Saving Bibra Lake

An aerial view of Bibra Lake on a sunny day

Cradled in the swales of the ancient dunes of the Swan Coastal Plain, and spanning over 384 hectares are the Beeliar Wetlands! They are bustling with stunning biodiversity, that include some of the most unique and fragile lifeforms on earth. Here, the calm, placid Bibra Lake stands as a timeless testament to our heritage and cultural values.

Historically, North Lake – Coolbellup and Bibra Lake – Walliabup, have served as important locations for the Aboriginal Nyoongar people. They are associated with the mythology of the ‘Waugal‘– the rainbow serpent, and Dreamtime tales of the ‘Spirit Children’.  Numerous Aboriginal campsites have been documented adjacent to the lakes. The Beeliar mob had semi-permanent camps on the land, caring for the boodja (country), precisely where the controversial Roe 8 tollway was proposed.

While we closely evaded that disaster, there are still a number of factors that continue to impact our precious wetlands. Over 90% of Perth’s once ample and abundant wetlands have been lost to agricultural pursuits, urbanisation, and development & infill. Bibra Lake and the surrounds are a reminder of what we’ve lost and what we stand to lose unless we take strong action. Together.

 

Changing wetlands in a changing climate

Our wetlands are dynamic in nature and they transform with changing seasons. Water levels in the wetlands, such as Bibra Lake, rise and fall with rainfall and the seasonal movement of groundwater. Bibra Lake experiences this seasonal flooding and drying, and oftentimes, this leads to alterations in the depth and area of the body of the lake. The transient wetlands are designed to cope, redistributing their animal and plant life in accordance with these changes.

However, with a decrease in rainfall and an increase in human activity surrounding our wetlands, the natural variations are becoming exaggerated. Causing alarming fluctuations in the wetland zonation. Introducing irreversible expansions and contractions of the wetland area.

 

Comparisson of flooded zones of Bibra Lake from 1995 to 2005
Figures depicting altered wetland zonation for Bibra Lake

Looking back, we remember the water levels of Bibra Lake during the 1980’s and 1990’s to be much higher than they are now. Many of us believe that those water levels were “proper”. However, the higher water levels of Bibra Lake at the time were actually an aberration caused by the removal of vegetative cover for the development of surrounding suburbs.

On the other hand, we also see prolonged drying of the wetlands in some years. The reduced rainfall has impacted the recharging of groundwater. And since the groundwater is also our source of drinking water for the Perth metropolitan area, this has caused a further shrinkage of the precious resource.

Bibra Lake has suffered adverse impacts. Usually, maximum water levels were seen around October and minimum levels during April. However, Bibra Lake and North Lake are now breaching these standards. This has significant implications for planting and weed control.

 

Two pictures comparing seasonal water levels of Bibra Lake
Snapshots comparing maximum and minimum seasonal water levels in Bibra Lake

A thorough understanding of these circumstances is essential towards developing a successful restoration program for Bibra Lake. We need to take the variations and on-ground conditions into account, adjusting when and where we weed and plant as we maintain and restore the lake and its surrounds.  The focus as we move forward must be on adaptive management.

We must also accept that we are moving into a period of some uncertainty, with climate change and global/local weather events becoming unpredictable. We may not get this 100% right 100% of the time. But every failure is a learning and a step forward.

 

Weeds and invasive species

Weeds are one of the most pressing problems we face at Bibra Lake, and weed control is an ongoing initiative. Often, the removal of one weed creates space for another. In some cases, it even allows the overgrowth of opportunistic native plants which can pose additional challenges. We see this most starkly in the constant balancing act of Typha control on our lakes. But that is a story for another day…

A combination of manual and chemical control along with mulching and saturation planting has been the most effective method in combating weeds. (Saturation planting is when native vegetation is planted densely and in large numbers so as to saturate and give little scope for invasive species to spread.)

At Bibra Lake, the following have been our findings:

  • Weeds must be actively growing before initiating weed control.
  • The revegetation plan should be in place prior to weed management to make the best use of the weed control efforts.
  • A monthly weed control commitment is required with a plan for the whole year.
  • At The Wetlands Centre, we have developed Seed Production Areas (SPAs) and refined propagation techniques to grow plants in our nursery.
  • The weed biomass in the seasonal zone degrades during one flooding and receding event. Slashing is sometimes required to make the area suitable for planting.
  • Mulching of the lower damp to upper seasonal zone (the weediest zone) with Typha mulch reduced the frequency of weed control.

