Threats to Sulawesi’s natural environment

Until recently, the Konawe karsts were generally well preserved, but in recent years they have come under a number of threats directly linked to human activity. The northern foothills of the Matarombeo massif have given way to palm oil plantations, parts of Matarape Bay are being razed by nickel mining companies, and the lack of a waste management system in the region is leading to heavy pollution of the ocean by plastic waste.

Some of the threats described on this page are already having a negative impact on the massif, while others will only really be felt in the medium term, if nothing is done to remedy them. While their scale can be frightening, it’s also good to know that there are ways of countering or limiting the impact of each of them.

Oil palm plantation in Sulawesi, Indonesia.
The area around the Matarombeo massif is threatened by the development of palm oil plantations.


The huge increase in both demand for and production of palm oil worldwide has led to an explosion in oil palm plantations in recent years. This development has largely been at the expense of primary forest, as on the islands of Borneo and Sumatra, where there was still a lot of primary forest just 20 years ago.

Far from stopping, the expansion of plantations is now reaching the east of Indonesia, including areas that were previously difficult to access and which are often the last reservoirs of species that have elsewhere disappeared. Sulawesi lost 11% of its forest cover between 2000 and 2017, and it is precisely the forest areas responsible for the island’s extraordinary wealth of biodiversity that are most at risk. In Konawe, the peripheral forests on the northern slopes of the Matarombeo massif are being nibbled away more and more each year by plantations. Other commodities, such as cocoa, pepper and sugar cane, also play their part.

It is also feared that the residues of phytosanitary products (pesticides and fertilisers) used on the plantations will run off into the rivers and then into the estuaries, where they will contribute to polluting and disturbing the mangroves and underwater ecosystems of Matarape Bay.

On the island of Sulawesi, it is estimated that 80% of the forests have disappeared over the last hundred years.

Deforestation and palm oil plantations. Matarombeo Massif, North Konawe, island of Sulawesi, Indonesia.
Deforestation and palm oil plantations on the northern slopes of the Matarombeo massif. North Konawe, island of Sulawesi, Indonesia.

Plastic pollution

The lack of infrastructure and environmental education in a densely populated country like Indonesia, which has also developed very rapidly in recent years, has led to the absence of waste management systems in many parts of the country. As a direct result of this situation, the country’s rivers are extremely polluted, and Indonesia is the world’s second largest emitter of plastic waste into the ocean.

The coastal area of the Bay of Matarape is no exception. Most of the waste from the villages is dumped directly into the sea, which, with the tides, currents and storms, scatters it along the shoreline. Plastic waste has many impacts on the environment: marine animals mistake it for food or become entangled in it, it causes disease in coral, and in the long term breaks down into micro-plastic pellets that take centuries to decompose.

Plastic waste pollution in Matarape Bay
Plastic waste is omnipresent on the coastlines of South-East Asia. Matarape Bay, Sulawesi.

Nickel exploitation

Indonesia has 15% of the world’s lateritic nickel resources (the same as in New Caledonia), demand for which is currently high due to the manufacture of batteries for electric cars. These deposits are located on the islands of Sulawesi and Halmahera. On the island of Sulawesi, the districts of North Konawe and Morowali, bordering the south and north of Matarape Bay respectively, are home to the largest deposits.

The coastline of Matarape Bay is home to dozens of open-cast nickel mines. Exploitation concerns the surface layers of the soil: once exploitation has been completed in an area, the forest has been razed, the soil no longer has any structure, cohesion or micro-organisms, and the adjacent seabed, which includes numerous coral reefs, is smothered under layers of red sediment. Sites that have been surface mined in this way are also the most difficult to reforest.

The mining companies exploiting the Konawe deposits do not install settling basins to hold back the flow of sediment (which is particularly heavy during the rainy season) and carry out almost no restoration work. Hardly any farmers preserve topsoil, the surface layer of topsoil, and return it to the land at the end of their operations, as required by law. Previously exported unprocessed, the ore has had to be processed on Indonesian soil since 2014, but many companies have obtained exemptions from this rule.

The districts of North Konawe and Morowali are home to considerable nickel ore resources, which could be exploited over several decades.

Nickel mining in Matarape Bay, on the island of Sulawesi.
Nickel mining in Matarape Bay, on the island of Sulawesi.

