OA lecture 1- Jasmine

Question 1

Describe what anthropogenic activities lead to ocean acidification

Answer 1

Industrial revolution to present
Development of new energy systems
Development of chemistry industry
Changes in agriculture & land-use

Direct + Indirect effects

Question 2

Describe some issues with the basic seawater carbonate system. This doesn’t make any sense sorry

Answer 2

Rising atmospheric CO2 concentrations are affecting the ocean carbonate chemistry
Natural buffering capacity of the oceans has maintained ocean pH at around 8-8.1
Imbalance in the natural carbonate system due to rising CO2 means that pH is reducing, and the carbonate saturation state is declining

CaCoO3<-> CO32- + Ca2+

Question 3

Which chemical affects the absorption of atmospheric CO2 in the ocean.

formation and dissolution rates vary with …

Answer 3

Atmospheric CO2 can only be absorbed if enough CaCO3 dissolves in the water column or sediments
CaCoO3<-> CO32- + Ca2+ so CaCO3 formation and dissolution rates vary with SatRate

Question 4

Shell & skeletal formation (calcification) : Ω > 1 (supersaturation)
is this biotic or abiotic?

Answer 4

Biotic

Question 5

Shell & skeletal dissolution: Ω < 1 (undersaturation)
is this biotic or abiotic

Answer 5

dependent on abiotic environment

Question 6

What are the (3) abiotic controls of the carbonate saturation state

Answer 6

CO2 solubility depends on temperature, salinity and pressure
….is less soluble at warmer temperatures

• Higher CaCO3 saturation states in shallow, warm tropical waters
• Lower CaCO3 saturation states in cold, high-latitude regions and at depth

Question 7

what are the two main forms of CaCO3

Answer 7

Calcite
Aragonite

Question 8

tell me where you find aragonite

Answer 8

: many tropical corals, cold-water corals, pteropods and mollusks

Question 9

where is calcite found?

Answer 9

coccolithophores, foraminifera, echinoderms and crustaceans

Question 10

Effects of high atmospheric co2 are more…?

Answer 10

effects of high atmospheric CO2 more pronounced in colder & deeper regions of the oceans

Question 11

Which is more soluble
aragonite or calcite?

Answer 11

Aragonite more soluble than calcite, which has implications for organisms that rely on aragonite for shell and skeletal formation (A before C)