Valuing our Ecosystems: The Role of Wetlands

Have you ever found yourself admiring the calls of ducks, the croaking of frogs across a lake, or the swaying of reeds while walking your dog at your local wetlands? Have you wondered how wetlands are able retain to water for such long periods of time, or been awed by the myriad of wildlife you’ve encountered in their vicinity?

Wetlands are amazingly diverse habitats, home to thousands of different species worldwide. However, according to the most recent scientific studies, 64% of the world’s wetlands have disappeared since 1900 and 76% of freshwater plants and animals have disappeared in the last 40 years, making them among the most vulnerable of ecosystems.

The Murray River at Swan Reach in South Australia. The wetlands have dried up as the flow of the water has reduced. Image: Murray Darling Water Authority.

The Murray River at Swan Reach in South Australia. The wetlands have dried up as the flow of the water has reduced. Image: Murray Darling Water Authority.

One of the reasons for this is that wetlands are increasingly being targeted for land reclamation and conversion into agricultural, industrial and urban areas. Yet, they play a much bigger role in the ongoing prosperity of our communities, and this is something worth discussing. So, what value do our wetland habitats offer?

The Importance of Wetlands

Wetlands are areas of land that are saturated or flooded with water, either permanently or seasonally. There are many kinds of wetlands including both inland wetlands such as marshes, ponds, lakes, fens, rivers, floodplains and swamps, as well as coastal wetlands, such as saltwater marshes, estuaries, mangroves, and lagoons. The size of wetlands also varies dramatically, from less than a single hectare (around the size of your local lake) to the Pantanal in Brazil, Bolivia and Paraguay, which covers an area three times the size of Ireland.

Thousands of different species of birds visit wetland areas to breed. Image: CSIRO. 

Thousands of different species of birds visit wetland areas to breed. Image: CSIRO. 

Wetlands are home to more than 100, 000 known freshwater species and this number is growing all the time. Between 1999 and 2009, some 257 new species of freshwater fish were discovered in the Amazon alone. Wetlands in Australia also provide breeding grounds for up to 2 million migratory birds that travel thousands of kilometres for their annual breeding migration.     

The red-necked stint is a small migratory bird that nests in the Siberian tundra before traveling thousands of kilometres to reach Australian shores. After a six month break, it then makes the return journey back to Siberia to breed.  Image: Wikimedia Commons

The red-necked stint is a small migratory bird that nests in the Siberian tundra before traveling thousands of kilometres to reach Australian shores. After a six month break, it then makes the return journey back to Siberia to breed.  Image: Wikimedia Commons

A Crucial Role in Mitigating Climate Change

Aside from providing a habitat for wildlife, wetlands are also known to provide other ecosystem services such as reducing erosion and flooding, improving water quality, and, notably, playing a crucial role in mitigating the impacts of climate change. In particular, peatlands (areas with a thick, water-logged, organic soil layer) act as a key means of carbon storage. Globally, peatlands only cover an estimated 3% of the world’s land area, but hold up to 550 gigatonnes of CO2 - approximately 30% of all carbon stored on land. Amazingly, this is twice the amount of carbon stored in the world’s forests - not what you would expect, right? They therefore serve as vital areas to protect when tackling climate change.

Peatlands in Forsinard, United Kingdom. Image: RSPB.

Peatlands in Forsinard, United Kingdom. Image: RSPB.

In spite of this, warming temperatures as well as human development are threatening these habitats as they are burned, drained for agriculture, or exploited for oil and gas deposits. Consequently, they are being transformed from carbon sinks to carbon sources. According to Wetlands International, CO2 emissions from peatland fires equate to a staggering 5% of all annual fossil fuel. Furthermore, in Indonesia, emissions from peat soils due to logging and drainage contribute 60% to their total CO2 emissions (~900Mtons per year).

Finding a Balance

In a world that is undergoing both dramatic environmental and economic changes, decisions concerning the development of  native ecosystems are becoming increasingly difficult. In another article published by Wild Melbourne, the idea that half of the Earth must be ‘given’ to nature in order for it to continue to thrive is presented as a potential solution to the modern environmental crisis. When we consider all that wetland ecosystems do for us, their dramatic fall into degradation, and our rising global population, it is definitely a conversation worth having.

We know that just considering what the environment can provide for us in the short term is not a sustainable method of making these decisions. Perhaps, we need to ask ourselves what role the environment is already playing and whether we have placed sufficient value on those services. Only then can we begin to form a holistic and balanced approach to economic development that acknowledges the role of our wetlands and other ecosystems in both our present and future.  


Banner photo courtesy of CSIRO.