Flow to nowhere: the disconnect between environmental watering and the conservation of threatened species in the Murray–Darling Basin, Australia

Abstract

The Murray-Darling Basin Plan was established with the objective of restoring water from irrigation to the environment, thereby conserving wetlands and biodiversity. We examined whether the Plan is achieving this objective by assessing whether environmental watering has helped conserve threatened flow-dependent fauna. Two frog species, two waterbirds and four fishes, were assessed for their conservation status in relation to (1) whether they were targeted in environmental watering plans, (2) whether population monitoring had occurred and (3) evidence of population recovery. We determined indicators of abundance and occurrence of species between 2012-13 and 2018-19 and found widespread inconsistencies in the targeting of environmental watering for these species, including their being overlooked in watering plans and actions in several catchments. Environmental watering had some positive outcomes for some threatened species in some locations on some occasions, but benefits, and their monitoring and reporting, are patchy and inconsistent. Monitoring of temporal trends in distribution, occurrence and abundance of species is inadequate to evaluate success. If the Plan is to achieve its objective and uphold Australia's international environmental treaty obligations, more needs to be done to target and deliver environmental water for threatened species and improve the monitoring and reporting of outcomes.

Failure to achieve recommended environmental flows coincides with declining fish populations: Long‐term trends in regulated and unregulated rivers

“…Thus, the ability to positively impact native species with e‐flows might diminish over time; particularly in systems where human use and climate change limit the amount of water available to implement e‐flows (Bruckerhoff et al, 2022; Horne et al, 2019; Wineland et al, 2021). Few empirical tests of e‐flow implementations exist because of a lack of long‐term biological and hydrological data (Davies et al, 2014; Ryan et al, 2021), and it is possible that attempting to mimic or protect natural flow regimes will not completely compensate for the effects of other stressors on riverine ecosystems (e.g., non‐native species, water quality, habitat changes; Propst et al, 2008; McManamay et al, 2013; Thompson et al, 2018), especially if flow reductions from consumptive water use and climate change continue. Long‐term data on flow and biotic responses are critical for evaluating the effectiveness of e‐flows, and we demonstrate that failing to prioritise e‐flows has clear implications for native fishes.…”

Enhancing whole-of-river conservation

“…This might be achieved by providing NRM bodies with stronger legislative and regulatory frameworks for sustainable management or creation of independent management authorities with appropriate powers. Such an approach was embodied in the establishment of the Murray-Darling Management Authority and associated legislation, but its progress has been beset by substantial failures, partly owing to interstate disagreement and vested interests (Beasley 2021;Chen et al 2021;Ryan et al 2021). Catchments within states should not have transboundary problems.…”

Climate change adaptation planning for an internationally important wetland, the Muir–Byenup System Ramsar Site in south-west Australia

“…The knowledge base about environmental flow requirements and mechanisms developed in highly regulated systems, such as most of the Murray-Darling Basin, Australia, may provide useful insights for many Ramsar wetlands once the information becomes more widely available. Although some information has recently been published on the use of environmental flows in the Murray-Darling Basin (Koehn et al 2020), there are also concerns that these measures may not be as effective as anticipated (Chen et al 2021;Kirsch et al 2021;Ryan et al 2021). There is every possibility though that the adoption of complementary measures to assist with the restoration of the rivers and wetlands in the Murray-Darling Basin (Baumgartner et al 2020) may provide synergies with the 'no regrets' adaptation measures mentioned above.…”