2,220 kg/year for the similar zonation in 2100 after a 0.5 m
rise. After a rise of 1.8 m, by contrast (Figure 2), the carbonate production rate across the reef flat was 4,950 kg/year
and the reef flat zonation highly modified with much of
the active coral growth having moved shorewards.
Hopley et al. (2007) also undertook a similar exercise
for a >3 km wide reef top typical of some GBR planar
reefs Again, calcium carbonate productivity was increased
only marginally by a rise in sea level of 0.5 m. However it
was more than doubled by the larger rise as the reef top
was rejuvenated. In both instances water levels would rise
over the reef flat, laterally transporting much of the new
material towards leeward cays, or lagoons. This would
be especially so if a large proportion of the new growth
Climate Change: Impact of Sea Level Rise on Reef Flat Zonation and Productivity, Figure 2 Modeled atoll reef flat and response to
a sea level rise of 0.5 and 1.8 m by, 2100 (from Hopley, 1997).
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CLIMATE CHANGE: IMPACT OF SEA LEVEL RISE ON REEF FLAT ZONATION AND PRODUCTIVITY