Our Wetlands In A Changing Climate

As ecosystems that thrive on so little, our wetlands are delicate. Yet they are abundant sources of water in this growingly water-starved world. They are carbon sinks, that remove and trap over 13% of the world’s carbon. They are biodiversity hot-spots where some of the most beautiful and unique species live and flourish.

While we are fortunate to still see wetlands around us, their survival is threatened. They are exhibiting what the scientists are calling a ‘distress syndrome’, wherein, their functional capacity has been radically impaired. Their plant and animal distributions have been drastically altered. And there are several disturbances, induced stresses and a range of pressures that are making their fragile ecosystems imbalanced.

Image of a starving polar bear on a melting ice sheet

Much of this has been the result of climate change. A topic that is heavily discussed but less understood in the context of wetland conservation and rehabilitation. It is only gradually becoming clear that climate change impacts each wetland in a specific and unpredictable way. And it is through constant monitoring, research, on-ground work and active participation that some of the impacts can be stalled or even reversed.

Our conservation efforts at Bibra Lake and North Lake, within the Beeliar Regional Park, have been remarkable. Through the course of our work, we are constantly learning about the nature of our wetlands, their many unseen facets and how they respond to a steadily shifting environment.

In this article, we draw a sketch of the strengths and weaknesses of our dynamic Beeliar Wetlands as they stand the test of a changing climate. And what it will take for them to survive this massive global event.

Understanding climate change

Climate change is perhaps the greatest issue confronting us today!  As greenhouse emissions continue to rise it is predicted that global temperatures could increase anywhere between 1-5 degrees in the 21st century.


This video from NASA’s Climate Change website, highlights global temperature anomalies. 2018 and 2017 were the fourth and second hottest years respectively since modern record-keeping began in 1880. NASA and NOAA work together to track the temperatures, part of ongoing research into our warming planet.

Major atmospheric changes drive hydrological changes. So, global warming at that scale can lead to prolonged droughts in some areas and pronounced precipitation in others. Hydrological changes further drive hydrogeological changes affecting groundwater recharge and water purity. These changes themselves are enough to degrade some wetlands considerably.

The continuing rise in temperatures also threatens species who depend on the wetlands for survival. Waterfowl are susceptible to changes in temperature and precipitation. For migratory birds, the climate affects their habitats as well as the migration corridors. For other species whose breeding cycles are tied closely to the climatic conditions, the rise in temperatures makes the situation unfavourable.

Climate change has a range of other impacts on the wetlands themselves, their ability to recycle and process nutrients, how they absorb and trap carbon and process sediments to generate soil. These activities further impact the distribution of flora and fauna, favouring some over the other. Invasive species thrive and change wetland ecology, damaging habitat and food source.

The stresses of climate change are only heightened by human activity – urbanization and pollution.

Climate change and Beeliar Wetlands

The Beeliar Wetlands is the name given to the two chains of wetlands that run parallel to the west coast of Western Australia. While one chain of lakes is saline, the other is freshwater. The wetlands are located towards the southwest portion of metropolitan Perth within the larger Beeliar Regional Park.

The wetlands on the Swan Coastal Plain and in particular the Beeliar Wetlands are a surface expression of the underlying groundwater.  There is still much to be learnt about the effects of climate change on our wetlands.  What the data shows us is that for about the last 40 years we have been receiving less rain.

Groundwater levels have never been static, decreasing during summer and increasing when recharged with winter rain as water makes its way through the soil to groundwater.  With decreasing rainfall, the groundwater recharge has decreased and levels have dropped. Together with the decreasing recharge, there has also been incessant removal of groundwater to supplement our supply of drinking water.

In most cases, this has led to our wetlands drying out more often or for prolonged periods each year. But, bear in mind, a drying wetland is natural and it is during the drying times that those intrepid birds fly in from Siberia to eat the bugs out of our mud.  It’s tricky business and honestly, none of us have the whole story.

