CORAL SKELETONS - STORAGE AND RECOVERY OF ENVIRONMENTAL INFORMATION

Understanding the nature and causes of past global change is a key to understanding what may happen in the future. The discovery, nearly 25 years ago, of annual density bands in skeletons of long-lived, massive corals promised high-resolution proxy climate records for tropical oc eans. The tropics are regions of major importance to the global climat e system and they are poorly represented by high-resolution proxy clim ate records such as tree rings, ice cores and historical documents. In this review we examine the principles and procedures underlying routi ne recovery and interpretation of information from proxy environmental recorders. We summarize an extensive literature which indicates that coral skeletons are excellent archives for considerable and diverse en vironmental information. We show that this potential has not been full y realized, largely because corals seemed to yield inconsistent, somet imes conflicting, information. We discuss ways in which much of this c onfusion is resolved by new understanding of coral skeletal growth mec hanisms. We also examine several records which indicate that corals ca n meet requirements for reconstruction of useful, reliable environment al information.