Human civilizations havegrown and thrived in river valleys and coastal plains with abundant wetlandsfor thousands of years. These wetland systems, with their rich naturalresources, have been critical to the development and survival of humanity andare part of our natural wealth.[1] Wetlandsexist in every country and in every climatic zone, from the polar regions tothe tropics, and from high altitudes to dry regions.[2] They are places where the land is covered by water, either salt,fresh or somewhere in between[3],including marshes and ponds, the edge of a lake or ocean, the delta at themouth of a river or low-lying areas that frequently flood. Wetland ecosystems include mangroves, peatlands andmarshes, rivers and lakes, deltas, floodplains and flooded forests,rice-fields, and even coral reefs[4].
The scientific community estimatesthat wetlands cover 6% of the world’s land surface withmangroves covering some 15.2 million hectares and coral reefs are estimated tocover 60 million hectares[5]. Further reach indicatesthat wetland ecosystems contain about 12% of theglobal carbon pool, playing an important role in the global carbon cycle.Important wetland functions include water storage, groundwater recharge, stormprotection, flood mitigation, shoreline stabilization, erosion control, andretention of carbon, nutrients, sediments and pollutants. Wetlands also producegoods that have a significant economic value such as clean water, fisheries,timber, peat, wildlife resources and tourism opportunities.
In Sri Lanka, wetlands have been a lifeline for bothhumans and animals for well over two thousand years. Sri Lankan ecosystemsinclude a variety of wetlands including inland natural freshwater wetlands,numerous lakes, marshes, streams, swamp forests and villus as well as marineand salt water wetlands such as lagoons, estuaries, mangroves, seagrass beds,and coral reefs and man-made wetlands. Bundala, Anaiwilundawa and Madugangawetlands are renowned worldwide for their unique biodiversity.[6]
Climate change isrecognized as a major threat to the survival of species and integrity ofecosystems worldwide. Scientific data predicts the ecological and hydrologicalimpacts expected to result from climate change have increased considerably overthe past decade.[7] Potentialclimate change impacts on wetlands are likely to be caused through changes inhydrology, direct and indirect effects of changing temperatures, and changingland use patterns.
Hydrologic impacts due toclimate change may range from sea level rise and salt water intrusion toincreased inundation on a seasonal or annual basis and loss of soil moisturedue to drying or drought. As wetlands move nutrients, pollutants and sediments from land towater[8], decreasing water flows dueto drought will cause these substances to accumulate in the wetlands andseriously endanger animal and plant life. As waterlevels decrease it would also increase the exposure of wetland sediment andincrease the concentration of salt in the soil. Indrier areas it will decrease the movement of water from regions ofhigher potential to regions of lower potential, overall restraining the ability of plant life to take up water fromthe soil. The concentration of othertoxics in the soil may also increase and causeproblems to both plants and animals due to theincreased rates of evapotranspiration[9].
As our planet becomeswarmer, in general, biological productivity increases with temperature.[10]Most aquatic birds in coastal areas depend upon seasonal flood pulses andgradual water reduction. Changes in the timing and severity of this flood pulsedue to climate change will affect the availability of safe breeding sites forbirds and amphibians, causing some wetland species to move away from their natural habitatsand paving the way for extinction[11].
Despite the impact of climatechange upon wetlands, recent reports have indicated that coastal wetlands areamong the best marine ecosystems to fight climate change.[12]Coastal wetlands take in carbon quickly and hold it for a long time. If theyare not protected, these ecosystems could release huge amounts of greenhousegases into the atmosphere, especially when temperatures rise, limiting thescope of some nations to meet their international climate commitments in theParis Agreement[13].
The ability of wetlands to buffer climate change impacts can beconsidered a natural adaptation measure. For example, mangroveforests provide protection and shelter from extreme weather events such asstorm winds and floods. Mangroves absorb and disperse tidal surges and canreduce the destructive force of a tsunami by up to 90%[14].They also play a major role in climate change mitigation, as coastal wetland vegetation such asmangroves stores so-called "blue carbon" and thereby acts as a carbonsink. It has been estimated that the world has lost around 3.6 millionhectares of mangroves since 1980, and that this has been a major reason for thedecline in coastal fisheries of many tropical and subtropical countries,including Sri Lanka.[15]
Protecting and Restoring Mangroves
Protecting and restoringmangrove habitats is vital in the fight against climate change and its impacts.New zones of mangrove habitat should be established where they do not clash with human development, sothey are capable of replenishing themselves landwards as the sea level rises [16].
