#Status of Coral Reefs 2002 - International Coral Reef Action Network

Status of Coral Reefs of the World: 2002
abundances may reflect a regional pattern whereas the eastern islands around Praslin have
more fish e.g. only 2 large predators and 1 butterflyfish were recorded at Middle Reef.
Coral cover was low at all 3 sites on St Anne with limited coral recruitment. The highest
coral cover (15%) was on the reef-slope at Cerf, followed by Moyenne and Anse Cimetière
(10%). Sedimentation from the reclamation sites is probably the most important factor
limiting coral recruitment at Cerf, and considerable damage is apparent near the sediment
plumes. The algal cover differences between the sites reflects the degree of wave exposure;
Cerf 1 is sheltered, and the other 2 sites are more exposed. The high abundance of plankton
feeding damselfish is related to the nearby St Anne Channel which supplies more plankton.
Silhouette is a new site since 2000. The reef flat is heavily impacted by the south-east
monsoons and always has low coral cover e.g. no Acropora, and 9% cover of other corals,
plus some soft zoanthids (Palythoa). The outer slope has a mix of live and dead massive
corals (>15%), sub-massive corals (>15%), some encrusting corals, and 0.7% branching
young Acropora. This area appeared to be unaffected by the 1998 El Niño bleaching,
possibly due to the proximity of cooler, deeper waters.
The Curieuse island reef slope has 26% coral cover at Anse Papaie, 31% at Coral Garden,
whereas the reef flat at Anse Papaie had only 2.5% coral cover. Acropora corals were in
low abundance. No target fish were recorded on the reef slope of Anse Papaie, whereas 1
predator and 5 butterflyfish were recorded on the reef slope, but more were recorded at
Coral Garden (16 predators and 12 butterflyfish).
The Oasis 1 site on Alphonse island has 57% coral cover with some of the rare blue coral
Heliopora (0.8%) but no Acropora, or bleached corals. Fish abundances are high, with 24
large predators and 10 butterflyfish being recorded. Most of the corals are massive, including
a high proportion of species that are known to resist coral bleaching (e.g. like 1998). The
high fish abundance is probably related to the low fishing pressure and high coral cover.
RECOVERY FROM THE 1998 CORAL BLEACHING AND MORTALITY EVENT
Coral bleaching and mortality in 1998 was more severe in the Seychelles and Comoros
than in the south (Madagascar, Mauritius and Reunion), where there was recovery of the
bleached corals within a few months. Since 1998, there has been localised bleaching in
Reunion (2001), and on Rodrigues and Seychelles (March 2002).
On the Comoros in 1998 there was 50% bleaching on the former pristine reefs of Moheli,
and 40 to 50% coral bleaching at Mitsamiouli, with Acropora species worst affected. In the
last 4 years there has been a significant recovery in Moheli (Marine Protected Area of
Mohéli – Nioumachoua) e.g. the Candzoni site was heavily damaged in 1998 and now
shows a recovery to 41% from 20% in 4 years. A major pulse of new coral recruitment was
observed in the 2002 survey, particularly on the outer slope. There is Sea Surface
Temperature monitoring on Mayotte using automatic data loggers.
On Mauritius, there was relatively minor coral bleaching in the lagoons and outer slopes
in 1998, probably because cyclone Anacelle produced wet and cloudy weather in February.
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