 

Satelite images of Bibra Lake from 1953 to 2018 showing vegetation cover
Satellite images showing revegetation of Bibra Lake by The Wetlands Centre Cockburn over the years

Invasive species such as feral bees, foxes and cats are also detrimental to our wetlands. The feral cats and foxes prey on vulnerable native animals. Foxes are an introduced species and our lizards, turtles and quenda are especially susceptible since they have not developed any specific defences to stay protected.

 

Runoff and Algal Blooms

Human activity is primarily responsible for the degradation of our wetlands. Our urban developments are placed closer and closer to the wetlands, with little or no buffer. Roads and tracks crisscross the perimeter. And our wetlands are losing their lush cover, that helps protect wildlife from noise, light and other forms of pollution. All this further challenges their survival, exposing our species to danger and disease, and putting them at a risk of endangerment.

This also means that there is a greater impact on how nutrients, sediments and pollutants are naturally filtered by the wetland. The degraded quality of some of the fringing and upland vegetation around Bibra Lake is causing alterations in the water-quality of the catchment. However, Bibra Lake still fairs better than other heavily impacted lakes within the Beeliar Wetlands.

Runoff, whether it is the chemical runoff from roads or the phosphorus, potassium and nitrogen from fertilizers that we use in our gardens, leads to a nutrient explosion, and subsequently, algal blooms. The algae reduce temperature and light penetration in the catchments, suffocating and dominating over aquatic life. The algae also spread rapidly and give off an unpleasant odour as they break down. There is a direct link between the excessive use of garden and horticulture fertilizers and algal blooms in our waterways.

Reducing the use of chemicals in our gardens, keeping our storm drains clear of unwanted litter, conserving water and using it judiciously, and using landscaping practices that benefit wildlife and their habitats – every little step you take can lead to positive outcomes for our lake.

 

Join The Wetlands Centre Cockburn

At ‘The Wetlands Centre Cockburn’, we are fortunate to be located adjacent to the resplendent Bibra Lake, within the Beeliar Regional Park. This places us in an ideal position to lead by example in the care of our natural surroundings. We recognize that we bear a great responsibility to inspire, reinforce and connect, and to work with the community to safeguard and protect this amazing area.

The issues we have highlighted in this article are very real. They are threatening the health of our wonderful lake and its bountiful surrounds. We are working hard to understand and combat these issues while spreading awareness of core problems. Our team of volunteers and staff are dedicated and ever-vigilant.

In working with the land and connecting with its nurturing ways, we have come to cherish it deeply. And we want to share this connection with the greater community. Come, get involved with us. Learn. Plant. Protect. Conserve. And spread the joy.

 

This article is adapted from and based on notes and insights shared by Denise Crosbie, Wetlands Officer, The Wetlands Centre Cockburn.

5 Fun Ways You Can Help Your Wetlands With Citizen Science

People in a wetland catchment involved in a citizen science project

Nothing compares to the joy of giving! It is immense. And it is this shared joy and community spirit that are helping us rehabilitate and conserve our vulnerable wetlands.

For, rehabilitating the wetlands is a complex project with many moving parts. Its success relies on the contribution of our volunteers, tireless efforts of wetland staff and vigilance and attention of the active community. We are also fortunate to have many landcare owners and special interest groups that look out for and assist with wetland activity. These people are our heroes!

If you’ve felt like getting involved and contributing, our “Citizen Science” projects are a great place to start. You can work independently on your own initiative, with clear guidance and help from us anytime you need. The activities are interesting and you can see the final build up as collaborators from across the community come forth with their contributions. And finally, the results are made available and published for everyone to see. It is a truly enriching experience.

Here are 5 exciting projects that are currently happening. If you are keen about making a difference and getting involved, we’ve got all the information you need. So, let’s get started!

 

1.    Wildlife Sighting

What is involved: Record your lucky wildlife sightings. This activity involves keeping a lookout for wildlife and their movement through the wetlands and bush.

Our freshwater turtles are predominantly shy creatures that only venture outside their wetland sanctuary during special periods. They are on the move now (from September until January), searching for nesting sites to lay eggs. And soon in June, hatchlings will emerge to make their way back to the wetlands.  Our bobtails, quendas and myriad other endangered and/or sensitive wetland creatures too follow a similar pattern.

What you can do:

  1. Visit ClimateWatch.org.au/mobile and download the app that lets you record your wildlife sightings.
  2. Whenever you encounter a wild animal, take the time to record your wildlife sighting on the app. Ensure that you maintain a safe distance at all times.
  3. Visit or call your local wetlands centre for more information.

