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

Status of Coral Reefs of the World: 2002
Sri Lanka
The healthiest reefs in Sri Lanka were those remote from human settlements prior to
1998, with coral cover estimated at 80% on coral reefs of the Bar Reef Marine Sanctuary,
more than 50% at Weligama on the south coast, and about 35% in the Hikkaduwa Marine
Sanctuary, also in the south. Most shallow reefs of Sri Lanka were destroyed in 1998
including reefs around the northwest to the east coast, except near Trincomalee. Coral
recovery is now variable. There were many small colonies of branching Acropora and
Pocillopora in the shallows of the Bar Reef Marine Sanctuary in early 2002, indicating
strong natural recovery. The number of tabulate Acropora colonies was higher than the
branching Acropora colonies in 1-3m depth, with the largest new Acropora colonies about
100cm in diameter and 35cm high. However, new growth of live coral is patchy and much
of the reef remains bare. The reef structure is largely intact due the growth of encrusting
coralline alga. Coral growth was better at 7-8m depth with more species and 14% live
coral cover (Acropora – 3.1%, plus Montipora, Favites, Favia, Pavona, Cyphastrea,
Hydnophora, Galaxea and Podabacea). Butterflyfish are still rare on the Bar Reef, and
some juvenile damselfishes were seen along with numerous herbivores (siganids, scarids
and acanthurids).
There has been a slight improvement in the live coral cover in the Hikkaduwa Nature
Reserve from 7% in 1999 to 12% in 2002, due mainly to an increase in Montipora species
which escaped the bleaching. The only other coral survivors are the sediment tolerant
species such as Favia, Favites, Montastrea and Porites. No new Acropora recruits were
seen in 2002. A reef on a nearby limestone platform had much higher live coral cover and
different species, including Porites (4.4% cover), Acropora (3.9%), Favites (2.4%),
Montipora (1.3%) and Platygyra (1.2%).
The shallow reef at Kandakuliya, south of the Bar Reef Marine Sanctuary has been
completely overgrown by Halimeda algae killing almost all the new coral recruits seen in
2001. The Rumassla (Buona Vista) reef in the south had 19.6% coral cover and recovery
Cover of live corals on reefs in Sri Lanka before and after the 1998 bleaching mortality, showing the
extent of damage, with some recovery.
Location Depth Pre-bleaching- 1999 – 2000 2001-2002
(m) live coral cover live coral cover live coral cover
Bar reef 0-3 78.5% overall Nearly 100% mortality Some new colonies;
in 1993-1994.
too few to measure
cover.
Bar reef 7-8 Nearly 100% mortality 14%
Kandakuliya 0-5 22% Small colonies present Corals smothered by
Halimeda.
Hikkaduwa Nature 0-4 47.2% 7% 12%
Reserve
Hikkaduwa, South 7-13 Not estimated Not estimated 17%
of Nature Reserve
Rumassala 1-5 45% 19.6% Better recovery at 4-5m;
cover not estimated
Weligama 0-2 92% 28.0% 54%
31.04%
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