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10.2.2 Calcification and Primary Production in Coral Reefs
One conspicuous characteristic of coral reefs is the huge production of CaCO 3 by
which tiny corals build the world’s largest living structures, such as the Great Barrier
Reef in Australia, which is visible from space. Coral reef environments can be
roughly divided into three parts: reef flat with reef crest, inner reef, and outer reef
(upper panel in Fig. 10.3). The reef flat with reef crest is the shallowest part of a
coral reef and is covered with either corals or macroalgae. Incoming wave energy is
Fig. 10.2 Buffering capacity of seawater as a function of pCO 2 at varying water temperatures
(salinity = 35 and the total alkalinity = 2300 μmol kg
−1 )
SEAGRASS BED
OUTER REEF
INNER REEF
LAGOON
(or MOAT if shallow)
MANGROVES
BEACH
REEF CREST
REEF FLAT
CORALS
BED ROCK
CHANNELS
CHANNELS
LAGOON
CHANNELS
REEF CREST
Fringing reef
Barrier reef
Atoll
MOAT
REEF
CREST
CHANNELS
Fig. 10.3 General reef geomorphology and types (fringing reef, barrier reef, and atoll)
A. Watanabe and T. Nakamura