Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences
RESEARCH ARTICLE

From fresh to saline: a comparison of zooplankton and plant communities developing under a gradient of salinity with communities developing under constant salinity levels

Daryl L. Nielsen A B D , Margaret A. Brock B C , Matthew Vogel A and Rochelle Petrie A
+ Author Affiliations
- Author Affiliations

A Murray-Darling Freshwater Research Centre, Wodonga, Vic. 3690, Australia.

B Co-operative Research Centre for Freshwater Ecology, Canberra, ACT 2601, Australia.

C Environmental and Rural Sciences, University of New England, Armidale, NSW 2351, Australia.

D Corresponding author. Email: daryl.nielsen@csiro.au

Marine and Freshwater Research 59(7) 549-559 https://doi.org/10.1071/MF07166
Submitted: 20 September 2007  Accepted: 9 April 2008   Published: 24 July 2008

Abstract

In Australia, many freshwater wetlands are becoming saline. Knowing which elements of a biotic community will persist as wetlands turn saline is relevant to their future management. We simulated gradual and sudden increases in salinity in outdoor mesocosms to test the hypotheses that: (1) aquatic plant and zooplankton communities exposed to a gradient of increasing salinity over time would initially resemble freshwater communities, but as the salinity increased they would resemble communities found in more saline systems; and (2) that a gradual change in salinity over 6 months influences zooplankton and plant communities in the same way as a sudden salinity change. Below 1000 mg L–1, as salinity increased gradually, communities rich in species and numbers of individuals resembled freshwater communities. However, as the salinity exceeded 1000 mg L–1, taxa were progressively lost and communities became less diverse. When salinities exceeded 3000 mg L–1 the diversity decreased rapidly and few taxa remained at 5000 mg L–1. Both sudden and gradual increases in salinity induced similar decreases in diversity. We predict that as natural wetlands become more saline, few freshwater biota will survive once the salinity exceeds 5000 mg L–1. In the long term, such salinised wetlands would need to be recolonised by salt-tolerant taxa for a functional wetland to persist.


Acknowledgements

We acknowledge the financial and facility support of the Co-operative Research Centre for Freshwater Ecology and the Murray-Darling Freshwater Research Centre (MDFRC) in the conducting of this research project. The experiments took place while MAB was employed by the NSW Department of Natural Resources whose functions from 2007 were incorporated into The NSW Department of Climate Change and Conservation. The mesocosm experiments were conducted at the Wonga Wetlands, an Albury Council facility. We thank Paul Wettin and Bruce Cooper for helping to define the management questions that our research aims to address. We would also like to acknowledge the assistance provided by Peter McClellan (Bluelight Lagoon, Macquarie Marshes) in collecting the sediment and to thank Dr Gavin Rees and the salinity project team for their assistance in the setting up and operation of this project and members of the MDFRC writers group for their comments on this manuscript. We also thank Dr Bob Clarke from Plymouth Marine Laboratories for advice and assistance with the multivariate analysis.


References

Anderson, M. J. (2001). A new method for non-parametric multivariate analysis of variance. Austral Ecology 26, 32–46.
CrossRef |

Anderson M. J. , and Gorley R. N. (2008). ‘PERMANOVA+ for PRIMER: Guide to Software and Statistical Methods.’ (PRIMER-E: Plymouth.)

Australian Nature Conservation Agency (1996). ‘A Directory of Important Wetlands in Australia.’ 2nd edn. (ANCA: Canberra.)

Britton, D. L. , and Brock, M. A. (1994). Seasonal germination from wetland seed banks. Australian Journal of Marine and Freshwater Research 45, 1445–1457.
CrossRef |

Brock, M. A. (1981). The ecology of halophytes in salt lakes in the south-east of South Australia. Hydrobiologia 81–82, 23–32.
CrossRef |

Brock, M. A. (1985). Are Australian salt lake ecosystems different? Evidence from the submerged aquatic plant communities. Proceedings of the Ecological Society of Australia 14, 43–50.


Brock M. A. (1986). Adaptations to fluctuations rather than to extremes of environmental parameters. In ‘Limnology in Australia’. (Eds P. De Deckker and W. D. Williams.) pp. 131–140. (CSIRO/Junk: Melbourne/Dordecht.)

