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Advances in the aquatic sciences
RESEARCH ARTICLE (Open Access)

Assessment of the causes and solutions to the significant 2018–19 fish deaths in the Lower Darling River, New South Wales, Australia

F. Sheldon https://orcid.org/0000-0001-9944-6392 A G , D. Barma B , L. J. Baumgartner C , N. Bond D , S. M. Mitrovic E and R. Vertessy F
+ Author Affiliations
- Author Affiliations

A Australian Rivers Institute, Griffith University, Nathan, Qld 4111, Australia.

B Barma Water Consulting, Galston, NSW 2159, Australia.

C Institute for Land, Water and Society, Charles Sturt University, Albury, NSW 2640, Australia.

D Centre for Freshwater Ecosystems, La Trobe University, Wodonga, Vic. 3690, Australia.

E School of Life Sciences, University of Technology Sydney, Ultimo, NSW2007, Australia.

F School of Engineering, The University of Melbourne, Parkville, Vic. 3010, Australia.

G Corresponding author. Email: f.sheldon@griffith.edu.au

Marine and Freshwater Research 73(2) 147-158 https://doi.org/10.1071/MF21038
Submitted: 2 February 2021  Accepted: 12 August 2021   Published: 13 September 2021

Journal Compilation © CSIRO 2022 Open Access CC BY-NC-ND

Abstract

In late 2018 to early 2019, three significant fish death events occurred in the Lower Darling River, Australia, with mortality estimates of millions of fish. We examined the proximate and ultimate causes of these events. We determined that not only were the conditions existing at the time a significant contributing factor, but that antecedent conditions, particularly during the period 2010–17, also contributed. The extreme hot and dry climate during 2018, extending into 2019, shaped the conditions that saw a large fish biomass, which had flourished in the Darling River and Menindee Lakes since favourable spawning conditions in 2016, isolated in weir pools, with no means of escaping upstream or downstream. Strong and persistent weir pool stratification created hypoxic conditions in the hypolimnion. A series of sudden cool changes subsequently initiated rapid and sudden mixing of the stratified waters, causing depletion of oxygen throughout the water column and resulting in the fish deaths. The events were also shaped by broader climatic, hydrological and basin management contexts that placed the Lower Darling River at risk of such fish deaths. Our observations have implications for future river management, and we make several suggestions how policy makers and river operators can minimise fish death risks into the future.

Keywords: drought, fish deaths, thermal stratification, water resource development.


References

Abdel-Tawwab, M., Monier, M. N., Hoseinifar, S. H., and Faggio, C. (2019). Fish response to hypoxia stress: growth, physiological, and immunological biomarkers. Fish Physiology and Biochemistry 45, 997–1013.
Fish response to hypoxia stress: growth, physiological, and immunological biomarkers.Crossref | GoogleScholarGoogle Scholar | 30715663PubMed |

Australian Academy of Science (2019). Investigation of the causes of mass fish kills in the Menindee Region NSW over the summer of 2018–2019. Report of the Australian Academy of Science, Canberra, ACT, Australia. Available at https://www.science.org.au/files/userfiles/support/reports-and-plans/2019/academy-science-report-mass-fish-kills-digital.pdf

Baldwin, D. S. (2019). Stratification, mixing and fish deaths in the Lower Darling River. A report prepared for the Murray–Darling Basin Authority.

Baldwin, D. S. (2021). Water quality in the Murray–Darling Basin: The potential impacts of climate change. In ‘Murray–Darling Basin, Australia: Its Future Management’ (Eds. B. T. Hart, N. R. Bond, N. Byron, C. A. Pollino, and M. J. Stewardson), Elsevier, New York, pp. 137–159.

