CORDIO Status Report 1999.pdf

Various corals in Chagos, 1999. A: A massive Lobophyllia corymbosa coral from Diego Garcia lagoon. Red disks are still-living polyps. B: A massive
faviid coral, now unidentifiable. Dead part has eroded about 1 cm. C: Close up of edge of a table coral, showing eroding and crumbling tips. D: Large
whorls of Echinopora lamellosa, mainly dead, but with some live tips to some of the leaves. Photos: C. Sheppard.
A
B
C
D
6. Recovery
There is little information on how long it may take for
reefs to recover, but reef recovery on a much smaller
scale clearly takes many years or centuries. The suggestion
that this is a “natural event’’ merely dodges the
issue, and may only provide a refuge in which to avoid
finding a solution. It might be true that it has happened
before – a century ago no reef monitoring took place
anyway – but many of the coral colonies that were killed
are around 200–300 years old. So clearly, this scale of
mortality has not occurred within that time frame.
7. Alternative stable states
Several examples show that if a reef is stressed and
changed, and the stress is removed, the reef may not
necessarily revert to its original condition. In part, this
appears to depend on the severity of the stress. Good
examples of this exist in the Caribbean and Indian
Ocean. When corals die, they form fragments which are
abrasive and inhibit new coral settlement and growth,
exacerbating the situation. The long-term prognosis of
the 1998 coral mortality may therefore be very poor.
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