If the shrimps, mayflies and caddis flies of the Kangaroo River catchment feel spied upon over the next couple of years, it may well be Kate Smolders peering into their miniature world.

Kate is undertaking a doctoral study that might provide a biological tool for measuring the health of streams to add to the current collection of physical and chemical indicators of stream condition.

Her study will examine selective harvesting in native hardwood forest using a multi catchment experiment investigating the effects on aquatic biota, ecosystem processes and stream function in the head waters of the Kangaroo River, north west of Coffs Harbour.

“I am fascinated with the invertebrates, as they and their various life stages are so different from us and other vertebrate animals,” Kate says.

She comes to this experiment with a degree in environmental science from the University of New England, and then several years as a research assistant in ecology with Griffith University in Brisbane.

Kate has accepted an Australian Post Graduate Award funded by the federal government to undertake this study for Forests NSW, which is also providing financial and in-kind support for the three years of the project.

“I will be looking at the biota in five streams in Kangaroo River State Forest that will be subject to various regimes of nearby forest harvesting and post harvest burning,” Kate said.

“Two of the streams will be in forest that will be undisturbed over the length of the trial.”

“Two others will be subject to usual native forest harvesting with post harvest burns, and the third is yet to be determined.”

“I will measure the changes, if any, in aquatic invertebrate communities every two months for two years.”

“There are a number of invertebrates, including mayflies and caddis flies, that are sensitive to sediment levels in water, and the presence or absence of these could be a good indicator of overall stream health.”

Kate said there had been few, if any, published Australian studies of the biological effects of selective harvesting on stream life.

“There have been studies in Canada and the United States of America, but their forest regime is different from Australian forests,” Kate said.

“They may have pronounced seasonal changes, including snow melt, and a single autumnal leaf fall that adds vegetative mass to streams, but in Australia the eucalypt leaf fall is consistent virtually all year round, and rather than snow melt, we are likely to experience low or even non-existent stream flows.”

Kate could well add new invertebrates to the known list, as there are many that already exist in streams that have not been described in science.

The outcomes of Kate’s study could provide Forests NSW with new tools to assess stream health, adding to existing assessment tools used for stream turbidity, temperature, stream flow and rainfall.

“The results of this study will improve measures to protect aquatic biodiversity and ecosystem function, and provide a firmer scientific basis for ecologically sustainable harvesting in this forest type,” Kate said.

This article appears in the Summer 2006 edition of Bush Telegraph Magazine.