Climate Change Ocean & Marine Systems 2

Question 1

Which coastal ecosystems are recognized as the most effective stores of 'blue carbon'?

Accepted Answer

Mangroves, seagrasses, and salt marshes

Answer

Rocky intertidal zones and coral reefs

Answer

Open-ocean phytoplankton blooms and kelp forests

Answer

Sandy beaches and tidal estuaries

Question 2

What are the two primary physical mechanisms driving global sea level rise in a warming climate?

Accepted Answer

Thermal expansion of seawater and melting of land-based ice sheets and glaciers

Answer

Groundwater depletion and increased river sediment discharge

Answer

Increased ocean precipitation and reduced evaporation rates

Answer

Shifting ocean currents and tectonic plate subsidence

Question 3

Marine heatwaves are formally defined as periods when sea surface temperatures exceed what threshold?

Accepted Answer

The 90th percentile of local climatological temperatures for at least 5 consecutive days

Answer

The monthly seasonal average for that location

Answer

An absolute threshold of 30°C (86°F) for more than 14 days

Answer

2°C above the long-term monthly mean for any duration

Question 4

Which major Atlantic circulation system is considered most vulnerable to weakening as Arctic ice melts add freshwater to the North Atlantic?

Accepted Answer

Atlantic Meridional Overturning Circulation (AMOC)

Answer

El Niño–Southern Oscillation (ENSO)

Answer

Antarctic Circumpolar Current (ACC)

Answer

Pacific Decadal Oscillation (PDO)

Question 5

What is ocean deoxygenation and why does climate change accelerate it?

Accepted Answer

The widespread loss of dissolved oxygen driven by warming reducing gas solubility and increased stratification limiting replenishment

Answer

The process by which marine plants release oxygen during photosynthesis in warmer conditions

Answer

The seasonal depletion of surface oxygen during colder winter months globally

Answer

A deep-ocean chemical reaction that consumes oxygen near hydrothermal vents

Question 6

How does climate change most directly affect the geographic distribution of marine species?

Accepted Answer

Many species shift poleward or to deeper, cooler waters to track their preferred temperature range

Answer

Species remain in traditional ranges due to strong evolutionary habitat fidelity

Answer

Tropical species aggressively outcompete and replace temperate species at mid-latitudes

Answer

Marine species distributions are largely unaffected because oceans buffer temperature changes well

Question 7

Mass coral bleaching events on the Great Barrier Reef are primarily triggered by which climate-related factor?

Accepted Answer

Elevated sea surface temperatures during warming events amplified by global climate change

Answer

Increased UV radiation from stratospheric ozone depletion over Australia

Answer

Ocean acidification dissolving the calcium carbonate reef framework directly

Answer

Increased sediment runoff following more intense rainfall events