We monitor the water quality at Williamstown Wetlands once each season.
Samples of water to measure the physical/chemical properties are taken from three different places across the wetlands:
- opposite the Arboretum bird hide
- the Causeway
- Caspian bridge
- pH - the acidity or alkalinity of the water. Pure water has a pH of 7.
- Electrical conductivity - the amount of dissolved salts in the water (salinity).
- Dissolved oxygen - the amount of oxygen dissolved in the water.
- Phosphorus (as phosphates) - necessary to support all forms of life, however high levels of phosphorus can be a problem resulting in algal growth.
- Ammonium - high levels can lead to unwanted algal growth.
- Turbidity - cloudiness of the water
- Temperature (air and water)
Using a large but fine-mesh net we collect macroinvertibrates from each of the two lakes. We record the number of different species collected and the number of individuals in each species.
Species can be grouped according to how sensitive they are to water pollution.
Very sensitive - Caddis fly larvae, mayfly nymphs
Sensitive - beetle larvae, diving beetles
Tolerant - damselfly nymphs, freshwater shrimp
Very tolerant - water boatman, freshwater snail