for those and other fish species. The work led to a far better understanding of carp control, factors affecting the numbers of fish in a river and their migrations (or not), predator–prey relationships in fish refuges, and the factors such as salinity and cold water pollution affecting the recruitment process in native fish species. Ben Gawne, Paul Humphries (MDFRC) and colleagues found strong evidence in lowland rivers of Victoria that warm slackwaters, in macrophyte beds or backwaters, act like incubators for native fish and water bugs. CRCFE studies by John Koehn (Dept of Sustainability and Environment, Vic), Paul Humphries and associates, suggested the spread of alien aquatic invaders is hindered more by natural flow regimes than by regulated flows.
Environmental Flow Regimes Environmental flows (e-flows) are an important ingredient in the management of healthy working rivers. The CRCFE and its partner organisations developed and strengthened both the concept and the science, with research and river management staff helping devise eflow regimes for rivers in Victoria, NSW, Queensland and the Australian Capital Territory, including the River Murray. The CRC tried to define the ways in which river ecosystems respond to flow regimes. It found there were often complex relationships, and discovered strong evidence that riparian plants and trees, fish, macroinvertebrates, waterbirds and microscopic organisms respond in a range of ways to various aspects of flow regimes. These observations added support for the hypothesis of many aquatic ecologists that flow is a key driver of ecological condition, including water quality, in rivers and floodplain wetlands.
Threatened Species CRCFE scientists were members of threatened species scientific committees Jane Hughes (Qld), Margaret Brock (NSW) and had input to the design and revision of the legislation for Commonwealth and State Acts. Angela Arthington took part in an international program of biodiversity science, DIVERSTAS. Increased awareness of the need for freshwater biodiversity conservation and a heritage river system were derived from the Fenner Conference and from other CRCFE publications such as Conserving Natural Rivers: A Guide for Catchment Managers (Cullen 2002) and Biodiversity in Inland Waters — Priorities for its protection and management (Georges and Cottingham 2002). Research on adaptive management in restoration ecology (C210) and in fish recovery (C220, C715) also fed into policy implementation. In 2004, Mark Kennard and Angela Arthington, with Brad Pusey, all of Griffith University, won the Whitley Award for zoological publishing, from the Royal Zoological Society of NSW, for their book Freshwater Fishes of Northeastern Australia.
Education
Rivers Survey
Almost 100 PhDs emerged from the two periods of the CRC. Many are now successful government water managers, technical specialists, consultants or research scientists.
The NSW Rivers Survey, led by John Harris and his team from NSW Fisheries, was a groundbreaking study that assessed the health of fish populations across the State. This showed that many rivers were degraded; especially the more heavily managed southern rivers of the Murray.
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