Describe coral reef systems of island fringing reefs and island atolls.

Describe coral reef systems of island fringing reefs and island atolls. Include in your answer: a. origin of coral reef islands and atolls and the biological growth of corals, b. the nature of primary producers of coral reef systems and the value of Gregory-protected algal mats, c. the conditions under which separate sexes versus protogynous and protandrous sex-reversal are advantageous, d. specialized adaptations of three different families of fishes that typify reef ecosystems.