PROJECT: Help restore the ecosystem on Koh Samui, Thailand
The Reearth team is conducting a reef survey with the local fishermen.
It is high time for us travelers to give back to the destinations we love. We all know that tourism is essential for the economy in many areas around the world.
Tourists are needed as well as a healthy environment. Sustainable tourism is the only way forward.
The problems
Reefs in tropical coastal waters surrounding populated coasts and islands, like Koh Samui and its neighboring islands, face a big problem – rural development and agriculture.
This heavily affects the tourism and fishing industry, which is the backbone in the local economy.
The worst case scenario for many places like Koh Samui, Koh Tao, Koh Phangan is that tourism decreases at the same time as the coastal fishing disappears.
When it rains there is no vegetation and root system to keep the water from flushing away the soil By planting grass with stronger root system in the worst areas like slops the land becomes more resistant to heavy rain.
With development taking place, a lot of the natural plant life vanishes. With the plants vanishing – along with their root systems that maintain the moisture in the ground – the land turns dry and arid. When it rains there is no vegetation and root system to keep the water from flushing away the soil. This causes floods on lower elevations that also cause sediment and soil to be washed into the sea. For every monsoon, there is less and less soil left for the plants to grow in and the subsequent rain erodes the ground even more.
Due to erosion excessive amounts of sediment and soil ends up on top of the corals. The result is devastating. The coral’s oxygenating algae suffocates and finally the reef dies and along with it its fragile ecosystem.
One of the solutions to erosion is to build small dams to prevent the rain water from running straight down to lower altitudes most effective when built in a row of connecting small dams.
REEARTH THE SOLUTIONS – LAND
An extremely simple way to take control of the above described problem with many positive side effects for nature and people alike – starts on the high altitude of Koh Samui’s mountains in the natural forest. The solution is to build small dams to prevent the rain water from running straight down to lower altitudes. The small dams can be built in various sizes, the main ones being the “small” one (about 5-10 x 5-10 m) and the “big” one (about 10-20 x 10-20 m). The dams are most effective when built in a row of connecting small dams together with a big dam. They are mainly made from natural material and are very inexpensive and easy to build. The method is used in many parts of the world with great success and is called different things depending on its main purpose; check dams, rainwater harvesting dams. These dams make the water flow much slower (evidently) after a rain, through tiny perforations in the structure. When the water is kept from running straight down to lower altitude, and instead, manipulated by a dam to slowly ooze like a mini creek, the benefits are multiple:
When the water is kept from running straight down to lower altitude, and instead, manipulated by a dam to slowly ooze like a mini creek the benefits are multiple.
• Decrease of erosion, floods and landslides – The dam lets the water stay put, to ooze into the arid soil, moisturizing it and thus benefiting plant life. With more plants growing, there are more roots to keep the moisture naturally, and more root systems to prevent sediment from leaving the ground and running out into the sea to suffocate the coral reef. No more coral reef suffocation.
• Water for locals – During dry season, which is also the busy tourist season only small quantities of low quality water is available. These dams’ increases the level of groundwater which is essential for the whole island and a very urgent problem. The water shortage in the dry season can be severe. These dams can also provide many households with clean drinking water throughout the year, like a well.
Hydroelectric power stations are suited to provide one or two households each with electric power.
• Electricity - The Green Island Project on Koh Samui is trying out prototypes of small hydroelectric power stations, suited to provide one or two households each with electric power. Many local families in the mountain areas of Koh Samui are using expensive and polluting diesel powered generators. These dams can be sufficient to power the surrounding and local households with clean and small hydroelectric power stations.
• Agriculture. The moisturizing effects of this solution, also give the locals a soil which they can use for agricultural purposes, such as growing durian fruits (common on Koh Samui). This can be a good source of income for a poor family. The Green Island Project on Koh Samui has so far built almost 700 small dams. The target is 8000 small dams to eliminate the many problems caused by the effects of erosion.
The moisturizing effects of this solution gives the locals a soil which they can use for agricultural purposes but also nurseries for plants that is part of the solution to fight erosion.
The local Green Island Project is our main partner in solving the many dilemmas caused by erosion. Together with the local Forest Ministry the Green Island Project will be in charge of implementing the work in regards of the dams.
Costs example: one big dam with a capacity of more than 500 cubic meters and more than 50,000 cubic meters of underground water reserve costs approx. 10,000 SEK or 50,000 THB including material and labour. No additional administrative costs.
REEARTH THE SOLUTIONS – OCEAN
We have dead reefs surrounding the island. How do we rejuvenate them?
Coral reefs need some kind of structure to form and grow on. They can’t just emerge from the sand once they are gone. Natural coral reefs usually grow on natural formations, such as rocks and pinnacles. But coral also grows on items that has been left (intentionally or not) in the sea by humans, such as shipwrecks or artificial reefs.
Coral reefs need some kind of structure to form and grow on they cannot just emerge from the sand once they are gone.
Artificial reefs (ARs) have a long tradition in many parts of the world. In recent years the use of modern materials has greatly increased their potential. E.g. the use of purpose-built building blocks, modules, constructed from cement or steel.
Regardless of construction method, artificial reefs are generally designed to provide hard surfaces to which algae and invertebrates such as barnacles and corals attach; the accumulation of attached marine life in turn provides intricate structure and food for varieties of fish.
For the artificial reefs to contribute to sustainable fisheries in the longer term, it is important that the fishing communities are involved in all steps of the decision-making and development processes. They will participate in the selection of the reefs’ sites, the choice of materials, the management, monitoring of the reefs and evaluation of the reefs. It must be the community’s decision whether to proceed or not at each stage of the process. The Samui Mermaid Group is our main partner for implementing the solutions. The Samui Mermaid Group consists of 180 local fishermen who work closely with the Department of Marine and Coastal Resources.
In recent years the use of modern materials has greatly increased the artificial reefs potential the use of purpose built building blocks or modules constructed from cement or steel.
The method of choice – large cement blocks placed in a row – is tried and tested locally and is both simple and inexpensive. No coral needs to be “planted” as the neonates of these creatures flow naturally from far away with the ocean currents, and attach themselves to any appropriate surface they come in contact with and, if conditions are good, they start reproducing to form a coral reef in approximate 3-5 years. Nurseries for fish start earlier.
Costs example: 200 meters of simple artificial reef, made from round hollow cement blocks costs approx. 30,000 SEK or 150,000 THB including material and labour. No additional administrative costs.
