threats to coral reefs

Question 1

Pollution

Answer 1

• CO2 from atmosphere absorbed into ocean, leads to acidification
• breaks down calcium carb and compromises structural integrity of coral reefs
• sediment/land-based pollutants can wash into ocean, making water murky = less light = less photosynthesis = less growth
• toxic/dangerous, e/g plastics/insecticides. damages corals and ecosystem they depend on

Question 2

SL rise

Answer 2

• global temps rise, glaciers melt so SL rises
• if Sl rise faster than coral growth, corals may be too deep to get enough light
• rise in SL can cause more coastal erosion, so more sediment transported which can lead to sedimentation in coral reefs, blocking sunlight etc
• worse in fringing where closer to shoreline

Question 3

global warming

Answer 3

• coral bleaching, when algae leaves corals so more susceptible to disease
• occurs when temp too high to survive in corals, so die and leave white skeleton type thing
• more diseases thrive in warm waters, harming corals and reefs
• more frequent/strong storms can disrupt/destroy reefs
• changing ocean currents disrupt food chains + wave action

Question 4

physical damage

Answer 4

• boating can damage reefs, esp if anchor dropped onto reef
• large boats bulldoze through and destroy
• destructive fishing can damage (bottom trawling is where large net dragged on sea floor, v disruptive to reefs)
• unsustainable tourism e.g snorkelling can damage esp if ppl touch