1. History of Eastern Pacific Coral Reef Research

During the Nineteenth and early Twentieth Centuries several renowned researchers—e.g., C. Darwin, J. Dana, A. Agassiz, A.E. Verrill, and T.W. Vaughan—remarked on the absence of coral reefs in the eastern tropical Pacific (ETP), concluding this was due mainly to the influence of cool currents and upwelling centers. From later surveys in southern Mexico in the 1920s (R.H. Palmer), and the Allan Hancock Expeditions across the eastern tropical Pacific in the 1930s (C. Wyatt Durham), workers began to recognize the presence of modest structural coral reef development at several sites in the ETP. A new era of coral reef studies began in the 1970s, and has increased in pace and intellectual depth to the present. This latest surge in coral science was a result of locally active researchers, especially in Mexico, Costa Rica, Panama, and Colombia, and more recently in Ecuador and Chile. Progress in coral research in El Salvador and Nicaragua was thwarted from the 1970s to the early 1990s because of political turmoil and violence in this sector of the eastern Pacific. The establishment of national research funding agencies in Latin American countries, such as CONACYT (Mexico), CONICIT (Costa Rica), COLCIENCIAS (Colombia), and FONDECYT (Chile), has greatly benefitted coral reef research as well as scholarship opportunities for resident students to pursue advanced studies in marine science. The availability of vessels to support research in remote areas and at offshore sites has also facilitated ETP coral studies. Contrary to early views, structural coral reefs were discovered in major upwelling centers—southern Mexico (Huatulco), Costa Rica (Guanacaste), and Panama (Gulf of Panama). The number of known coral species approximately doubled from the late 1940s to 2000, from 60 (total scleractinians) and <20 (reef-building or zooxanthellate corals) to >120 and >40 species, respectively. Additionally, reports of the appearance or disappearance of extralimital coral species (e.g., in the genera Montipora, Siderastrea, Acropora, and Millepora) have added to the excitement and adventure of eastern Pacific studies. On site observations during two very strong El Niño-Southern Oscillation (ENSO) disturbances, 1982–83 and 1997–98, demonstrated that acute temperature stress can cause widespread coral bleaching and mortality and interference with reef growth. More recently, ETP waters have been found to have low pH and aragonite saturation state, which can also weaken carbonate structures and interfere with reef development. Recognizing the economic, scientific, and esthetic value of ETP coral reefs, several national and international agencies are now supporting coral research, which will have a salutary effect in increasing our knowledge and understanding of these long-neglected ecosystems.