Baumgartner, L. J., Gell, P., Thiem, J. D., Finlayson, C. M., and Ning, N. (2020). Ten complementary measures to assist with environmental watering programs in the Murray–Darling river system, Australia. River Research and Applications 36, 645–655.
Ten complementary measures to assist with environmental watering programs in the Murray–Darling river system, Australia.Crossref | GoogleScholarGoogle Scholar |

Bonvechio, T. F., Allen, M. S., Gwinn, D., and Mitchell, J. S. (2011). Impacts of Electrofishing Removals on the Introduced Flathead Catfish Population in the Satilla River, Georgia. In ‘Conservation, Ecology, and Management of Catfish: The Second International Symposium’, dates, location. (Eds P. H. Michaletz and V. H. Travnichek), pp. 395–407. (American Fisheries Society: Bethesda, MD, USA.)

Boulton, A. J., Brock, M. A., Robson, B. J., Ryder, D. S., Chambers, J. M., and Davis, J. A. (2014). ‘Australian Freshwater Ecology: Processes and Management.’ (Wiley.)

Bowling, L., and Baker, P. (1996). Major cyanobacterial bloom in the Barwon–Darling River, Australia, in 1991, and underlying limnological conditions. Marine and Freshwater Research 47, 643–657.
Major cyanobacterial bloom in the Barwon–Darling River, Australia, in 1991, and underlying limnological conditions.Crossref | GoogleScholarGoogle Scholar |

Brown, R. S., Colotelo, A. H., Pflugrath, B. D., Boys, C. A., Baumgartner, L. J., Deng, Z. D., Silva, L. G. M., Brauner, C. J., Mallen-Cooper, M., Phonekhampeng, O., Thorncraft, G., and Singhanouvong, D. (2014). Understanding barotrauma in fish passing hydro structures: a global strategy for sustainable development of water resources. Fisheries 39, 108–122.
Understanding barotrauma in fish passing hydro structures: a global strategy for sustainable development of water resources.Crossref | GoogleScholarGoogle Scholar |

Chiew, F. H. S., Piechota, T. C., Dracup, J. A., and McMahon, T. A. (1998). El Nino/Southern Oscillation and Australian rainfall, streamflow and drought: links and potential forecasting. Journal of Hydrology 204, 138–149.
El Nino/Southern Oscillation and Australian rainfall, streamflow and drought: links and potential forecasting.Crossref | GoogleScholarGoogle Scholar |

Chiew, F. H. S., Teng, J., Vaze, J., Post, D. A., Perraud, J. M., Kirono, D. G. C., and Viney, N. R. (2009). Estimating climate change impact on runoff across southeast Australia: method, results, and implications of the modelling method. Water Resources Research 45, W10414.
Estimating climate change impact on runoff across southeast Australia: method, results, and implications of the modelling method.Crossref | GoogleScholarGoogle Scholar |

CSIRO and Australian Bureau of Meteorology (2020). State of the Climate 2020. http://www.bom.gov.au/state-of-the-climate/documents/State-of-the-Climate-2020.pdf

Ellis, I., and Meredith, S. (2004). An independent review of the February 2004 Lower Darling River fish deaths: guidelines for future release effects on Lower Darling River fish populations. Technical Report 7/2004, Murray–Darling Freshwater Research Centre, Mildura, Vic., Australia.

Ellis, I., Bates, W., Martin, S., McCrabb, G., Koehn, J., Heath, P., and Hardman, D. (2021). How fish kills affected traditional (Baakandji) and non-traditional communities on the Lower Darling–Baaka River. Marine and Freshwater Research. , .
How fish kills affected traditional (Baakandji) and non-traditional communities on the Lower Darling–Baaka River.Crossref | GoogleScholarGoogle Scholar |

Evans, A., Jones, D., Smalley, R., and Lellyett, S. (2020). An enhanced gridded rainfall analysis scheme for Australia. Bureau Research Report 41, Bureau of Meteorology, Melbourne, Vic, Australia.

