CORAL REEFS
GENERAL:
- Comprised of millions of coral polyps (small marine animals which thrive in colonies)
- When they die their calcium carbonate (limestone) skeletons form a limestone structure
upon which new generations of coral grow
- Reefs usually run parallel to the coastline
- Once established, they can grow 60cm/yr if condition are right
- The are very diverse
• There are 800 types of coral
• They provide a habitat for 25% of all known marine species but occupy only 1% of the
worlds seas
SYMBIOTIC RELATIONSHIP:
- Algae live inside the coral body
- Coral produces CO2 and water in respiration which algae uses to photosynthesise
- The algae produces sugar and O2 in photosynthesis which the coral uses to respire
- If sea temp. rises too high, the alga leave, causing the corals to appear white (bleach) and
then die if algae do not return
- Algae are very sensitive and any changes in their optimum conditions can cause them to
abandon the coral polyp
DISTRIBUTION OF CORAL REEFS:
- Mainly along the line of the equator
- Majority near Australia and Indonesia
- Lots near Central America and East Coast of Africa
- Fringing reefs and barrier reefs found along coastlines, all types found in deep water
CONDITIONS REQUIRED FOR CORAL GROWTH:
- Temperature:
• Minimum of 18 degrees C but grow best between 22-25 degrees C
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