While travelling in South East Asia, we stayed on many small islands. Koh Phangan, Koh Chang, Koh Rong Sanloem, Gili Air and most recently on Camiguin.

I love islands. The 360 degree surroundings of the sea give an ultimate exotic feeling. I am not the only one. Islands and coastal areas in South East Asia are popular and with the rise of tourism, the paradise areas have slowly turned into densely populated spots. Sometimes, the surrounding sea is also full of colourful fish and bustling with corals, a true magnet for tourists and a precious natural resource.

However, corals and their habitat are fragile. Not only do they break if carelessly touched or stepped on, they are also sensitive to the chemical composition of the water.

Poor in nutrients, rich in diversity.

Clear water, the one great for snorkelling and diving, is poor in nutrients and organics. Complex communities like corals grow slowly, and therefore develop into diverse communities that co-operate to share the few resources available.

When water gets richer in nutrients and organics, the fast growers, algae and bacteria, get an edge and overtake the slow growers. Water ceases to be clear, instead it becomes green/brown tinted. As oxygen concentrations drop, corals die and fish leave – dead zones are created.

Tourism and wastewater.

As tourists come flooding the favourite spots, numerous restaurants and resorts start popping up on the coast. The closer to the beach, the more attractive they are. There are laws preventing building too close to the coast, but under the rule of a corrupt government, an exception to the law can be bought. Thus concrete replaces sand and luxury resorts and hotels begin to fill the coast. Air conditioning, majestic view, swimming pool and, although unseen, huge septic tanks to collect the guests’ waste.

Septic tanks are containers located under the ground, and in some places they collect water only from the toilets, and in other places also from the showers and washrooms. The solids settle and are anaerobically decomposed into fatty acids and methane. As soon as they fill up, more incoming water will trickle out of the tank into the surrounding soil or sand.

Sewage pollution is shockingly widespread: A full 96 percent of places that have both people and coral reefs have a sewage pollution problem, according to recent research by Stephanie Wear, The Nature Conservancy’s lead scientist for coral reef conservation. (Source: nature.org)

Thinking of sleeping near the beach?  Think twice. Wastewater is rich in nutrients (P, N and C). And tourists produce a lot of wastewater which trickles straight into the sea. Especially if the septic is near the shore and at low tides. The wastewater you have produced is lethal to the sea life which you came to observe here. The crystal-clear water, so inviting to dive into, will fade and turn into an algal-bacterial soup.