The unpredictable changes in the lakes drying and filling have also complicated our revegetation efforts.  While in general we are allowing for increased dry conditions and adjusting the zones in which we plant, on several occasions we have been caught with heavy summer and spring rain events inundating some of our plantings.  These conditions highlight the need for Adaptive Management.

It is not only the wetland and wetland vegetation that is affected by this lowering of the water table.  Many of our bushland species also depend on groundwater for survival.  This became very evident during the particularly low rainfall season of 2010-11 when many banksias higher in the landscape of our bushland died.

Changes in global climate may well be a contributing factor on groundwater levels, but healthy well-maintained wetlands can also be a key tool in our efforts to lessen the impact of climate change on other systems.

Here’s taking a closer look at the Beeliar Wetlands and how climate change has impacted some of the wetland functions.

1. Changing Hydrology:

The Beeliar Wetlands depend on seasonal rain to recharge. Over the years there have been fluctuations in the amount of precipitation. These fluctuations have caused alterations in wetland zonation, impacting the distribution of native plant species within the wetlands.

2. Loss of biodiversity:

With changing zonation, wading species and waterfowl are impacted.  Constant encroachment has led to a serious habitat loss, loss of fringing vegetation and bushland. This has further impacted species such as turtles, frogs, snakes and lizards many of which are endangered.

3. Carbon loss:

With many of the wetlands now experiencing a dry spell and terrestrialisation, the carbon trapped within the soils is released back into the atmosphere. And there is a further loss in capacity to capture and trap carbon from the atmosphere due to the growing number of dysfunctional and degraded wetlands.

Read our blog post on ‘Saving Bibra Lake’ for an in-depth examination into our conservation and rehabilitation efforts on Bibra Lake and North Lake.

Preventative measures

The wetlands are facing an incredible amount of stress from climate change alone, and we have to realize the importance of reducing additional pressures. This will give our wetlands a fighting chance to cope and replenish.

While most of us have come to accept the reality of human-caused changes in our global climate, we must also step up to the task of addressing the impacts of these changes.  There are many actions we can take locally to help our wetlands through this period.

Here are a few ways in which we as individuals and community can help:

  1. Reduce waste. Don’t litter.
  2. Conserve water. Be judicious. Click this link to check out Watercorp’s tips for saving water.
  3. Recycle and reuse to the maximum extent.
  4. Reduce your carbon footprint.
  5. Walk or cycle wherever you can. Or use public transport.
  6. Grow native plants in your garden. Go organic. Be fertilisewise!
  7. Participate in wetland activities. Volunteer with The Wetlands Centre.

Don’t forget to quack, quack, quack…  That is wetland speak for talk, talk, talk…  Pass on the message to friends and family.  Tell them about waterwise, fertilisewise and of course, volunteering.

Join The Wetlands Centre Cockburn

At ‘The Wetlands Centre Cockburn’, we are located a hop, skip and jump away from the glorious Bibra Lake, within the Beeliar Regional Park. Our proximity stirs and inspires us to work with the community to safeguard and protect this amazing yet fragile asset.

Community Planting Event at Horse Paddock Swamp in the Beeliar Wetlands

We have seen remarkable progress over the 25 years we have been around and are always looking for new helpers.  If you are not into getting down and dirty, we have education programs that need helpers too!

Combating climate change will take all our effort. Come join our forces today. Together let us maintain and improve the resilience of our wetlands so that they can continue to provide important services to us and the coming generations, even under changed climatic conditions.

7 Things You Should Know About Our Wetlands

A beautiful scene of wetlands at sunset

Our stunning wetlands are a remarkable feature of the Australian landscape. From rivers that crisscross our cities and drain into surrounding seas, to the vast floodplains of central Australia that only see water every few years, these breathtaking natural and artificial wetlands capture our imagination.

The amazing diversity of lakes, mudflats and billabongs, marshes, swamps and fens and coral reefs, mangroves and peatlands – our wetlands come in all shapes and sizes. Even amidst our urban sprawl, we have manmade lakes, ponds and canals, together with some serene natural wetlands that serve as centres of recreation for us and refuge for our wildlife.