Fellows, C. S., Clapcott, J., Udy, J., Bunn, S. E., Harch, B., Smith, M., and Davies, P. (2006). Benthic metabolism as an indicator of stream ecosystem health. Hydrobiologia 572, 71–87.
Benthic metabolism as an indicator of stream ecosystem health.Crossref | GoogleScholarGoogle Scholar |

Fellows, C. S., Bunn, S. E., Sheldon, F., and Beard, N. J. (2009). Benthic metabolism in two turbid dryland rivers. Freshwater Biology 54, 236–253.
Benthic metabolism in two turbid dryland rivers.Crossref | GoogleScholarGoogle Scholar |

Fey, S. B., Siepielski, A. M., Nussle, S., Cervantes-Yoshida, K., Hwan, J. L., Huber, E. R., and Carlson, S. M. (2015). Recent shifts in the occurrence, cause, and magnitude of animal mass mortality events. Proceedings of the National Academy of Sciences of the United States of America 112, 1083–1088.
Recent shifts in the occurrence, cause, and magnitude of animal mass mortality events.Crossref | GoogleScholarGoogle Scholar | 25583498PubMed |

Harris, R. M. B., Beaumont, L. J., Vance, T. R., Tozer, C. R., Remenyi, T. A., Perkins-Kirkpatrick, S. E., Mitchell, P. J., Nicotra, A. B., McGregor, S., Andrew, N. R., Letnic, M., Kearney, M. R., Wernberg, T., Hutley, L. B., Chambers, L. E., Fletcher, M. S., Keatley, M. R., Woodward, C. A., Williamson, G., Duke, N. C., and Bowman, D. M. J. S. (2018). Biological responses to the press and pulse of climate trends and extreme events. Nature Climate Change 8, 579–587.
Biological responses to the press and pulse of climate trends and extreme events.Crossref | GoogleScholarGoogle Scholar |

Harriss, D. (2012). Management of Menindee Lakes benefits all states. Water 39, 42–43.

Hart, B. T. (2016). The Australian Murray–Darling Basin Plan: factors leading to its successful development. Ecohydrology & Hydrobiology 16, 229–241.
The Australian Murray–Darling Basin Plan: factors leading to its successful development.Crossref | GoogleScholarGoogle Scholar |

Hoyer, M. V., Watson, D. L., Willis, D. J., and Canfield, D. E. (2009). Fish kills in Florida’s canals, creeks/rivers, and ponds/lakes. Journal of Aquatic Plant Management 47, 53–56.

Huang, S., Krysanova, V., Zhai, J., and Su, B. (2015). Impact of intensive irrigation activities on river discharge under agricultural scenarios in the semi-arid Aksu River Basin, Northwest China. Water Resources Management 29, 945–959.
Impact of intensive irrigation activities on river discharge under agricultural scenarios in the semi-arid Aksu River Basin, Northwest China.Crossref | GoogleScholarGoogle Scholar |

Koutrakis, E., Emfietzis, G., Sylaios, G., Zoidou, M., Katsiapi, M., and Moustaka-Gouni, M. (2016). Massive fish mortality in Ismarida Lake, Greece: identification of drivers contributing to the fish kill event. Mediterranean Marine Science 17, 280–291.
Massive fish mortality in Ismarida Lake, Greece: identification of drivers contributing to the fish kill event.Crossref | GoogleScholarGoogle Scholar |

La, V. T., and Cooke, S. J. (2011). Advancing the science and practice of fish kill investigations. Reviews in Fisheries Science 19, 21–33.
Advancing the science and practice of fish kill investigations.Crossref | GoogleScholarGoogle Scholar |

Lake, P. S. (2011). ‘Drought and Aquatic Ecosystems: Effects and Responses.’ (Wiley.)

Leigh, C., Sheldon, F., Kingsford, R. T., and Arthington, A. H. (2010). Sequential floods drive ‘booms’ and wetland persistence in dryland rivers: a synthesis. Marine and Freshwater Research 61, 896–908.
Sequential floods drive ‘booms’ and wetland persistence in dryland rivers: a synthesis.Crossref | GoogleScholarGoogle Scholar |

Lugg, A. (2000). ‘Fish Kills in NSW.’ (NSW Department of Primary Industries, Sydney, NSW, Australia.)

