Status of Coral Reefs of the World 2000

Status of Coral Reefs of the Southern Indian Ocean
Mauritius
Relatively minor coral bleaching was observed in mid-February 1998 in the lagoons and on
outer slopes of Mauritius. Quantitative monitoring at 2 sites including Trou aux Biches from
March-May 1998 showed degrees of bleaching at all sites, with less than 6% of corals
totally bleached and 27% partially affected. Again Acropora species were the most
affected. No bleaching was visible after 9 months at the monitored sites, with all corals
apparently ‘recovered’ and the effects were much less than other IOC countries. Rapid
surveys at 36 sites around the main island and inner islands showed that the reefs in
Mauritius had suffered some bleaching in 1998, but most reefs were still healthy with the
main signs of damage from boat and anchor damage and cyclones. The only large areas of
dead standing coral were on the Barrier Reef off Mahebourg, and mean bleaching was less
than 10% at all sites, often seen as partial bleaching of colonies. Mauritius probably
escaped the mass bleaching event of 1998 because of cyclone Anacelle, which produced
wet and cloudy weather in February 1998.
La Reunion Island
No widespread bleaching has occurred over the past few years, and the major El Niño
event of 1998 affected less than 10% of the coral communities. Some bleaching was
observed in 2000 on the west side of La Reunion, but this appears to be related to
exposure during extreme low tides.
Seychelles
These reefs were amongst the worst affected in the Indian Ocean during the
unprecedented events of 1998. There was extensive coral bleaching and mortality starting
in February 1998 at the height of the southern summer and coinciding with the most intense
El Niño event on record. Bleaching ceased in May 1998 after seawater temperatures had
reached 34 o C. It is estimated that 40-95% of corals in the Seychelles were bleached, with
subsequent mortality of these varying from 50-95%, but the bleaching was not uniform
across the archipelago. The southern islands (Aldabra, Providence, Alphonse) had only 40-
50% bleaching, whereas it reached 95% mortality in the Ternay Bay Marine Park (Mahe).
Coral regrowth and new larval recruitment has now started and small colonies are evident in
various places, although the recruitment is still very weak reflecting the high mortality of
adult corals. The largest pool for coral larvae appears to be from deeper zones unaffected
by bleaching. If there are no further major bleaching events, these reefs should recover,
although recovery will be slow.
LEGAL INSTRUMENTS, MONITORING AND MPAS
Legal Instruments - Creation of ‘Coastal’ or ‘Reef’ Laws
There are no specific laws for reef environments in the IOC countries, although most have
legislation for coastal zones that could be applied to coral reefs. For example on La
Reunion, which is a French territory, the coastal law of 1986 recognises that ‘the coast is a
geographic entity needing a specific planning, protection and development policy’. The
decision to establish Schema d’Amenagement Regional (SAR or regional planning policy)
on La Reunion predates the coastal law, and has probably reinforced the ‘Schema de mise
en valeur de la Mer’ (SMVM or sea development policy) as the maritime arm of the SAR.
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