Indonesia is the largest archipelagic country in the world, with more than seventeen thousand islands extending it's seas. Around 80.000 kilometers of coastline are surrounded by tropical seas that contribute to the country's high level of biodiversity. Being part of the coral triangle, Indonesia is home to the world's greatest diversity of coral reef, with 20% of the world's coral reefs, over 3,000 different species of fish and 600 coral species.

 

The vast diversity of coral reefs in Indonesia has contributed significantly to the country's economic development. Many Indonesian fishermen depend on coral reefs because many fish spawn around the corals. Moreover, juvenile fish spend time among the corals before making their way to the open sea. Aside from fisheries, Indonesian income is also generated from marine tourism activities.

 

Coral reefs are important because in addition to contribute to the economy, coral reefs have many other uses, such as to protect coastlines from the damaging effects of wave action and tropical storms, provide habitats and shelter for many marine organisms, being the source of nitrogen and other essential nutrients for marine food chains, assist in carbon and nitrogen fixing, and also help with nutrient recycling.

 

Despite the importance of coral reefs, these wildlife habitats are imperiled. Recent reports estimated that 80% of Indonesia's coral reefs are currently threatened. Even some of the most remote and pristine reefs are losing species.

 

Rising seawater temperature as a result of global warming is one of the most serious causes of stress to corals throughout the world. When temperatures are too high, the relationship between corals and their symbiotic microalgae breaks down. When the algae that are what gives corals some of their bright colour went out, corals appear white or "bleached". If the temperature is too high for a long period of time, corals and their microalgae are unable to recover. Over the past 30 years, bleaching has become more frequent, more intense, and more widespread. This has led to massive die offs of corals throughout the world.

 

Another issue for coral life is Carbon Dioxide. As more carbon dioxide (CO2) is released into the atmosphere, it also has adverse effects on the oceans. Recently, ocean acidification has emerged as another potentially serious threat to coral reefs. Seawater adsorbs some of the excess CO2 from the atmosphere, causing the oceans to become more acidic. As a result, the oceans' acidity has increased by 25 percent over the past 200 years. These acidic conditions dissolve coral skeletons, which make up the structure of the reef, and make it more difficult for corals to grow. If left unchecked, scientists estimate that the oceans could become 150 percent more acidic by the end of this century, making it very hard for corals to grow at all.

 

Coral reefs are also being degraded by many other factors caused by human activities. The list of problems can seems endless: overfishing, fishing using cyanide and dynamite, pollution from sewage and agriculture, massive outbreaks of predatory starfish, invasive species, an sedimentation from poor land use practices.

 

Reefs and their wildlife across the world are also affected by destructive fishing and exploitation to supply the coral reef wildlife trade. Fish, corals, and various invertebrates are all taken from reef habitats to serve as aquarium pets or decorative items. Although this trade can be conducted sustainably, wildlife populations are often overexploited to feed the demand for these animals. Sometimes poisons like cyanide are dumped into the water to stun fish and make them easier to capture. Sadly, fishing with cyanide often kills fish, corals, and other form of wildlife, while degrading the reef habitat itself.

 

Over exploitation of marine resources are often given a lower priority due to high poverty levels and weak, under-resourced governments.

 

Marine tourism is a major economic importance for Indonesia. Since Indonesia is part of the coral triangle with a high diversity of coral reefs, there have been and continue to be impacts from tourism on the coastal environment, including the coral reefs itself.

 

Tourism has both direct and indirect impacts on coral reefs. Snorkeling, diving and boating can cause direct physical damage to reefs. The damage inflicted by divers and snorkelers consists mostly of breaking fragile, branched corals or causing lesions to massive corals. Training and briefing of divers and snorkelers will greatly help to reduce negative impacts.

 

While physical damage from anchors and especially boat groundings can be severe. Anchor damage is proportional to the size of the boat and is further dependent on the type of coral community. Anchor damage can be avoided to a large extent by installing permanent moorings, designating anchorages and providing adequate information on anchoring and mooring.

 

Indirect impacts relate to the development, construction and operation of tourism as a whole. There is evidence that a very large percentage of the sewage generated by hotels is discharged in coastal waters without adequate treatment. The main impact of sewage pollution is nutrient enrichment, which favours certain species at the expense of corals.

 

Coastal development and the construction and operation of related tourism infrastructure cause increased runoff and sedimentation. Increased sediment loading of coastal waters increases turbidity, reduces light levels and leads to stress on corals. Heavy sediment loading may also cause corals to suffocate and die. Other documented impacts of sedimentation on corals include lower growth rates, reduced productivity and reduced recruitment.