We often pass by them wondering at their natural beauty and abundance. The diverse wildlife and plant-life they support. Their scenic beauty. The interlinkages and connections. And the cycles and seasons that bring out their unique character. Yet their many other (important) functions go largely unnoticed by us.

It is hard to imagine Australia without its beautiful wetlands. They are special places serving as storehouses of life-giving water. And, they play a key role beyond sustenance, water conservation and climate control.

 

1. Wetlands are “Nature’s Kidneys”

Wetlands have been likened to nature’s kidneys owing to their deep cleansing effect on our waterways. They are essential for sustaining healthy waterways on which communities throughout Australia depend.

Much like the kidneys that filter and extract waste and balance the hormones in the human body, the wetlands trap and filter the nutrients, sediments and pollutants, cleaning the water and recharging the underground aquifers. By absorbing pollutants, wetlands improve the quality of water and the surrounding bushland.

 

2. Wetlands and the Impact on Climate Change

Wetlands have the unique ability to capture and store carbon dioxide from the atmosphere, thus slowing the impacts of climate change. Coastal wetlands are known to store large quantities of ‘blue carbon’ (the carbon in coastal ecosystems is known as blue carbon).

The flourishing vegetation is responsible for consuming carbon dioxide. Some of the used-up carbon dioxide is released back into the atmosphere, but most of it remains trapped around the roots, sediments and in the marshy ground.

Statistics show us that although the wetlands cover only 5 – 8% of the Earth’s land surface, they hold anywhere up to 30% of the total store of carbon on the planet.

 

3. Wetlands Act as Storm Buffers

Wetlands perform a crucial function as storm buffers – including inland flood control and coastal storm buffers. The thriving foliage – seagrasses, reefs, rushes, reeds, bushes and more – all protect against the destructive action of flood-water and dampen their impact.

Wetlands protect coastal communities from extreme events, such as typhoons, cyclones and hurricanes. They protect our shores from corrosive wave action.

 

4. Wetlands Serve as Habitats for Biodiversity

Wetlands are vital habitats for native species such as the oblong turtles and black swans, as well as a horde of international migratory birds such as greenshanks, red-necked stints and sharp-tailed sandpipers. They provide much-needed refuge for a number of migratory shorebird and seabird species, serving as important feeding and resting habitats during spring and summer months. Some endangered species such as Carnaby’s cockatoo and the peregrine falcon rely on the wetlands for their food and water.

Wetlands support a unique ecosystem. And some of the plant and animal varieties are curiously distinct, having evolved specifically to survive the changing water and salinity conditions.

 

5. Artificial Wetlands and Recreation

Constructed wetlands or manmade wetlands, that are designed to mimic our natural wetlands are often found in urban areas. They can serve the same function as our natural wetlands – of supporting wildlife and creating booming ecosystems and habitats, although they often lack the amazing biodiversity of natural wetlands.

Artificial wetlands are popular destinations for recreation and ecotourism, they also provide us with an opportunity of ‘experiencing nature’ right in the heart of our own cities and suburbs.

 

6. Water Conservation and Sustenance

The wetlands ecosystem teaches us a great deal about water and water conservation. The underground aquifers, which are vast, natural, water-storage reservoirs in the wetlands ecosystem, help replenish the groundwater. While the wetlands themselves act as filters, cleaning and restoring our waterways. The wetlands are often the surface expressions of these aquifers.

All Australians rely on water to sustain life. And water plays a large part in our lives. Whether it’s water for our households, schools, industries or communities, wetlands play an indispensable role and their conservation should be a top priority.

 

7. Wetlands Need Our Support

Threats to wetlands continue as many of them are being filled, drained and replaced with agricultural fields, roadways and urban developments. Rural and urban encroachment is perhaps the biggest threat. Leaving our animal and bird populations homeless, our waterways exposed and compromised, and our environment permanently degraded.

The wetlands need our support today. From generating public awareness to community involvement in their protection and rehabilitation.

We encourage you to visit us – The Wetlands Centre at Bibra Lake – or your nearest wetlands, to learn about our community outreach and how local communities can participate in and benefit from the wetlands.