Acanthaster or« Crown of Thorns »

Commonly known as the Crown-of-thorns starfish (CoTS), the Acanthaster Planci starfish is a predator of coral polyps. In a healthy ecosystem, it plays a cleansing role by eliminating diseased corals or controlling the population of certain species over others. Extremely fertile, a single star can emit tens of millions of eggs in a single clutch, the vast majority of which do not survive.

For reasons that are still unclear (global warming, fertiliser run-off from intensive farming, coastal development and wastewater discharge, poaching of its predators, etc.), Acanthaster proliferation episodes are multiplying and wreaking havoc on coral reefs around the world. Several population explosions have been observed since 2017 in Matarape Bay.

While global warming and ocean acidification resulting from greenhouse gas emissions are one of the main threats to coral reefs around the world, infestations of Acanthasters are responsible for half of the decline in reefs, destroying them to the point where regeneration is now very difficult, if not impossible.

Acanthaster Planci or "crown of thorns" starfish
For reasons that have yet to be clarified, the starfish Acanthaster Planci or “crown of thorns” is proliferating. Matarape Bay, Sulawesi.

Uncontrolled tourism development

Still little-known, Matarape Bay has only two or three accommodation facilities and remains virtually untouched by visitors. But it’s only a matter of time before this sumptuous site, already dubbed ‘little Raja Ampat‘, is ‘discovered’ and appears on blogs, guidebooks and local travel agenc Local tourism development has already accelerated in 2018. Among the harmful consequences: tourist rubbish left on the beaches and boats dropping their anchors on the coral.

Ecolodge under construction in Matarape Bay.
Ecolodge under construction in Matarape Bay, Southeast Sulawesi, Indonesia. Construction of the lodge began in early 2018.

To ensure that the site is not disfigured by the unreasonable development of infrastructure, that the influx of tourists does not destroy the coastal and underwater ecosystems, and that the local population does not benefit from this development, it is necessary to take the leadby raising awareness among local populations of the richness and fragility of their environment and helping them to develop sustainable ecotourism that preserves their environment while providing them with an income. Tourism could then be one of the keys to a dynamic that benefits both the local population and the natural environment.

Coral reefs in Matarape Bay, Sulawesi, Indonesia.
Coral in Matarape Bay. The seabed, and particularly the coral, can be quickly damaged once tourism, and therefore the number of boats, increases. Matarape Bay, Sulawesi.

Unsustainable fishing

Dynamite fishing is very common in South-East Asia, as it is in Matarape Bay. This involves the fisherman throwing a homemade bomb into the water which, when it explodes, kills marine life indiscriminately within a radius of 50-70m, including juveniles, marine mammals and coral. A series of explosions on a reef makes regeneration very difficult. Despite the damage caused to underwater fauna and the risk of local fish stocks collapsing, this type of fishing can be very profitable in the short term.

Potassium cyanide is also widely used to catch live fish that are highly prized in Hong Kong and Singapore restaurants, such as Napoleon or grouper (see this excellent photo report and this movie photographer James Morgan on the Bajaus of Sulawesi and reef fish fishing). It causes nearby coral affected by chemicals to die back. Overfishing is also a problem, with industrial fishing boats (below) fishing illegally close to the coast, including in theoretically protected areas.

Fishing platform in Matarape Bay.
Fishing platform in Matarape Bay, Sulawesi, Indonesia. Local fishermen blame these platforms, some of which come from Makassar, the island’s capital, for overfishing and the decline in catches.

Cement factories

The karstic rocks themselves are also used industrially, for cement production. Previously protected by the forest, which made their exploitation costly, the disappearance of the forest and the construction of roads for oil palm plantations are making them increasingly vulnerable. Throughout South-East Asia, which has the highest quarrying rate in the world, one karst complex after another is exploited until the impressive vertical reliefs are nothing more than memories. This threat, although still remote for the Matarombeo karst, could one day become a reality if protective measures are not put in place within the next decade.

To find out more

Find out more about our initial conservation activities and our long-term strategy for preserving the Konawe karsts: Préserver les karsts du Konawe – Helloasso[tp lang=”en” only](French only)[/tp].

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English translation made possible thanks to the PerMondo project: Free translation of website and documents for non-profit organisations. A project managed by Mondo Agit. Translator: Cressida McDermott[/tp]