Status of Coral Reefs of the World 2000

Status of Coral Reefs of the World: 2000
Solomon Islands) because of extensive logging, poorly planned agriculture, uncontrolled
coastal development, and mining. The major threats to the marine environment throughout
the Pacific Islands are summarised below:
• nutrients from sewage, soil erosion and agricultural fertilisers;
• increased sedimentation from poor land use;
• physical alterations through destruction of fringing reefs, beaches, wetlands and
mangroves for coastal development and sand extraction; and
• over-exploitation of coastal food fisheries, particularly through destructive fishing
methods.
Most of the population lives in the coastal zone, and in atolls like Tuvalu, all livelihoods are
coastal based. Rapid growth of these coastal populations is responsible for much of the
plundering of coastal resources, destruction of mangroves, pollution of lagoons and
harbours, and loss of some marine species and ecosystems. Some of the damage is now
irreversible, e.g. coastal modification and destruction of habitats, and this will increase in
the future, if population growth continues unabated. Land based sources of pollution are
among the greatest threats to marine biodiversity. Marine invasive species are poorly
documented, but may pose a threat near ports, harbours and coastal habitats. Shipsourced
marine pollution is also a potential threat.
Tourism is the most rapidly growing industry in parts of the region (e.g. Fiji, Samoa and
Vanuatu), with a large proportion of these tourists being divers. Construction of tourism
facilities has accelerated erosion in some areas and caused sedimentation on reefs and in
CROWN-OF-THORNS STARFISH
Population explosions of the coral eating crown-of-thorns starfish (COTS, Acanthaster
planci) have been a major problem on many coral reefs, such as the Suva Barrier Reef, Fiji
since 1979. While human activities have been blamed for these outbreaks, they may also
reflect long-term natural variations in the populations or consequences of climate events
like El Niño events. However, there is evidence that eutrophication and siltation
encourage larval survival and enhance the proliferation of the animals. Heavy infestations
cause major changes in coral communities and have the potential to shift species diversity
because they target the branching corals of the species Acropora and Pocillopora. Major
outbreaks were observed in 1986, 1988 and 1997 on Suva reefs. In 1996, the
Mamanuca group was affected and was followed by a moderate outbreak in the Kaba area
in 1997. In 1998 the Wakaya and the Lau Group reefs saw a large aggregations of
COTS, as were Taveuni and the Somosomo Strait the following year. Early this year Cuvu
Reefs on the Coral Coast were affected by COTS and villagers collected over 2000
COTS for a one-km stretch of reef. Current reports from August to September 2000,
indicate large numbers of COTS aggregating near the Solo Lighthouse Reef in the Great
Astrolabe Reef. There has been a recent outbreak around Noumea, New Caledonia, and
there was a clean up at major dive sites; 1,500 were collected from Tabu reef, and 1000
from Ilot Maitre. These are the first outbreaks for at least the last 10 years.
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