Brock, M. A. , and Lane, J. A. K. (1983). The aquatic macrophyte flora of saline wetlands in Western Australia in relation to salinity and permanence. Hydrobiologia 105, 63–76.


Brock, M. A. , and Shiel, R. J. (1983). The composition of aquatic communities in saline wetlands in Western Australia. Hydrobiologia 105, 77–84.
CrossRef |

Brock, M. A. , Nielsen, D. L. , Shiel, R. J. , Green, J. D. , and Langley, J. D. (2003). Drought and aquatic community resilience: the role of eggs and seeds in sediments of temporary wetlands. Freshwater Biology 48, 1207–1218.
CrossRef |

Brock, M. A. , Nielsen, D. L. , and Crosslé, K. (2005). Changes in biotic communities developing from freshwater wetland sediments under experimental salinity and water regimes. Freshwater Biology 50, 1376–1390.
CrossRef |

Clarke R. M. , and Warwick K. R. (2001). ‘Change in Marine Communities: An Approach to Statistical Analysis and Interpretation.’ 2nd edn. (PRIMER-E: Plymouth.)

Cramer, V. A. , and Hobbs, R. J. (2002). Ecological consequences of altered hydrological regimes in fragmented ecosystems in southern Australia: impacts and possible management responses. Austral Ecology 27, 546–564.
CrossRef |

Cramer, V. A. , and Hobbs, R. J. (2005). Assessing the ecological risk from secondary salinity: a framework addressing questions of scale and threshold responses. Austral Ecology 30, 537–545.
CrossRef |

Davis, J. A. , McGuire, M. , Halse, S. A. , Hamilton, D. , Horwitz, P. , McComb, A. J. , Froend, R. H. , Lyons, M. , and Sim, L. (2003). What happens when you add salt: predicting impacts of secondary salinisation on shallow aquatic ecosystems by using an alternative-states model. Australian Journal of Botany 51, 715–724.
CrossRef |

Gray, D. K. , Bailey, S. A. , Duggan, I. C. , and Macisaac, H. J. (2005). Viability of invertebrate diapausing eggs exposed to saltwater: implications for Great Lakes’ ship ballast management. Biological Invasions 7, 531–539.
CrossRef |

Green, J. , and Mengestou, S. (1991). Specific diversity and community structure of Rotifera in a salinity series of Ethiopian inland waters. Hydrobiologia 209, 95–106.


Hammer U. T. (1986). ‘Saline Lake Ecosystems of the World.’ (W. Junk: Dordrecht.)

Harden G. J. (1993). ‘Flora of NSW Volumes 1–4.’ (New South Wales University Press: Kensington.)

Hart, B. T. , Bailey, P. , Edwards, R. , Hortle, K. , James, K. , McMahon, A. , Meredith, C. , and Swadling, K. (1991). A review of the salt sensitivity of the Australian freshwater biota. Hydrobiologia 210, 105–144.


Hobbs, R. J. , Cramer, V. A. , and Kristjanson, L. J. (2003). What happens if we cannot fix it? Triage, palliative care and setting priorities in salinising landscapes. Australian Journal of Botany 51, 647–653.
CrossRef |

James, K. R. , and Hart, B. T. (1993). Effect of salinity on four freshwater macrophytes. Australian Journal of Marine and Freshwater Research 44, 769–777.
CrossRef |

James, K. R. , Cant, B. , and Ryan, T. (2003). Responses of freshwater biota to rising salinity levels and implications for saline water management: a review. Australian Journal of Botany 51, 703–713.
CrossRef |

Kefford, B. J. , Papas, P. J. , and Nugegoda, D. (2003). Relative salinity tolerance of macroinvertebrates from the Barwon River, Victoria, Australia. Marine and Freshwater Research 54, 755–765.
CrossRef |

Kefford, B. J. , Nugegoda, D. , Metzeling, L. , and Fields, E. J. (2006). Validating species sensitivity distributions using salinity tolerance of riverine macroinvertebrates in the southern Murray-Darling Basin (Victoria, Australia). Canadian Journal of Fisheries and Aquatic Sciences 63, 1865–1877.
CrossRef |

