The Friends of Merri Creek WaterWatch Team

This team of volunteers meets monthly on Merri Creek, just beneath the St Georges Road bridge. The group takes a range of readings to feed into records tracking movements in water quality. Data from this site has been recorded since 2003. The WaterWatch project and volunteers are supported by Julia Cirillo, Coordinator, Citizen Science and Waterway Education, with the Merri Creek Management Committee. 
 

The Team: Denise, Kirsten, Trevor, Khao and Nicole, photo by Jane Miller

There are 40 sites along the length of the Merri and tributaries, where water quality is monitored. The data from these surveys is fed into the WaterWatch Data Portal.

Our volunteers make a wonderful contribution to this program.
Kirsten writes:
I joined up to feel more connected to the waterways in my neighbourhood, which I felt like was a part of nature that I took for granted. I was amazed to find out how much life there is in the creek despite the quality of the water. I love seeing who's at home each month. The critters are just as tenacious as the volunteers who've been caring for it for so many years!

Nicole, also a Friends committee member, joined the WaterWatch Team for several reasons: 
I joined the Waterwatch team for a different activity to weeding and planting with the Friends. I am learning some technical and the common names of species in the creek as well as becoming aware of invasive critters. A side benefit is talking with people passing about the Friends and giving visitors a turn to catch macroinvertebrates.

Water samples are gathered and assessed for pH, salinity and turbidity: general indicators of water quality. Turbidity measurements – levels of suspended solid matter – are particularly important, as it increases enormously after heavy rain, due to stormwater runoff.

The water is also tested for

• dissolved oxygen (important for respiration by aquatic species),
• phosphate (an important plant nutrient which can cause blooms of algae when too high) and
• ammonia (which is often associated with recent sewage pollution).

Macroinvertebrates are small aquatic animals without skeletons, which provide a key food source for frogs, fish and the Platypus. Samples are taken monthly, and twice yearly, in late spring and late autumn, the data is added to the WaterWatch data portal. The species composition of these samples provides another indicator of stream health. Once all the equipment is set up and ready to go, approximately 10 minutes are spent gathering specimens from the creek. With waders on, a long-handled net and a few buckets, Denise entered the water. A new pair of waders was recently purchased with funds donated to the Friends – so, thank you! No more wet socks!

Denise, gathering specimens, photo by Jane Miller

Because it is necessary to enter the creek to collect the macroinvertebrates, this is only done if the water level is not considered too high for working safely. The rocks can be very slippery, and the flow can be quite fierce, making it easy to lose balance.

Along an approximately 10-metre stretch, different habitats are agitated to activate the various water bugs and send them into the net. Turning over rocks, swirling the net around reeds and along the edges of the creek, produces a few nets of species. These are then tipped into 2 flat plastic dishes to sort through, and the various species deposited in a specimen tray for counting.

   
Inspecting the samples; a spoonful of New Zealand Mud Snails, photos by Jane Miller

Numbers were down in this latest survey, for everything except the New Zealand Mud Snail, an invasive species. This could be due to changes in the habitat in the creek, or to competition with the Mud snail, or both.

If you would like to get involved, have a look at the list of Merri and tributary sites below, to find one near you. Always welcome!

More to explore:

WaterWatch Portal – data for Merri Creek ME_YMR112 Yarra River Catchment
WaterWatch (MCMC) – list of sites and contact details.
WaterWatch

Signage on the Merri Path.