Coral Reef Death ..

CORAL REEF DEATH LINKED TO TROPICAL
WILDFIRES IN INDONESIA DURING THE 1997
INDIAN OCEAN DIPOLE

N.J. Abram (1), M.K. Gagan (1), J. Chappell (1),
M.T. McCulloch (1), W.S. Hantoro (2)

The coral reefs of the Mentawai Islands, Indonesia, experienced catastrophic mortality of close to 100% of the coral and the fish during the 1997 Indian Ocean Dipole (IOD) upwelling event. The link between elevated sea surface temperatures (SST) and coral death is now well known, however the unanticipated Mentawai reef mortality coincided with anomalously cool SSTs and a giant red tide. Ocean productivity in the Indonesian region is generally proportional to the strength of upwelling; therefore the severity of the 1997 Mentawai reef death raises the question of whether the magnitude of the IOD upwelling and red tide during 1997 was unprecedented. Here we examine the tolerance of Mentawai corals to IOD upwelling events over the past 6,300 years using coral skeletal growth and palaeothermometry. High-resolution coral Sr/Ca and 18O reconstructions of SST reveal pre-historic IOD cold anomalies of up to 5.8C.

The magnitudes of these events exceed the strong 1997 IOD upwelling by as much as 1.9C, yet we find no evidence of past coral mortality. From these results it seems that the intensity of the 1997 Mentawai red tide was much greater than expected based on the magnitude of IOD upwelling alone. This implies that an additional source of nutrients must have supported the catastrophic red tide and we propose that these nutrients were provided by the 1997 Indonesian wildfires. These fires were the worst in south-east Asian history and were the combined results of land clearing, past forest disturbance and intense drought driven by the 1997 El Niño-Southern Oscillation and Indian Ocean Dipole events. Using mass balance calculations we show that ironfertilisation of the upwelled nutrient-enriched water by atmospheric fallout from the 1997 wildfires was sufficient to produce the extraordinary red tide, ultimately leading to the unprecedented death of the Mentawai reefs. These findings highlight the escalating phenomenon of tropical wildfire as a potential new threat to coastal marine ecosystems.

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(1) Research School of Earth Sciences, The Australian National University, Canberra ACT 0200, Australia, (2) Research and Development Center for Geotechnology, Indonesian Institute of Sciences, Bandung 40135, Indonesia.

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Raja Ampat Islands Contain World's Richest Coral Reefs

Some of the most experienced marine scientists tropical, led by The Nature Conservancy, conducted a three-week expedition to the Indonesian islands of Raja Ampat, where they confirmed that the region contains the richest coral reefs the world.

The Raja Ampat islands west of Sorong, on the northwestern tip of the island of New Guinea in the province of Papua in Indonesia. The four main islands - Waigeo, Batanta, Salawati and Misool - and their thousands of satellite islands cover an area of some 23,630 square kilometers (61200 square kilometers).


Scientists have found that the number of reef fish and coral species in the region is even greater than expected. At least 465 species of coral have been recorded, with at least 20 species to defy identification and study in others. This brings the total confirmed corals of the Raja Ampat islands to 505 species, an incredible 64% of all species of coral in the world (for the most recent estimates of numbers, see our report of the investigation in 2006 on the ).

During this trip, 828 species of fish have been recorded, adding an additional 95 (including four new to Indonesia) and increasing the total known to Raja Ampat to 1065 species - among the highest in diversity the world. A new personal record of 284 species of fish on one dive was set by Dr. Gerry Allen Kofiau to the island. When laboratory results on marine samples are completed, scientists expect to find species of fish and corals that are new to science.

"The waters around the Raja Ampat islands teeming with a diversity of corals and fish than anywhere else in the world," said Steve McCormick, president of The Nature Conservancy. "This place is at the heart of the heart of marine biodiversity, and every effort must be made to retain it."

"While we continue to see reports decimated and degraded marine ecosystems and in the west of central Indonesia, the survey clearly demonstrates that it is still a chance to retain important island of high quality and reef ecosystems in Indonesia, "said the conservation of Indonesia Country Director, Dr Ian Dutton. "Conservation is working in partnership with local communities and government, universities and industry partners to protect this wonderful region."

Raja Ampat has become an administrative region or kabupaten, and it is feared that the need to increase local revenue will allow the widespread extraction of natural resources. The results of this study marine and maps will be presented to local communities to raise awareness of the richness of biodiversity that the region has and solicit ideas on how best to keep it. It will help the local government establishes environmentally sensitive development plans, and contribute to the conservation and other conservation organizations to determine the best way to protect this remote tropical paradise.

"The customary ownership of resources and traditions of the region means that some reefs have escaped the ravages common to many other reefs of South-East Asia," said Dr. Rod Salm, director of the conservation of coastal marine conservation in the Asia-Pacific. "It's really an excellent opportunity to develop a conservation program with communities that have a strong personal and historic commitment to manage their resources sustainably."

Scientists have found many Raja Ampat coral reefs to be in good condition despite the rampant destruction reefs often seen in Southeast Asia. Parts of reefs damaged by the blast and cyanide fishing has shown a good recovery, and there was little evidence of the extensive coral bleaching that devastated reefs in many parts of the world following the 1998 El Niño. The fact that coral bleaching resisted confirms their resilience and value as a source of larvae to assist in the recovery of damaged reefs widely throughout Indonesia, Philippines, Papua New Guinea and Micronesia .

The team also noted a virtual absence of sharks during the trip - only three sharks were seen in 500 hours under water. Over fishing has caused a sharp drop in the Raja Ampat population of sharks. Shark fins are highly valued as a soup ingredient in Asia. There are about 200 shark-fishing boats operating in this area, and each is estimated catches of 240 per month. Once the fins are removed, the bodies are left to rot on the reefs. The removal of the ecosystem of predators is only one of the adverse effects of human activities on reefs - The buzz of chain saws, the crash of falling trees, and the bombing and cyanide fishing still widely practiced, and turtles are overexploited for each location they nest.

Ground crews have found many unique habitats in Raja Ampat, especially the broken-bottle limestone karst landscape, and rich mineral soil the northern islands. Around these islands in the extreme habitat has led to high levels of endemism - that diversity is low, most species of plants are found only in this particular habitat. Several potentially new species of plants were discovered, including a new species of flowering plant tropical Psychotria Kawe on the island.

Local communities are very concerned about damage to their environment on the whole, they depend on marine resources for their livelihood. Extractive industries such as logging and commercial fishing threaten to destroy the rich diversity of plant and animal life in these remote islands. Still, researchers on the socio-economic team was told by villagers that they feel powerless to counter the raiders outside resources that are more damage because they are often supported by powerful commercial and government interests.

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