Mallen-Cooper, M., and Zampatti, B. P. (2020). Restoring the ecological integrity of a dryland river: why low flows in the Barwon–Darling River must flow. Ecological Management & Restoration 21, 218–228.
Restoring the ecological integrity of a dryland river: why low flows in the Barwon–Darling River must flow.Crossref | GoogleScholarGoogle Scholar |

Marsh, R., Petrie, B., Weidman, C. R., Dickson, R. R., Loder, J. W., Hannah, C. G., and Drinkwater, K. (1999). The 1882 tilefish kill – a cold event in shelf waters off the north-eastern United States? Fisheries Oceanography 8, 39–49.
The 1882 tilefish kill – a cold event in shelf waters off the north-eastern United States?Crossref | GoogleScholarGoogle Scholar |

Marti-Cardona, B., Steissberg, T. E., Schladow, S. G., and Hook, S. J. (2008). Relating fish kills to upwellings and wind patterns in the Salton Sea. Hydrobiologia 604, 85–95.
Relating fish kills to upwellings and wind patterns in the Salton Sea.Crossref | GoogleScholarGoogle Scholar |

McInnes, A. S., and Quigg, A. (2010). Near-annual fish kills in small embayments: casual vs. causal factors. Journal of Coastal Research 265, 957–966.
Near-annual fish kills in small embayments: casual vs. causal factors.Crossref | GoogleScholarGoogle Scholar |

Mitrovic, S., Bowling, L. C., and Buckney, R. T. (2001). Vertical disentrainment of Anabaena circinalis in the turbid freshwater Darling River, Australia: quantifying potential benefits from buoyancy. Journal of Plankton Research 23, 47–55.
Vertical disentrainment of Anabaena circinalis in the turbid freshwater Darling River, Australia: quantifying potential benefits from buoyancy.Crossref | GoogleScholarGoogle Scholar |

Mitrovic, S., Oliver, R. L., Rees, C., Bowling, L. C., and Buckney, R. T. (2003). Critical flow velocities for the growth and dominance of Anabaena circinalis in some turbid freshwater rivers Freshwater Biology 48, 164–174.
Critical flow velocities for the growth and dominance of Anabaena circinalis in some turbid freshwater riversCrossref | GoogleScholarGoogle Scholar |

Mitrovic, S., Hardwick, L., and Dorani, F. (2011). Use of flow management to mitigate cyanobacterial blooms in the Lower Darling River, Australia. Journal of Plankton Research 33, 229–241.
Use of flow management to mitigate cyanobacterial blooms in the Lower Darling River, Australia.Crossref | GoogleScholarGoogle Scholar |

Murray–Darling Basin Authority (2020). ‘Native Fish Recovery Strategy.’ (MDBA: Canberra, ACT, Australia.)

National Murray Cod Recovery Team (2010). National Recovery Plan for the Murray Cod Maccullochella peelii peelii. Department of Sustainability and Environment, Melbourne, Vic., Australia.

New South Wales Department of Primary Industries (2019). Fish death interim investigation report, Lower Darling River fish death event, Menindee 2018/19. NSW DPI.

Oliveira, G. A., Bailly, D., Cassemiro, F. A. S., Couto, E. V. D., Bond, N., and Gilligan, D. (2019). Coupling environment and physiology to predict effects of climate change on the taxonomic and functional diversity of fish assemblages in the Murray–Darling Basin, Australia. PLoS One 14, e0225128.
Coupling environment and physiology to predict effects of climate change on the taxonomic and functional diversity of fish assemblages in the Murray–Darling Basin, Australia.Crossref | GoogleScholarGoogle Scholar |

Peirson, W. L., and Laut, M. (2016). The future of dams in Eastern Australia. In ‘11th International Symposium on Ecohydraulics (ISE 2016)’, 7–12 February 2016, Melbourne, Vic, Australia. pp. 388–395. (Engineers Australia, Barton, ACT, Australia.)