 

2.    Installing Frog Ponds

What is involved: Creating a natural setting pond ecosystem within your gardens and/or backyards especially catering to the native frog species. This activity involves setting up a beautiful pond at a suitable place at home that attracts the frogs.

Frog pond in a home garden

Frogs are incredible creatures with well-camouflaged dappled and textured skins, that gleam green, black or brown. And sometimes with vivid patterns to ward off predators. These fragile creatures are seriously endangered and their numbers are dwindling. By installing a frog pond, we are encouraging a growth in their numbers, and in turn, helping our wetland biodiversity.

What you can do:

  1. Download this document from South Australian EPA with information about this activity and how to install a frog pond. Also, refer to SERCUL’s Gardens for Frogs in Perth Brochure that provides information about frogs and frog ponds specific to Perth.
  2. Monitor and maintain the frog pond regularly.
  3. Visit FrogID.net.au to get the FrogID app. Install and use the app to monitor and report frog calls in your pond and around your locality.
  4. Visit or call your local wetlands centre for more information.

 

3.    Nest box Monitoring

What is involved: Install and monitor nest boxes for bats and other wildlife. This activity involves the installation and monitoring of nest boxes.

Nest boxes with easy Do-It-Yourself instructions are available to be installed at home or in parks around your home. Ensure that you take permission from your local council before proceeding. There is a high risk of feral bees invading and occupying nest boxes. So, ensure that you check for and report feral bee infestation immediately. Check for damage and weathering of boxes regularly. Also, check for animal health whenever, and to the extent possible, without disturbing the inhabiting species.

What you can do:

  1. Purchase and install the nestbox in an appropriate area. Get permission from your local council before commencing.
  2. Ensure you do it right by purchasing nest boxes that are expertly designed to inhibit infestation by feral bees, which can be very dangerous.
  3. Monitor for wildlife – bats, phascogales or possums. It is recommended that you check at least twice a year during January/February and June.
  4. For information about bat boxes, visit GoBatty.com.au and get in touch with local bat expert, Joe Tonga, who has extensive experience building and installing bat boxes.
  5. Visit or call your local wetlands centre for more information.

 

4.    Water Monitoring

What is involved: Monitoring the waterbodies – sea or freshwater. This activity involves uploading images of a water source to an app and regularly monitoring it for changes.

‘Eye on Water’, as the project is called, enables people to upload photographs of a target water source to an app. CSIRO has launched an app specifically for this purpose. The app then allows you to match the image using a colour chart and visually determine the quality of water.

The images are subsequently added to a global database that will support scientists in monitoring Australian waters for activity such as algal blooms, nutrient explosion, sediment and salinity levels and seasonal changes.

What you can do:

  1. Download and install the free CSIRO ‘Eye on Water’ app on your mobile phone.
  2. Choose a water body to monitor. While you are free to choose any type of water body, we encourage you to choose a wetland. Record your findings using the app.
  3. Visit or call your local wetlands centre for more information.

 

5.    Shorebird Monitoring

What is involved: Participating in this program involves going bird watching to collect information about shorebird movements and habitats. Help strengthen the case for shorebird protection.

Father and son bird watching around the wetlands

This shorebird program aims to raise awareness about the incredible birds, their habitats and movements. Continued monitoring of shorebird populations is essential to implement best practices.

What you can do:

  1. Go amateur birdwatching. There is no need for professional equipment or gear.
  2. Record the location of the birds. For birds around the wetlands, you can submit your sighting information using collection forms at our centre. Also, you can record any of your bird sightings using the Birdata app from this link.
  3. Visit or call your local wetlands centre for more information.

 

Come, get #WildAboutWetlands

There is a plethora of other activities, and if you are interested, we encourage you to visit your local wetlands centre and get involved today!

Kids wading into the wetlands to collect feathers for a citizen science project
Kids collecting feathers for the Australian ‘Bird Map’ Citizen Science Project at the Beeliar Wetlands

There are several ongoing projects at any given time and you may find something that piques your interest. For example, the Australia-wide Citizen Science project – “Feather Map of Australia” which completed in August 2018, involved wearing protective/waterproof gear and wading into wetland catchments to retrieve bird feathers and studying them. Another annual initiative – “Wild Pollinator Count” is about to begin and involves tracking and monitoring bees and insect pollinators and helping wildlife enthusiasts research and help in their conservation.

When you decide to participate, don’t forget to send us a picture of your project. We’ll be waiting!