Growth Rates in Montastraea Annularis: A Record of Environmental Change in Key Largo Coral Reef Marine Sanctuary, Florida
Abstract:Annual growth rates of Montastraea annularis over the last 50+ years were determined for inshore, midshore, and offshore reef areas within the Key Largo Coral Reef Marine Sanctuary, Florida. In this study, 144 massive heads of M. annularis were sampled by coring and their growth history examined, using X-radiography to facilitate accurate measurement of more than 7,000 individual annual growth increments.
Key elements affecting growth and survival of M. annularis in the sanctuary appear to be water depth, turbidity, and temperature. Montastraea annularis from offshore fore-reef areas grew most slowly, averaging only 6.3 mm of vertical growth per year from 1928 to 1978. Many cores at this location reveal a long history of environmental stress indicated by numerous healed-over “die-off” voids excavated by various boring organisms, principally boring sponges. Abnormal density layers (stress bands) are common. Montastraea annularis from three reef areas nearest shore revealed a similar record of environmental stress, but grew slightly faster at an average rate of 8.2 mm per year. Stress banding and bioerosion voids are common in all cores from this area as well. Growth rates of M. annularis were highest in midshore reef areas, averaging 11.2 mm per year at three of five sites. Stress banding was minimal in most cases, as were incidences of massive skeletal damage by bioerosion.
Environmental implications, though circumstantial, are provocative in that the recent decline in coral growth (1953 to 1968) at some midshore and inshore reefs coincides with increased dredge and fill operations in the Florida Keys area. A slight overall resurgence in coral growth on these same reefs (1973 to present) coincides with a ban on these operations.
Document Type: Research Article
Publication date: April 1, 1981
More about this publication?
- The Bulletin of Marine Science is dedicated to the dissemination of high quality research from the world's oceans. All aspects of marine science are treated by the Bulletin of Marine Science, including papers in marine biology, biological oceanography, fisheries, marine affairs, applied marine physics, marine geology and geophysics, marine and atmospheric chemistry, and meteorology and physical oceanography.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Terms & Conditions
- Ingenta Connect is not responsible for the content or availability of external websites