Mangroves are a crossroad where oceans, freshwater, and land realms meet. They are among the most productive and complex ecosystems on the planet, growing under environmental conditions that would just kill ordinary plants very quickly. In general, mangroves have specialised root structures (breathing roots or pneumatophores) as a result from their physical adaptation to oxygen-poor or anaerobic sediments/soils.
Roles and benefits of mangrove forests:
To protect coastal areas from coastal erosion and abrasion.
- To protect coastal communities from the impacts of severe storms and cyclones.
- To prevent seawater intrusion.
- To be a sanctuary or habitat for various fauna such as fish, shrimps, crabs, waterbirds, monkeys, etc.
- To provide valuable natural resources such as construction wood, shipping wood and wood fuel.
- To have educational and recreational potential.
- To mitigate climate change through CO2 sequestration.
Impacts and causes of mangrove degradation/loss
Degraded and loss of mangroves has caused coastal abrasion, sea water intrusion, flood, loss of settlements due to storm, loss of natural fishing areas, and opportunities to mitigate greenhouse gas emissions.
The above conditions are generally caused by:
Over-harvesting of wood from mangrove forests.
- Conversion to aquaculture.
- Unsustainable urban and agricultural development.
- Neglected deforested mangrove areas.
Indonesia has large coastal zones which are rich with various coastal vegetations such as mangrove forests (the country, in fact, has the largest mangrove forests in the world with an area of 3,2 million hectares). Unfortunately, since the mid-1980s, a large part of Indonesia’s coastal zones has been severely damaged due to conversion to aquacultures and other purposes.
To reverse the functions, values and environmental services of mangrove forests and other coastal ecosystems, there is a need to restore and to implement sustainable coastal zone management. One of them is through the silvofishery concept, which combines the replanting of mangroves near and inside shrimp and fishponds.
Benefits from sustainable aquaculture practice:
- The construction of embankment ponds will become stronger because it will be supported by mangroves roots.
- Passer-bys can walk comfortably along the embankments as they will be protected from the sun by the canopy of mangrove forests.
- Mangrove leaves can be used as cattle feedstock (especially for goats) and its fruits can be made into jam, crackers, etc. for human consumption.
- Increased biodiversity, particularly fish and crab species will increase the income of local fishermen.
- The prevention of coastal erosion and sea water intrusion provides security to human settlement and sustainability of freshwater resources.
- Water quality of aquaculture will become better because mangrove roots can filter solid waste while the micro-organism found on the floor of mangrove forests can decompose organic materials from inside and outside aquaculture activities.
- The formation of coastal greenbelt not only will protect the coastal settlement from sea level rising, but also support climate change mitigation and adaptation programme because mangroves sequester CO2 from the atmosphere.
- Mangroves will reduce the impacts from natural disasters such as storms and tidal waves so that business activities and the surrounding human settlements can be salvaged.