CORDIO Status Report 2002.pdf

Executive Summary
Since the 1998 coral bleaching and mortality, which
affected reefs throughout the tropics, a number of
projects dealing with research, monitoring and management
of coral reefs have been conducted. A number of
these projects have been carried out under the CORDIO
Program in the Indian Ocean where coral reefs have
been severely impacted by bleaching related mortality
and other anthropogenic influences. This, CORDIO’s
third status report, describes the condition of coral reefs
throughout the central and western Indian Ocean and
presents the results of several targeted research projects
conducted within the last 18 months.
The Recovery of Coral Communities Including Fish
The covery of coral reefs is highly variable between sites
in East Africa and South Asia. Generally, extensive mortality
affected the islands of the northern and central
Indian Ocean (Maldives, Seychelles, Aldabra, Chagos), the
East African coast (Mozambique, Tanzania and Kenya),
Sri Lanka and parts of India. Islands of the southern
Indian Ocean (Reunion, Comoros, Mauritius, Madagascar)
were not seriously affected. In most of the areas
that suffered high coral mortality (i.e. more than 50%),
recovery is slow, patchy or non-existent. In some areas,
significant recovery appears to be underway. However,
such areas are usually located far away from human
influence or are well protected in marine reserves. It is
obvious that in many places closer to human habitation
other stresses from anthropogenic activities, such as destructive
fishing, coral mining and sedimentation from
land, continue to degrade the reefs, slowing down or
preventing recovery from the 1998 bleaching event.
TANZANIA
Little recovery was observed on the reefs of Misali Island
where 80% mortality was noted in 1998. Similar observations
were made on Kwale and Mafia reefs where the
cover of live coral remained low or continued to decline.
Chumbe Island and the reefs off Zanzibar town were
relatively unaffected by the 1998 bleaching event. However,
destructive fishing and outbreaks of Crown of
Thorns starfish are now affecting several of these reefs.
Fish populations showed significant changes and several
groups (especially invertivores, piscivores and plaktivores)
decreased while other groups (particularly herbivores)
increased. During 2001–02, harmful algal blooms
and an unknown fungal coral disease have impacted
reefs in northern Tanzania. These stresses may be climate-change
related. Over-fishing, destructive fishing,
pollution from human settlement and development,
mining and shipping industry activities continue to
cause degradation to the reefs of the country.
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