L23 Flashcards
1
Q
What is the most extreme forecast illustrated of ocean pH?
A
7.8
2
Q
Ocean chemistry and CO2
A
- Some CO2 in sea water remains as dissolved gas, which can exchange with the atmosphere and be taken up by marine photoautotrophs
- The remaining dissolved CO2 combines with molecules of water to form carbonic acid
3
Q
Carbonic acid
A
- Dissociates into hydrogen and bicarbonate
- Reduces the pool of carbonate ions available in seawater
4
Q
Consequences of increased atmospheric CO2 on seawater
A
- Decreased concentrations of carbonate ions
- Decreased pH
5
Q
Why is carbonate important to marine organisms?
A
Building shells etc
6
Q
Current oceans
A
- A higher pH than previous millenia
7
Q
Calcifying Bivalves
A
Have high commercial value and are ecosystem engineers
Calcification is worse at high CO2
8
Q
High CO2 effects on sharks
A
- Acidifies the blood and tissues of water-breathing marine animals
9
Q
Acidification and Olfactory sense
A
- Tested in smooth dogfish
- Treatments of varying CO2
- Odor tracking is reduced under future ocean acidification conditions
10
Q
Why is this controversial?
A
It does not effect the impact of coral reef fish (Clark et al)
11
Q
Limitations of these experiments
A
- Typically single species
- Often don’t have enough time for acclimation, or multiple generation effects
-Often the high pCO2 treatments are quite extreme
12
Q
Experiments in nature
A
- 30% reduction in species numbers
13
Q
Recovery from ocean acidification
A
- Pumping sodium hydroxide over a reef increasing seawater alkilinity
- 17% of alkalinity taken up by community
- shows that effects of ocean acidification can be reversed
- only a small study at a single site, not feasible at larger scales
