What is a characteristic of the great barier reef

The waters are generally crystal-clear, with submarine features clearly visible at depths of 100 feet (30 metres).They: protect coastlines from the damaging effects of wave action and tropical storms. provide habitats and shelter for many marine organisms. are the source of nitrogen and other essential nutrients for marine food chains.

Explanation:

The waters are generally crystal-clear, with submarine features clearly visible at depths of 100 feet (30 metres).They: protect coastlines from the damaging effects of wave action and tropical storms. provide habitats and shelter for many marine organisms. are the source of nitrogen and other essential nutrients for marine food chains.

Explanation:

the answer would be in this answer. someone already asked the question.  

answer; i believe the correct answer is (8) eight.