To ensure that the wetlands areprotected, it is important that restoration practitioners take climate changeinto account when implementing restoration projects. Also, policymakers need toensure that wetland restoration is part of climate change adaptation andmitigation strategies for Sri Lanka. As wetlands help to maintain clean air,health, economy, human quality of life and the well-being of the naturalenvironment, restoring and protecting them is key to addressing climatechange and protecting the environment.[17]
[1] https://www.crestonwildlife.ca/wetlands/importance
[2] WETLAND,CLIMATE CHANGE, AND CARBON SEQUESTERING Prepared by: Jon Kusler Association ofState Wetland Managers, Inc
[3] https://www.wetlands.org
[4] Erwin,K.L. (2009) Wetlands and Global Climate Change: The Role of Wetland Restorationin a Changing World. Wetlands Ecology and Management, 17, 71-84
[5] http://www.espa.ac.uk/files/espa/P-Mowtick%20Mangrove%20report%20-%20KMFRI.pdf
[6]http://www.dailynews.lk/2018/02/28/features/144137/protecting-sri-lanka%E2%80%99s-wetland-ecosystems
[7] https://www.scientificamerican.com/article/wetlands-can-help-fight-climate-change/
[8] Impact of Climate Change on Wetland FunctionsDuck Gil Kim1 , Hui Seong Noh, Na Rae Kang, and Hung Soo Kim Department ofCivil Engineering, Inha University, Korea
[9] Focus on the impact of climate change on wetland ecosystems andcarbon dynamics, Lei Meng1, NigelRoulet, Qianlai Zhuang, Torben R Christensen and SteveFrolking Published 13 October2016 • ©2016IOPPublishingLtd Environmental ResearchLetters, Volume 11, Number 10
[10] https://www.zaragoza.es/contenidos/medioambiente/cajaAzul/10S3-P2-Perez%20LloresnACC.pdf
[11]Erwin, K.L.(2009) Wetlands and Global Climate Change: The Role of Wetland Restoration in aChanging World. Wetlands Ecology and Management, 17, 71-84
[12] https://www.zaragoza.es/contenidos/medioambiente/cajaAzul/10S3-P2-Perez%20LloresnACC.pdf
[13]Climate change impacts on freshwater wetlandhabitats, TerryP.DawsonaPam M.BerryaE.Kampaa,Journalfor Nature Conservation,Volume11, Issue 1, 2003, Pages 25-30
[14]http://www.wetlandpolicy.ca/wetlands-climate-change/
[15] Wetlands and Climate Change: Considerations forWetland Program Managers Association of State Wetland Managers
[16] Wetlands and Global Climate Change: The Role of WetlandRestoration In a Changing World Kevin L. Erwin Consulting Ecologist, Inc.Florida Gulf Coast University Department of Marine & Ecological Sciences2077 Bayside Parkway Ft. Myers, Florida 33901
Human civilizations havegrown and thrived in river valleys and coastal plains with abundant wetlandsfor thousands of years. These wetland systems, with their rich naturalresources, have been critical to the development and survival of humanity andare part of our natural wealth.[1] Wetlandsexist in every country and in every climatic zone, from the polar regions tothe tropics, and from high altitudes to dry regions.[2] They are places where the land is covered by water, either salt,fresh or somewhere in between[3],including marshes and ponds, the edge of a lake or ocean, the delta at themouth of a river or low-lying areas that frequently flood. Wetland ecosystems include mangroves, peatlands andmarshes, rivers and lakes, deltas, floodplains and flooded forests,rice-fields, and even coral reefs[4].
The scientific community estimatesthat wetlands cover 6% of the world’s land surface withmangroves covering some 15.2 million hectares and coral reefs are estimated tocover 60 million hectares[5]. Further reach indicatesthat wetland ecosystems contain about 12% of theglobal carbon pool, playing an important role in the global carbon cycle.Important wetland functions include water storage, groundwater recharge, stormprotection, flood mitigation, shoreline stabilization, erosion control, andretention of carbon, nutrients, sediments and pollutants. Wetlands also producegoods that have a significant economic value such as clean water, fisheries,timber, peat, wildlife resources and tourism opportunities.
In Sri Lanka, wetlands have been a lifeline for bothhumans and animals for well over two thousand years. Sri Lankan ecosystemsinclude a variety of wetlands including inland natural freshwater wetlands,numerous lakes, marshes, streams, swamp forests and villus as well as marineand salt water wetlands such as lagoons, estuaries, mangroves, seagrass beds,and coral reefs and man-made wetlands. Bundala, Anaiwilundawa and Madugangawetlands are renowned worldwide for their unique biodiversity.[6]
Climate change isrecognized as a major threat to the survival of species and integrity ofecosystems worldwide. Scientific data predicts the ecological and hydrologicalimpacts expected to result from climate change have increased considerably overthe past decade.[7] Potentialclimate change impacts on wetlands are likely to be caused through changes inhydrology, direct and indirect effects of changing temperatures, and changingland use patterns.
