Vital role of wetlands in battle against climate change

Today is World Wetland’s Day with this year’s theme being Wetlands for Disaster Risk Reduction.  A wetland or marshland as we know it in Sri Lanka, is a land area saturated with water, permanently or seasonally. Thus it becomes an important ecosystem. The primary factor that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation of aquatic plants, adapted to the unique hydric soil. Environment scientists say wetlands play several roles in the environment, principally water purification, flood control, carbon sink and shoreline stability. Wetlands are also considered the most biologically diverse of all ecosystems, serving as home to a wide range of plant and animal life.   

World Wetlands Day is celebrated on February 2 every year to mark the 1971 adoption of the Convention on Wetlands in the Iranian City of Ramsar. The aim is to raise awareness and highlight the vital roles of healthy wetlands in reducing the impact of extreme events such as floods, droughts and cyclones on communities and in helping to build resilience.   

Environmental scientists say coastal wetlands act as a natural protective buffer and thus it is important for Sri Lanka. Inland wetlands act as a natural sponge, absorbing and storing excess rainfall and reducing flooding. During the dry season, they release the stored water, delaying the onset of droughts and reducing water shortages.   

Wetlands can also speed up the recovery and help to “build back better” after a disaster, acting as natural water filters and nutrient restorers. For instance, after a 1999 cyclone that hit Odisha in eastern India, rice paddies that were protected by mangroves recovered their food production capability much more quickly than croplands which were without the buffer.   

At Hikkaduwa, where offshore coral reefs are protected through a marine park, the damage from the 2004 tsunami extended just 50 metres inland. In nearby Peraliya, where coral mining had degraded the reefs, the damage extended 1.5 kilometres inland, scientists point out.   

Now that we know about the importance of wetlands and the vital role they play in the battle against climate change, global warming and the natural disaster they bring, we need to be also aware of the extent to which the wetlands are being destroyed and what we could do to protect them. According to reports we have received, Sri Lanka’s wetland eco-systems are threatened mostly by legal or illegal landfills -- intended for agricultural and infrastructure facilities such as highways. Hard waste and waste water in urban and semi-urban areas are released into marshlands and internal waterways. This causes filling and pollution in wetland eco-systems. Sometimes land is acquired by cutting down trees in wetlands. Overuse of abundant natural resources as sand and clay destroy the system as well as collecting plants and fish in their natural habitat for trade. Human activities like introducing invasive fish and plant species also contribute to changing the wetland environment.For instance introducing rainbow trout fish to natural streams in Horton Plains, resulted in other fish species being virtually exterminated.   

Muthurajawela has an important peat land area that can absorb a huge quantity of water during heavy rains to be released as purified water in dry weather helping to keep a healthy ground water level, behaving like a natural sponge protecting the environment and the people. Peat lands are said to store 90% of water compared to their soil capacity. And those peat lands are twice as much richer in carbon than forests and if peat is burned by some kind of illegal activity, it adds to global warming by increasing the atmospheric carbon level. Constructing roads and buildings as well as illegal constructions and invasive species like “Wel Anona” are threats to this natural sponge called peat lands, reports say.   

Colombo and the suburbs get flooded during heavy rains causing havoc to hundreds of thousands of people as we saw last year. Muthurajawela for decades has helped in absorbing a great deal of flood waters securing the surrounding lands and settlements. There should be some kind of protection for still unprotected areas in Muthurajawela where land fillings have had a negative impact. We urge action by the government to safeguard and control the human activities there and other wetlands.