding
- broadcast-spawning
also reproduce asexually: budding + fragmentation

Question 26

coral brooding

Answer 26

1 type of sexual gamete production
- planktonic sperm fertilize sessile eggs
- planula larvae is planktonic

Question 27

coral broadcast spawning

Answer 27

1 type of sexual gamete production
- both types of gametes excreted into water column
- fertilization occurs in water column
- carried by water current + settles somewhere new
- often synchronized in mass-spawning events across multiple species

Question 28

which type of coral forms symbiotic relationships w zooxanthellae?

Answer 28

hermatypic (hard-bodied)

Question 29

Explain the coral-zooxanthellae symbiosis

Answer 29

• driving force of coral reef growth
• zoox. live intracellularly in vacuoles of coral cells (concentrated in the external arms/tentacles)
• to some extent zoox. can be free-living but we haven’t studied it much

Question 30

benefits to both organisms from coral-zooxanthellae symbiosis

Answer 30

• zoox get a stable environment, eliminated competition, shelter
• corals are able to feed themselves, but zoox can supplement nutrients
• mainly zoox provide carbon necessary for making hard outer skeleton!!- corals would NOT be able to w/o zooxanthellae

Question 31

Be able to explain the biological mechanisms behind how coral bleaching works.

Answer 31

• under stress, corals expel healthy zoox
• evidence that coral’s immune system is weakened after zoox expulsion (why do we know it’s from the expulsion and not the stress in general?)

Question 32

Differentiate between acclimation and adaptation as it relates to corals responding to warming water temperatures.

Answer 32

Adaptation is a long-term permanent adjustment of a group of organisms to a changing environment.
- occurs slowly over many generations
Acclimatization is a short-term rapid temporary adjustment of an organism to a changing environment.
- can be reversed once the previous conditions are met

Question 33

coral adaptation vs acclimatization related to marine heatwaves

Answer 33

• increased freq + intensity of MHWs mean that the corals don’t have enough time to recover and adapt over generations- will likely just die off at higher rates instead