PADI Marine Biology & Conservation 4

Question 1

Which chemical process is causing ocean pH to decrease over time, threatening shell-forming marine organisms?

Accepted Answer

Ocean acidification from CO₂ absorption

Answer

Oceans absorb about 30% of atmospheric CO₂, which reacts with seawater to form carbonic acid, lowering pH and reducing carbonate ions needed for shells and skeletons.

Question 2

What role do mangrove forests play in marine ecosystems?

Accepted Answer

They serve as nursery habitats, storm buffers, and carbon sinks

Answer

Mangroves provide critical nursery habitat for juvenile fish and invertebrates, protect coastlines from storm surge erosion, and sequester large amounts of carbon.

Question 3

What is bioluminescence in marine organisms, and which group is well known for this ability?

Accepted Answer

Light production through chemical reactions; dinoflagellates and deep-sea fish

Answer

Bioluminescence is the biological production of light via chemical reactions (luciferin-luciferase); dinoflagellates, anglerfish, and many deep-sea creatures use it for attraction, defense, or communication.

Question 4

Which diving practice causes the most physical damage to coral reefs during recreational diving?

Accepted Answer

Poor buoyancy control leading to contact with corals

Answer

Divers with poor buoyancy control accidentally contact and break coral polyps, which take decades to grow; even brief touches can introduce bacteria and disease.

Question 5

What is the significance of 'upwelling' in marine ecosystems?

Accepted Answer

It brings cold, nutrient-rich water to the surface, supporting high productivity

Answer

Upwelling brings deep, cold, nutrient-rich water to sunlit surface layers, fueling phytoplankton blooms and supporting highly productive fisheries and marine food webs.

(PADI) Certified Professional Association of Diving Instructors Diver Practice Test

(PADI) Certified Professional Association of Diving Instructors Diver Practice Test

PADI Marine Biology & Conservation 4