The Value Of Mangroves: Ecological Services Of Mangroves In Sri Lanka

By Buddhika Ranadheera –AUGUST 3, 2018

Buddhika Ranadheera

Mangroves are a valuable ecological and economic resource to Sri Lanka. According to the Forest Department, Sri Lanka is home to over 20 mangrove species which extend over an area of 15,670 hectares. However, mangroves represent only 0.2% of the total forest cover. 

Mangroves and the Economy

The coastal, inland, and offshore fisheries contributed 1.3% of the GDP of Sri Lanka in 2017. However, there has been a decline in coastal fishery production by 5.3% while inland aquaculture, shrimp, and prawn production declined by 7.9 % and 23.4 % compared to 2016. Mangrove depletion is considered as being among the reasons for this depletion, indicating that the survival and healthy growth of mangroves is a crucial component to the sustainability of the fishing industry.

Mangroves in Sri Lanka provide wood and timber for housing, firewood, and charcoal to coastal households. Almost 75% of the coastal population extracts firewood from mangrove forests. The coastal community also depends on mangroves for bottle caps and ornamental production. 

Ecological Services 

Mangroves are pivotal coastal ecosystems and play a key role in weathering climate change impacts such as storms, hurricanes, and tsunamis while mitigating its causes. The value of mangroves in carbon sequestration is higher than terrestrial forests. Mangrove forests absorb up to four times more carbon per hectare than other tropical forests. This unique ecosystem also provides a nursery habitat for many wildlife species, including commercial fish and crustaceans, and contributes to sustaining the local abundance of fish and shellfish populations. Mangroves also provide shelter and feeding grounds for many reptiles and nesting grounds for local and migratory birds.  

Further, mangroves facilitate the growth of corals and provide shelter for coral species at risk of extinction from coral bleaching. Coral bleaching is one of the calamitous effects of climate change, and it is worsened by the absorption of more carbon by the oceans. Several species such as seagrass beds cannot survive without mangroves, and it is vital to ensure that mangroves are protected as they can withstand sea level rise and help mitigate coastal erosion. 

Climate Change Impacts on Mangroves 

A large percentage of mangrove populations in Sri Lanka have been subjected to depletion and deforestation as a result of anthropogenic activities as well as natural disasters. They have been threatened by natural disasters while functioning as a buffer and protecting the coast. During the 2004 Tsunami, most of the mangroves along the Southern belt were destroyed. With the intensity of climate change and natural perils rising, more and more mangroves are destroyed and the time needed for recovery gets extended. 

The Human Threat

Human settlements in the coastal areas threaten mangroves. With one third of the population in Sri Lanka living along the coastal belt, and human settlements in the coastal areas of Sri Lanka ever expanding, the waste disposals of these human settlements cause a significant threat to coastal ecosystems such as mangroves. Even though mangroves are resilient to disturbances, the pollutants cause considerable damage to them. 

Mangroves are highly threatened by the unprecedented and unhealthy growth of the tourism sector. They are being deforested to build tourist resorts and infrastructure as well as to have a better view of the ocean. The roots, fruits, and flowers of particular species of mangroves are also being used to create ornaments and lids at unsustainable levels. 

There has been indiscriminate exploitation of mangroves for commercial purposes including deforestation of mangroves to build salt beds, aquaculture ponds, and prawn farms. With increasing consumer demand for shrimps and the expansion of export-oriented prawn farming, more mangrove forests have been lost. 

The civil war has also contributed to the destruction of mangroves in the North and the North East of Sri Lanka, which is further impacting the economy of the communities dependent on the ecosystem for their livelihood. 

Read More