Tropical coral reefs
Cards (6)
- How humans benefit from tropical coral reefs:
- provides income from tourism/recreation
- can be used for medicines
- can be researched for biomimetics
- provides protection from coastal erosion/storm damage
- it is a carbon sink
- provides food
- Ecological features:
- Warm (25-27 C) and stable water temperature
- high light levels
- low turbidity
- low tidal range/permanent submersion
- constant salinity
Corals:- cilia - projections that trap planktonic organisms
- nematocysts - stinging cells
- symbiotic algae - absorb sunlight which provides energy for themselves and the coral polyps e.g. zooxanthellae
- secretion of a limestone base to build up a reef providing habitats
- Importance:
- fisheries - fish and lobsters
- medicine - coral sponge provides AZT which treats HIV/AIDS
- climate control - carbon sink
- erosion protection - absorb wave energy due to their irregular shapes
- tourism
- Threats:
- local
- physical damage e.g. dredging
- exploitation of resources - overfishing and coral harvesting
- pollution - sedimentation blocks mouths, sewage = eutrophication
- general reef resilience is decreased and vulnerability to disease is increased
- global
- increasing sea temperature causes coral bleaching
- ocean acidification
- diseases
- Conservation efforts:
- marine protected areas
- fixed mooring buoys so no anchors used
- education on not to touch the corals
- control of fishing
- No Take Zones
- length of fishing season is reduced
- control of tourism
- activities restricted e.g. spear fishing and collection of souvenirs
- sustainable exploitation
- CITES Appendix 2
- reef creation
- artificial reefs on concrete structures
- Examples:
- Thailand has around 121 km of coral reefs mostly on the East coast
- It is made of hard corals that are vulnerable as they rely more on algae for food, so have a smaller population .
- 37% are damaged by overfishing, pollution and rising sea temperatures
- There is a 5 year coral reef management scheme