Water Watch in 2003 at Bushy Park Wetlands

Parameter	Result	Comments
Ph or Acidity	7.1	Is exactly neutral, and perfect for all organisms.
Water Temp.	18.5°C	Air temp was 18.0°C, so water is fairly warm.
Turbidity	53 NTU	Considered to be degraded. A high turbidity means the water is very cloudy, which means it is hard for sunlight to reach the bottom of the water where water plants would live. Also high turbidity might affect some species of fish’s gills. European Carp which live in the wetlands do not mind this, in fact research has shown these fish actually increase the turbidity of the water.
Conductivity	210 uS/cm	For a river/wetland that is in a plain, this result is considered good. Conductivity is a measure of the total dissolved salts in the water. An area with high salinity would have a high conductivity, and cause problems for plants and animals.
Reactive Phosphates	0.58mg/L	This is very high, and so considered degraded. High phosphate levels can be caused by many factors including parent rock and in this case probably application of fertilisers in the catchment area.
Dissolved Oxygen	50 %	Oxygen is required for gill breathing creatures such as fish, yabbies and other macro-invertebrates. Plants also use oxygen when they respire at night. 50% means that the oxygen level is 50 % of what water can hold when completely saturated and cannot hold any more. This result is considered poor to fair.

As well as analyzing the chemistry of the water, scientists with Water Watch study the type and number of macro-invertebrates in the water. Macro-invertebrates are those tiny animals that we can see with the naked eye that have no backbone, or vertebral column. Some of these creatures live only in the cleanest of waters, whilst some can tolerate high levels of pollution. By recording the number of each animal type scientist can assess the cleanliness of the water.

In the water at Bushy Park Wetlands we found:

Hundreds of Water boatman bugs, which live in fairly polluted water. You may have found some of these in your backyard swimming pool.

3 Water snails, 1 bloodworm (which isn’t really a worm – it grows into those midges we see in summer). These can live in even more polluted water.

One Caddis fly larvae, an interesting animal that dresses up in a piece of reed for disguise. These creatures like mostly clean water.

Water Boatman picture
Water Boatman shown enlarged

Shannon and Tristan
Shannon & Tristan Lemanski shown identifying macro-invertebrates in a sample of water taken from the lake.

Overall the biodiversity level, calculated from the types and number of macro-invertebrates, is considered poor. We also caught 2 mosquito fish; a fish introduced to combat the high mosquito population, but it now devours just about every type of macro-invertebrate as well as tadpoles.

I would like to thank the Lemanski family that assisted the Friends of Bushy Park Wetlands on the day, Parks Victoria and a special thanks to Lisa Burkett from Monash Council for loaning the water testing kit for conducting the chemical testing.

By Rosemary Cowen, April 2003
A Friend of Bushy Park Wetlands.