Water is the most fundamental requirement for fish; however fish won’t survive unless their habitat, food, and life-cycle requirements are also met. Environmental flows can contribute to restoring more natural flow regimes and variability within aquatic habitats. They can also increase connectivity, enhance productivity and improve water quality. The potential to achieve more sustainable long-term ecological outcomes through improved water management may be further enhanced by undertaking parallel complementary actions that address additional threats to native fish. These additional activities include (amongst others) habitat restoration and enhancement (e.g. re-snagging, instream and riparian zone management); mitigating cold water pollution or hypoxic black water impacts; improving fish passage and connectivity; screening diversions to minimise fish entrainment; pest species control, and; conservation stocking or translocations in cases where native species are unlikely or unable to recolonise rehabilitated habitats.
As part of recent water management activities, NSW DPI Fisheries staff are trialing a range of associated complementary actions including manipulation of wetland hydrology, inlet screening (to exclude colonisation by adult carp, and thus improve water quality and promote macrophyte health) and stocking or translocation of native fish. These complementary actions aim to support native fish outcomes from improved environmental water management in the lower Murray River reaches of NSW. Some outcomes of these activities will be explored, demonstrating how native fish benefits can be enhanced by water managers, land managers and fish ecologists working together to return native fish to the Murray-Darling Basin.