Below are selected pictures of reefs. More photographs of reefs are available in the country sections found on the left.
Except where noted, all images are the property of Rhett A. Butler, copyright 1994-2006. Contact me with questions regarding use, reproduction, or purchase of any of the pictures.
A coral reef is a type of biotic reef developing in tropical waters. Although corals are major contributors to the overall framework and bulk material comprising a coral reef, the organisms most responsible for reef growth against the constant assault by ocean waves are calcareous algae, especially, although not entirely, species of red algae.
Water temperature of 20–28 °C (68–82 °F) is needed for growth of the coral reef. Coral reefs are found in all oceans of the world, generally between the Tropic of Cancer and the Tropic of Capricorn, because reef-building corals live in these waters. Reef-building corals are found mainly in the photic zone (<50m), where the sunlight reaches the ground and offers the corals enough energy. The corals themselves do not photosynthesise, but they live in a symbiotic relationship with types of microscopic algae that photosynthesise for them. Because of this, coral reefs also grow much faster in clear water, which absorbs less light.
Pictures were taken by Rhett A. Butler, copyright 2008. While these photos are the property of mongabay.com, it may be permissible to use them for non-commercial purposes (like powerpoint presentations and school projects), provided that the images are not altered in any form. Please read this for more details. If you are interested in using an image in a publication please contact me.
