Geographic Distribution of Coral Reefs

Coral reefs exist in tropical areas worldwide (Figure 8). In general, reefs are abundant in areas with shallow coastlines and clear, warm water where riverine discharge of sediments is low. Large coral reefs are rarely found in areas above 29° latitude where ocean temperatures fall below 18 °C for extended periods as this slows coral growth and their capacity to build large reefs; however, zooxanthellate corals can be found in areas with water temperatures as low as 11 °C. In addition, herbivory is often less intense in cooler waters meaning that seaweeds are more abundant in temperate areas and that competition between corals and seaweeds is more intense. The combination of cooler water temperatures and more intense competition with abundant seaweeds likely interact to limit the latitudinal range of large coral reefs. However, when the physical and

Figure 8 Worldwide distribution of coral reefs. Coral reefs (red dots) cover roughly 250 000 km2 of the Earth's surface, but zooxanthellate corals inhabit a far wider range (blue shading). From Veron JEN (2000) Corals of the World, vols. 1-3. Townsville, QLD: Australian Institute of Marine Science.

ecological criteria are met, the results can be phenomenal. For example, the most biologically diverse reefs occur in the tropical Indo-Pacific in the areas around Indonesia and the Philippines and house over 550 species of coral and thousands of species of fish. The Great Barrier Reef off northeastern Australia is the largest reef in the world with more than 2800 individual reefs occupying over 1800 km of the Australian coastline and can be seen from outer space.

Was this article helpful?

0 0
Project Earth Conservation

Project Earth Conservation

Get All The Support And Guidance You Need To Be A Success At Helping Save The Earth. This Book Is One Of The Most Valuable Resources In The World When It Comes To How To Recycle to Create a Better Future for Our Children.

Get My Free Ebook

Post a comment