Filter articles by:
Date published
Article keywords
Article type

Small streams essential to freshwater ecology: UC expert

Marcus Butler

15 January 2018: Despite being on opposite sides of the globe, the Amazon is being used to challenge Australia’s conservation managers to pay more attention to their own backyard.

While the Amazon River is the largest in the world, its small streams and tributaries, which are less than three metres wide, make up 90 per cent of the total length of the watercourse.

University of Canberra Centenary Research Professor Ralph Mac Nally has co-authored an article examining the conservation of small streams in the Amazon basin.

The research, which has been published in the Journal of Applied Ecology, found that in regions where the Amazon is facing agricultural expansion, there is not enough consideration for the importance of small streams under Brazilian environmental law. Current laws focus mainly on forest protection but pay little attention to streams within the forests.

Professor Mac Nally, of the University’s Institute for Applied Ecology, said there are important lessons in the study for Australia.

"Up until now, terrestrial and freshwater ecosystems have tended to be managed separately, with little recognition of their crucial interdependence," Professor Mac Nally said.

"This work in Amazonia clearly shows the need for a unified management approach to whole catchments and river basins as integrated units to conserve effectively our plants and animals. Management of terrestrial areas and management of streams independently risk poor conservation outcomes."

Working alongside colleagues in Brazil, the United States, Sweden and the United Kingdom, Professor Mac Nally studied 83 small streams in two regions in the eastern Brazilian Amazon, which are undergoing extensive agricultural development.

"We found that these streams supported incredible levels of freshwater biodiversity," he said. "In a single 150 metre stretch of stream, there were more fish species than you will find in many countries.

"Streams that are a few dozen kilometres from each other can have completely different sets of species. What that means for conservation management and law-makers is that preserving just a few streams within a protected area is not enough to safeguard biodiversity."

Read the article Is environmental legislation conserving tropical stream faunas? A large-scale assessment of local, riparian and catchment-scale influences on Amazonian fish.