Environmental Quality and Preservation: Bedrock Beneath Reefs, The Importance of Geology in Understanding Biological Decline in a Modern Ecosystem

United States Geological Survey. 2000. Environmental Quality and Preservation: Bedrock Beneath Reefs, The Importance of Geology in Understanding Biological Decline in a Modern Ecosystem. U.S. Geological Survey (USGS) Open-File Report. USGS Open-File Report 00-046

The corals that form the middle and upper Florida Keys verify the previous existence of an inshore reef ecosystem. Mangrove peats found beneath offshore reefs record the locations of earlier, seaward, shorelines. Zonation of coral species within a reef is evidence of increasing water depth and thus changing conditions, from quiet water protected from waves to high-energy surf to water too deep for a surf zone. Sea level has risen and fallen many times before, and the massive limestone outlier reefs were accordingly colonized, killed during exposure, and re-colonized. These signatures in the geologic record indicate that reefs and shorelines have come and gone in the past. Could the fragile modem ecosystem be undergoing yet another natural decline, or are human activities responsible or, at the very least, an added component? We cannot know without first knowing what controlled evolution and development of the ancient reefs, i.e., the bedrock characteristics, the processes that produced them, and the responses the ancient reefs had to environmental change. The bedrock is far more important than simply being the surface beneath modem reefs. The environmental signatures it contains provide the baseline information from which understanding decline of the modem reef ecosystem must be derived

Type
Published Report
Authors
United States Geological Survey
Date of Issue
2000-04
Units
SFCN
Keywords
Formation, geologic features, Geology, History, Hydrology

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