Hydrologic impacts due toclimate change may range from sea level rise and salt water intrusion toincreased inundation on a seasonal or annual basis and loss of soil moisturedue to drying or drought. As wetlands move nutrients, pollutants and sediments from land towater[8], decreasing water flows dueto drought will cause these substances to accumulate in the wetlands andseriously endanger animal and plant life. As waterlevels decrease it would also increase the exposure of wetland sediment andincrease the concentration of salt in the soil. Indrier areas it will decrease the movement of water from regions ofhigher potential to regions of lower potential, overall restraining the ability of plant life to take up water fromthe soil. The concentration of othertoxics in the soil may also increase and causeproblems to both plants and animals due to theincreased rates of evapotranspiration[9].
As our planet becomeswarmer, in general, biological productivity increases with temperature.[10]Most aquatic birds in coastal areas depend upon seasonal flood pulses andgradual water reduction. Changes in the timing and severity of this flood pulsedue to climate change will affect the availability of safe breeding sites forbirds and amphibians, causing some wetland species to move away from their natural habitatsand paving the way for extinction[11].
Despite the impact of climatechange upon wetlands, recent reports have indicated that coastal wetlands areamong the best marine ecosystems to fight climate change.[12]Coastal wetlands take in carbon quickly and hold it for a long time. If theyare not protected, these ecosystems could release huge amounts of greenhousegases into the atmosphere, especially when temperatures rise, limiting thescope of some nations to meet their international climate commitments in theParis Agreement[13].
The ability of wetlands to buffer climate change impacts can beconsidered a natural adaptation measure. For example, mangroveforests provide protection and shelter from extreme weather events such asstorm winds and floods. Mangroves absorb and disperse tidal surges and canreduce the destructive force of a tsunami by up to 90%[14].They also play a major role in climate change mitigation, as coastal wetland vegetation such asmangroves stores so-called "blue carbon" and thereby acts as a carbonsink. It has been estimated that the world has lost around 3.6 millionhectares of mangroves since 1980, and that this has been a major reason for thedecline in coastal fisheries of many tropical and subtropical countries,including Sri Lanka.[15]
Protecting and Restoring Mangroves
Protecting and restoringmangrove habitats is vital in the fight against climate change and its impacts.New zones of mangrove habitat should be established where they do not clash with human development, sothey are capable of replenishing themselves landwards as the sea level rises [16].
To ensure that the wetlands areprotected, it is important that restoration practitioners take climate changeinto account when implementing restoration projects. Also, policymakers need toensure that wetland restoration is part of climate change adaptation andmitigation strategies for Sri Lanka. As wetlands help to maintain clean air,health, economy, human quality of life and the well-being of the naturalenvironment, restoring and protecting them is key to addressing climatechange and protecting the environment.[17]
[1] https://www.crestonwildlife.ca/wetlands/importance
[2] WETLAND,CLIMATE CHANGE, AND CARBON SEQUESTERING Prepared by: Jon Kusler Association ofState Wetland Managers, Inc
[3] https://www.wetlands.org
[4] Erwin,K.L. (2009) Wetlands and Global Climate Change: The Role of Wetland Restorationin a Changing World. Wetlands Ecology and Management, 17, 71-84
[5] http://www.espa.ac.uk/files/espa/P-Mowtick%20Mangrove%20report%20-%20KMFRI.pdf
[6]http://www.dailynews.lk/2018/02/28/features/144137/protecting-sri-lanka%E2%80%99s-wetland-ecosystems
[7] https://www.scientificamerican.com/article/wetlands-can-help-fight-climate-change/
[8] Impact of Climate Change on Wetland FunctionsDuck Gil Kim1 , Hui Seong Noh, Na Rae Kang, and Hung Soo Kim Department ofCivil Engineering, Inha University, Korea
[9] Focus on the impact of climate change on wetland ecosystems andcarbon dynamics, Lei Meng1, NigelRoulet, Qianlai Zhuang, Torben R Christensen and SteveFrolking Published 13 October2016 • ©2016IOPPublishingLtd Environmental ResearchLetters, Volume 11, Number 10
[10] https://www.zaragoza.es/contenidos/medioambiente/cajaAzul/10S3-P2-Perez%20LloresnACC.pdf
[11]Erwin, K.L.(2009) Wetlands and Global Climate Change: The Role of Wetland Restoration in aChanging World. Wetlands Ecology and Management, 17, 71-84
[12] https://www.zaragoza.es/contenidos/medioambiente/cajaAzul/10S3-P2-Perez%20LloresnACC.pdf
[13]Climate change impacts on freshwater wetlandhabitats, TerryP.DawsonaPam M.BerryaE.Kampaa,Journalfor Nature Conservation,Volume11, Issue 1, 2003, Pages 25-30
[14]http://www.wetlandpolicy.ca/wetlands-climate-change/
[15] Wetlands and Climate Change: Considerations forWetland Program Managers Association of State Wetland Managers
[16] Wetlands and Global Climate Change: The Role of WetlandRestoration In a Changing World Kevin L. Erwin Consulting Ecologist, Inc.Florida Gulf Coast University Department of Marine & Ecological Sciences2077 Bayside Parkway Ft. Myers, Florida 33901
.png)