Developing geospatial tools to identify refuges from alien trout invasion in Australia to assist freshwater conservation

Marine and Freshwater Research, Journal Year: 2025, Volume and Issue: 76(4)

Published: Feb. 24, 2025

Context Introduced fish have caused significant range reductions for many native fish, with threatened species now found in headwater refuges, protected by in-stream barriers such as waterfalls, weirs and culverts. Owing to the remoteness of distribution is poorly understood despite urgency determining their because threats posed spread introduced into these refuges. Aims We investigated application emerging remote-sensing technology (LiDAR) improve our ability locate potential invasion identify Methods used LiDAR-derived digital elevation models find likely barriers, conducted surveys determine trout passability tributary headwaters. Key results Trout were rarely observed upstream waterfalls a gradient >0.82, whereas galaxiids only absence trout. Of 17 surveyed, 9 supported population upstream, 8 fishless. Implications LiDAR-based analysis an effective tool preliminary site selection prioritisation freshwater conservation. Discovery three new populations this study demonstrates technique additional trout-free streams, important other trout-sensitive aquatic species.

Language: Английский

The importance of off-river areas for fish in the mid- and lower Lachlan catchment of the Murray–Darling Basin, Australia: three case studies

Marine and Freshwater Research, Journal Year: 2025, Volume and Issue: 76(2)

Published: Jan. 23, 2025

Context There is increasing concern regarding the integrity of freshwater ecosystems at a global scale, and Australia’s Murray–Darling Basin an area where impacts river regulation invasive species are well-known documented. However, broad-scale assessments have generally occurred in main-channel habitats. Aims The study considers endangered fish communities off-river habitats specific catchment (the Lachlan) aims to demonstrate that these wetlands creeks may be important ecological areas lowland catchments. Methods data drawn from large number studies conducted since 2017; however, fish-sampling methodology has remained constant throughout (large small fyke nets set overnight). Key results Populations such as olive perchlet (Ambassis agassizii) catfish (Tandanus tandanus) persist certain locations within Lachlan catchment, water storages appear provide suitable habitat for sustaining resident populations broader range native species. Conclusion Off-river play roles inland riverine systems, research management often isolated pay dividends, especially given overall decline systems worldwide.

Language: Английский