Monitoring ecological water – impacts from disturbance

Bob Brown Foundation has successfully introduced new techniques for identifying endangered species – including Tasmanian Masked Owls and Swift Parrots – by recording and analysing audio recordings. It has led to successful court action to halt destruction of vital habitats for these species.

The Foundation is seeking to buy a water quality probe to measure a range of physico-chemical metrics before and after logging or mining disturbances in streams and water bodies near or inside logging coupes.
These will be compared with the national critical ‘trigger’ and guideline values from the EPA. The approach will measure: dissolved oxygen, conductivity pH, and water temperature.

Study #1: Water quality — physico-chemical assessment
Context: The water quality standards and ranges relevant to the EPBC Act are generally defined by Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC Guidelines). The ANZECC Guidelines provide recommended water
quality indicator values for protecting aquatic ecosystems, including freshwater and marine environments. These values are designed to help manage water quality to sustain biodiversity, ecosystem function, and protect water-dependent species. For freshwater quality, the ANZECC guidelines focus on various indicators such as pH, dissolved oxygen, turbidity, nutrients (nitrogen
and phosphorus), metals, and others. These values are categorized as either trigger values (used as indicators of water quality) or guideline values (protecting specific ecosystem health or species).

Study #2: Impact of the Forestry burns on river living organisms

Context: Every Autumn, Forestry Tasmania fire-bombs large areas that were recently clearfelled. The impact that these burns would have on water bugs is potentially catastrophic but has not been quantified by an independent study. These macroinvertebrates are crucial for the biodiversity of the down-stream waterways. The temperature that the stream can get to could lead to direct mortality of macroinvertebrates. This temperature varies depending on the species but, as a lot of animals in Tasmania are more adapted to cool water, the impact is possibly relatively high. Small streams are probably the most affected. Small streams are very important as they often have higher differences in biodiversity compared to large streams, they ‘feed’ bugs into bigger waterways. In addition, lots of ash and burnt dead wood in the streams directly post-fire will likely temporarily reduce habitat for water bugs and alter how nutrients are cycled. The degree of this effect will depend on the size of the riverside forest margin and how impacted this is by fire.

BBF is seeking in this project to:
– Conduct a before / after study of macroinvertebrate diversity

– Monitor the water quality of water streams before, during and after forestry or mining operations

Image credit: Adam Harvey