Discover our waterway warriors

In Melbourne’s bustling inner CBD, sometimes it’s hard to comprehend the diversity of the nature around us - we can often feel disconnected. There are many hidden opportunities for us to engage with our rich flora, fauna and green spaces at a local scale and reconnect with the natural world.

Green spaces, wetlands and the biodiversity within them contribute to the livability of Melbourne as well as play a vital role in maintaining people’s health and wellbeing – healthy environments, healthy people. Melbourne is home to many wetland environments, from extensive natural waterways such as the Tarago River in Werribee and the Yarra River, to the constructed wetlands of Trin Warren Tam-boore in Royal Park.

Australia’s first nationwide waterway monitoring event, the National Waterbug Blitz, is the perfect opportunity to engage with Victoria’s unique freshwater ecology and learn about the health of our waterways.

 Trin Warren Tam-boore Wetland in Royal Park.  Image:    City of Melbourne

Trin Warren Tam-boore Wetland in Royal Park. Image: City of Melbourne

Wetlands are biodiversity hotspots which provide community spaces and habitat for wildlife, filter stormwater, reduce riverbank erosion, and support many other functions essential to urban and rural life.

Every puddle and river you step past or in contains miniature worlds with intricate networks of food webs and species with multi-stage lifecycles. Pick up any stone or submerged piece of wood from your nearest waterway, turn it over and you will reveal a variety of scattering creatures under a thin film of water – these are freshwater macroinvertebrates, more commonly known as waterbugs.

Waterbugs are a diverse group of critters that lack a backbone (they’re invertebrates!). They are large enough for humans to see with the naked eye, and include leeches, worms, jellyfish, dragonfly larva, water boatmen and even freshwater sponges, each with their own unique way of life. Waterbugs perform various functions within waterway ecosystems, including sediment mixing, nutrient cycling, energy flow through food webs and the breakdown of organic matter, which releases nutrients into the water - some species contributing more than others. These actions all contribute to and determine the condition of the waterway system.

Macroinvertebrates can live in all kinds of freshwater environments, but which species are present in a particular wetland is highly dependent on the water quality, each individual species differing in its pollutant sensitivity. This means that waterbugs can be used all around the world as direct bioindicators for environmental health and pollutant impact within our waterways.

 Water Boatman Nymph.  Image: Larah McElro /    Flickr    [CC BY-NC 2.0 (https://creativecommons.org/licenses/by-nc/2.0/legalcode)].

Water Boatman Nymph. Image: Larah McElro / Flickr [CC BY-NC 2.0 (https://creativecommons.org/licenses/by-nc/2.0/legalcode)].

In healthy ecosystems, there will be as many as if not more pollutant-sensitive macroinvertebrates than those more tolerant of bad conditions. The release of pollutants creates an unstable environment that disrupts the species balance in an ecosystem, allowing tolerant species to thrive whilst essential, sensitive species suffer and decline in number.

As well as being easy to sample using simple tools, anybody can observe this diverse array of creatures. Waterbugs are abundant within all aquatic ecosystems; every river, lake and wetland is home to a plethora of different types. They have relatively short lifespans and thus show the effects of environmental conditions over a short period of time – weeks to months. Any change in the waterbug community will be indicative of recent changes to environmental quality, giving a robust picture of the ecosystem’s current state.

That’s not to say there aren’t difficulties when monitoring waterbugs. Although there is a menagerie of diverse species, there are many species that are yet to be properly described. It can also be difficult for the average environmentalist to identify waterbugs to a species level without formal training.

 A gradient of the pollution sensitivity or tolerance levels of various waterbugs.  Image:    National Waterbug Blitz

A gradient of the pollution sensitivity or tolerance levels of various waterbugs. Image: National Waterbug Blitz

Considering each waterbug warrior has a job to perform, with declining numbers we may begin to lose their functions within ecosystems. Digging deeper, each of these species arguably has an intrinsic value, no matter how small they might be.

With more research being done every day into our wonderful waterbugs, we can hopefully begin to better understand their relevance in the larger, complex ecosystems that they inhabit. The good news is that anyone can get involved in the City of Melbourne’s free Melbourne Waterbug Blitz events this October. Make sure you come along to one or more of the following events if you’d like to contribute to our understanding of Melbourne’s incredible waterbugs. It’s a great way to connect to nature in the middle of the city.

Science Seminar – Wednesday 10th October, 5:30pm-8:00pm at the Hellenic Museum (280 William St)

This will cover the importance of waterbugs, freshwater ecosystems and waterway health in urban areas. Speeches from waterbug experts, freshwater ecologists and urban ecologists.

Waterbug Collection – Saturday 20th October, 10:00am-11:30am at various locations

Join expert survey leaders in Melbourne’s beautiful parks and help collect samples of the living waterbugs in our waterways. Choose from Carlton Gardens, Domain Parklands, Fitzroy Gardens or Royal Park.

Dragonfly Festival – Saturday 20th October, 12:30pm-4:00pm at the State Netball and Hockey Centre, Royal Park

Get to know the local waterbugs a little better – take a closer look at the samples gathered from the morning sessions and uncover the secrets about Melbourne’s waterways. There will be food, refreshments, activities and family fun.

You can also download The Waterbug App and conduct a survey yourself.

The Waterbug Blitz is a great opportunity to get involved and put waterways under the magnifying glass by collecting valuable data and assessing the wellbeing of our freshwater ecosystems. This will help both the environment and our management of it, but it’s also a great way to engage with nature and have some fun with your local community.

So grab a net, a magnifying glass and a small container and let’s get surveying!

For more information about the National Waterbug Blitz and associated events head to www.waterbugblitz.org.au.


Johanna Tachas is a third year undergraduate student at the University of Melbourne studying ecology and evolutionary biology. She has a passion for science communication and is currently completing an internship at Remember The Wild.


Banner image of a Blue Skimmer (Orthetrum caledonicum) courtesy of Richard Higgins from Wollongong, Australia (Flickr) [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons.