Coral reefs are the largest landforms built by plants and animals. Their study therefore incorporates a wide range of disciplines. This encyclopedia approaches coral reefs from an earth science perspective, concentrating especially on modern reefs. Currently coral reefs are under high stress, most prominently from climate change with changes to water temperature, sea level and ocean acidification particularly damaging. Modern reefs have evolved through the massive environmental changes of the Quaternary with long periods of exposure during glacially lowered sea level periods and short periods of interglacial growth. The entries in this encyclopedia condense the large amount of work carried out since Charles Darwin first attempted to understand reef evolution. Leading authorities from many countries have contributed to the entries covering areas of geology, geography and ecology, providing comprehensive access to the most up-to-date research on the structure, form and processes operating on Quaternary coral reefs.

A study of coral reefs is of great theoretical and practical importance in biology, geology, ecology, and for understanding the history of ocean basins and seacoasts. As a biological formation, the reef represents one of the rare natural marine ecosystem models with the highest biological productivity. Contemporary reef systems exert an extremely important influence on the overall biological control of the World Ocean. Coral reefs have been recognized as one of the richest natural ecosystems and could be considered a prototype of a highly productive marine economy.

Deep-water coral reefs are found along large sections of the outer continental shelves and slopes of Europe, from North Cape to the Gulf of Cadiz, and because they also occur along the Atlantic seaboard of USA, the Gulf of Mexico, off Brazil, in the Mediterranean, and off New Zealand, they are currently being targeted by international groups of marine scientists. They have become popular and opportune deep-water research targets because they offer exciting frontier exploration, combined with a whole plethora of modern scientific methods, such as deep-sea drilling, sampling, remote control surveying and documentation. Furthermore they represent timely opportunities for further developments within the application of geochemistry, stable isotope research, bacterial sciences, including DNA-sequestering, and medical research (search for bioactive compounds). The Integrated Ocean Drilling Program (IODP) has arranged a deep-sea scientific drilling campaign on giant carbonate banks off Ireland. Because the reefs currently defy traditional marine-ecological theories, they represent future research opportunities and will enjoy scientific scrutiny for many years to come.

Published by the American Geophysical Union as part of the Coastal and Estuarine Studies, Volume 61. The effects of increased atmospheric carbon dioxide and related climate change on shallow coral reefs are gaining considerable attention for scientific and economic reasons worldwide. Although increased scientific research has improved our understanding of the response of coral reefs to climate change, we still lack key information that can help guide reef management. Research and monitoring of coral reef ecosystems over the past few decades have documented two major threats related to increasing concentrations of atmospheric CO2: (1) increased sea surface temperatures and (2) increased seawater acidity (lower pH). Higher atmospheric CO2 levels have resulted in rising sea surface temperatures and proven to be an acute threat to corals and other reef-dwelling organisms. Short periods (days) of elevated sea surface temperatures by as little as 1–2°C above the normal maximum temperature has led to more frequent and more widespread episodes of coral bleaching-the expulsion of symbiotic algae. A more chronic consequence of increasing atmospheric CO2 is the lowering of pH of surface waters, which affects the rate at which corals and other reef organisms secrete and build their calcium carbonate skeletons. Average pH of the surface ocean has already decreased by an estimated 0.1 unit since preindustrial times, and will continue to decline in concert with rising atmospheric CO2. These climate-related Stressors combined with other direct anthropogenic assaults, such as overfishing and pollution, weaken reef organisms and increase their susceptibility to disease.

The health status and future of tropical coral reefs, as tourist destinations, are regularly subjected to media coverage. Many documentaries recognize the natural beauty and biological richness of the Australian Great Barrier Reef and French Polynesian lagoons, but point to the equally significant risk that would result from current global warming and human-made hazards. The future of coral reefs is usually a matter of death foretold, real or purely imaginary. In this context, it has become necessary to differentiate between what is falling within reality of scientific facts or fantasy. To this end, the present general review, in the expert translation of Charlotte Fontan aims at: (1) defining the conditions and life requirements of reefbuilding corals; (2) the history of corals along with that of a number of associated, skeletal organisms involved in reef building since the very beginning, i.e. the last 540 million years, including the ups and downs they have experienced; (3) giving special reference to the development patterns of recent and modern reefs; (4) projecting corals and reefs into a still unknown future. Understanding how corals and reefs have originated, how they have been able to face the major biological crises which have punctuated the Earth’s history, how they have survived is a prerequisite to better gain a significant picture of their future.

Illustrated throughout, this book presents what is known about factors that "shift the balance" between accretion and erosion, recruitment and mortality, stony corals and filamentous algae, recovery and degradation - the life and death of coral reefs.