Pitt, J. (2001). Can we restore the Colorado River delta? Journal of Arid Environments 49, 211–220.
Can we restore the Colorado River delta?Crossref | GoogleScholarGoogle Scholar |

Puckridge, J. T., Sheldon, F., Walker, K. F., and Boulton, A. J. (1998). Flow variability and the ecology of large rivers. Marine and Freshwater Research 49, 55–72.
Flow variability and the ecology of large rivers.Crossref | GoogleScholarGoogle Scholar |

Sharpe, C., and Stuart, I. (2018). ‘Environmental Flows in the Darling River to Support Native Fish Populations.’ (The Commonwealth Environmental Water Office.)

Starodubtsev, V. M., and Truskavetskiy, S. R. (2011). Desertification processes in the Ili River delta under anthropogenic pressure. Water Resources 38, 253.
Desertification processes in the Ili River delta under anthropogenic pressure.Crossref | GoogleScholarGoogle Scholar |

Thoms, M. C., and Sheldon, F. (2000). Water resource development and hydrological change in a large dryland river: the Barwon–Darling River, Australia. Journal of Hydrology 228, 10–21.
Water resource development and hydrological change in a large dryland river: the Barwon–Darling River, Australia.Crossref | GoogleScholarGoogle Scholar |

Tonkin, J. D., Poff, N. L., Bond, N. R., Horne, A., Merritt, D. M., Reynolds, L. V., Olden, J. D., Ruhi, A., and Lytle, D. A. (2019). Prepare river ecosystems for an uncertain future. Nature 570, 301–303.
Prepare river ecosystems for an uncertain future.Crossref | GoogleScholarGoogle Scholar | 31213691PubMed |

van Dijk, A. I. J. M., Beck, H. E., Crosbie, R. S., de Jeu, R. A. M., Liu, Y. Y., Podger, G. M., Timbal, B., and Viney, N. R. (2013). The Millennium Drought in southeast Australia (2001–2009): natural and human causes and implications for water resources, ecosystems, economy, and society. Water Resources Research 49, 1040–1057.
The Millennium Drought in southeast Australia (2001–2009): natural and human causes and implications for water resources, ecosystems, economy, and society.Crossref | GoogleScholarGoogle Scholar |

Vertessy, R., Barma, D., Baumgartner, L., Bond, N. R., Mitrovic, S., and Sheldon, F. (2019). Independent Assessment of the 2018–19 fish deaths in the Lower Darling. Murray–Darling Basin Authority and Australian Government, Australia.

Vörösmarty, C. J., McIntyre, P. B., Gessner, M. O., Dudgeon, D., Prusevich, A., Green, P., Glidden, S., Bunn, S. E., Sullivan, C. A., Liermann, C. R., and Davies, P. M. (2010). Global threats to human water security and river biodiversity. Nature 467, 555–561.
Global threats to human water security and river biodiversity.Crossref | GoogleScholarGoogle Scholar | 20882010PubMed |

Wells, H. W., Wells, M. J., and Gray, I. E. (1961). Winter fish mortality in Pamlico Sound, North Carolina. Ecology 42, 217–219.
Winter fish mortality in Pamlico Sound, North Carolina.Crossref | GoogleScholarGoogle Scholar |

Yang, Y., McVicar, T. R., Donohue, R. J., Zhang, Y., Roderick, M. L., Chiew, F. H. S., Zhang, L., and Zhang, J. (2017). Lags in hydrologic recovery following an extreme drought: assessing the roles of climate and catchment characteristics. Water Resources Research 53, 4821–4837.
Lags in hydrologic recovery following an extreme drought: assessing the roles of climate and catchment characteristics.Crossref | GoogleScholarGoogle Scholar |