Ecologist helps plan Tasmania's water use

A Massey University ecologist is helping researchers balance the needs of land use with the freshwater ecosystems in Tasmania.

Associate Professor Russell Death of the Institute of Natural Resources is working with University of Tasmania researchers to model the effects irrigation and climate change will have on waterways there.

Dr Death taught his Tasmanian colleagues the use of specialist modelling software during a trip last month.

“It models the relationships between flow and the biological measures that rate a waterway’s ecological health,” he says.

The software uses data to make predictions about what would happen in certain scenarios. “We can do things like model how the river level affects the number of a certain species of fish, for example. Then we can understand how a proposed hydro scheme, for example, will affect certain species within the waterways.”

Climate change factors also make up part of the study. “There’s no point spending large amounts of money in irrigation infrastructure if in 30-50 years time you do not end up with enough or alternatively too much water.”

Tasmania faces many of the same issues as New Zealand, with large-scale irrigation systems planned to meet growing needs in the agriculture and horticulture sectors. Dr Death is part of Massey’s Innovative River Solutions Centre, which brings together expertise from across the University to provide solutions to current river catchment and freshwater issues.

“Our goal is to balance the needs of agriculture and horticulture with the changing climate and the existing ecosystem.”

While in Tasmania, Dr Death also presented seminars on his freshwater biology research in New Zealand. “In Wairarapa, we have done the only replicated experimental manipulation of water abstraction in the world to look at ecosystem effects,” he says. “We also have a model of the relationship between land use and water quality that we have built for the Manawatu River.”

Dr Death hopes to set up collaborative research to compare the irrigation schemes in Tasmania to those planned for the east coast of the North Island.