If there was one switch we could flick that would ‘make native fish happen’ that would be great (!), but our research is telling us that we actually need to think about a range of different interacting factors – structural habitat (wood, riverbed, rocks, pools), connectivity, flow and hydrodynamics, and not all fish need the same conditions to thrive. Diversity is key, and we know complex structural habitats, connected floodplains, rivers and wetlands, with a mix of flows, promote biodiversity and resilient fish populations.
In regulated rivers, however, dams, weirs and water extraction simplify habitats and flow regimes, and disrupt connectivity. This has major impacts on the health of aquatic ecosystems, including fish. The latest edition of RipRap features a variety of articles that look in more detail at what constitutes flow, habitat and connectivity, and how these factors interact to support ecosystem function and healthy fish populations. A range of people have contributed to RipRap 39, with fisheries scientists, river restoration community groups and recreational fishers all providing insights into the work they are doing to understand what our native fish need to survive and thrive. RipRap 39 covers stories about using fish earbones (otoliths) to see where fish spawn and migrate, building ‘fish hotels’, providing environmental water to cue breeding, and protecting some of our smallest endangered native species.
A central theme to come out from the RipRap is that we need to be creating a mosaic of connected habitats that incorporate the complex flow characteristics of natural rivers at a range of spatial and temporal scales. Restoring ecologically relevant aspects of a river’s natural flow regime is fundamental to restoring the ecological health of regulated rivers, and there are some great examples in the magazine of where our interventions using environmental water are enabling this to happen.
If you care about Australia’s native fish and rivers then this edition of RipRap is a great way of getting up to date on the most recent research and practice. By purchasing a copy you are also helping the Australian River Restoration Centre promote and share the great work people are doing across the Basin.
Thankyou for your support,
(Editor RipRap Magazine)