Biosphere 2 coral reef

There are no published studies of silica on coral reefs. Silica minerals are not abundant on coral reefs, so the biogeochemistry of silica has been ignored. It is evident, however, from the results of our uptake experiments (we measure silica in all our experiments) that silica concentrations in the water sometimes decreases and sometimes increases. This result is probably related to whether benthic diatoms are occupying the reef surfaces. At Biosphere 2 coral reef mesocosm, silica goes through a distinct seasonal cycle related to blooms of benthic diatoms (Atkinson etal., 2001). Concentrations of silica in pore-water can also change seasonally (Falter, 1998). 

Atkinson, M.J., Falter, J.L. and Hearn, C.J. (2001) Nutrient dynamics in the Biosphere 2 coral reef mesocosm water velocity controls NH4 and P04 uptake. Coral Reefs, 20, 341-346. 

Falter, J.L., Atkinson, M.J. and Langdon, C. (2001) Production-respiration relationships at different time-scales within the Biosphere 2 coral reef biome. Limnology and Oceanography, 46, 1653-1660. 

Changes in the biosphere are also important indicators of climate. One is the bleaching of corals. It is important to recognize that enhanced atmospheric forcings on coral reefs lead not to their disappearance but to their transformation into more resistant species (Hughes et al., 2003). Changes in seawater properties are another indicator (Broecker, 2003). 

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