Explain one factor that controls the distribution of coral reef ecosystems.

Temperature of the water (1) (tropical) coral needs optimum temperature of 25°c (1). • Temperature of the water (1) coral needs a minimum of 18°c degrees for growth (1). • Water depth (1) as coral needs less than 25m to survive (1). • Water depth (1) affects light penetration from sunlight (1). • Salinity (1) as corals are marine life and can only survive in saltwater (1).