Kefford, B. J. , Fields, E. J. , Clay, C. , and Nugegoda, D. (2007). Salinity tolerance of riverine microinvertebrates from the southern Murray-Darling Basin. Marine and Freshwater Research 58, 1019–1031.
CrossRef |

Kingsford, R. T. , and Porter, J. L. (1994). Waterbirds on an adjacent freshwater lake and salt lake in arid Australia. Biological Conservation 69, 219–228.
CrossRef |

Nielsen, D. L. , Hillman, T. J. , Smith, F. J. , and Shiel, R. J. (2002). The influence of seasonality and duration of flooding on zooplankton in experimental billabongs. River Research and Applications 18, 227–237.
CrossRef |

Nielsen, D. L. , Brock, M. A. , Crosslé, K. , Harris, K. , Healey, M. , and Jarosinski, I. (2003a). The effects of salinity on aquatic plant germination and zooplankton hatching from two wetland sediments. Freshwater Biology 48, 2214–2223.
CrossRef |

Nielsen, D. L. , Brock, M. A. , Rees, G. N. , and Baldwin, D. S. (2003b). Effects of increasing salinity on freshwater ecosystems in Australia. Australian Journal of Botany 51, 655–665.
CrossRef |

Nielsen, D. L. , Watson, G. , and Petrie, R. (2005). Microfaunal communities in three lowland rivers under differing flow regimes. Hydrobiologia 543, 101–111.
CrossRef |

Nielsen, D. L. , Brock, M. A. , Petrie, R. , and Crosslé, K. (2007). The impact of salinity pulses on the emergence of plant and zooplankton from wetland seed and egg banks. Freshwater Biology 52, 784–795.
CrossRef |

Pinder, A. M. , Halse, S. A. , McRae, J. M. , and Shiel, R. J. (2005). Occurrence of aquatic invertebrates of the wheatbelt region of Western Australia in relation to salinity. Hydrobiologia 543, 1–24.
CrossRef |

Sainty G. R. , and Jacobs S. W. L. (1981). ‘Waterplants of New South Wales.’ (Water Resources Commission: Sydney.)

Sarma, S. S. S. , Elguea-Sánchez, B. , and Nandini, S. (2002). Effect of salinity on competition between the rotifers Brachionus rotundiformis Tschugunoff and Hexarthra jenkinae (De Beauchamp) (Rotifera). Hydrobiologia 474, 183–188.
CrossRef |

Sarma, S. S. S. , Nandini, S. , Morales-Ventura, J. , Delgado-Martínez, I. , and González-Valverde, L. (2006). Effects of NaCl salinity on the population dynamics of freshwater zooplankton (rotifers and cladocerans). Aquatic Ecology 40, 349–360.
CrossRef |

Shiel R. J. (1995). ‘A Guide to Identification of Rotifers, Cladocerans and Copepods from Australian Inland Waters.’ (Co-operative Research Centre for Freshwater Ecology: Canberra.)

Sim, L. L. , Chambers, J. M. , and Davis, J. (2006). Ecological regime shifts in salinised wetlands systems. I. Salinity thresholds for the loss of submerged macrophytes. Hydrobiologia 573, 89–107.
CrossRef |

Strehlow, K. , Davis, J. , Sim, L. , Chambers, J. , Halse, S. , Hamilton, D. , Horwitz, P. , McComb, A. , and Froend, R. (2005). Temporal changes between ecological regimes in a range of primary and secondary salinised wetlands. Hydrobiologia 552, 17–31.
CrossRef |

Timms, B. V. (1993). Saline lakes of the Paroo, inland New South Wales, Australia. Hydrobiologia 267, 269–289.
CrossRef |

Warwick, N. W. M. , and Bailey, P. C. E. (1997). The effect of increasing salinity on the growth and ion content of three non-halophytic wetland macrophytes. Aquatic Botany 58, 73–88.
CrossRef |

Warwick, N. W. M. , and Bailey, P. C. E. (1998). The effect of time exposure to NaCl on leaf demography and growth of two non halophytic wetland macrophytes, Potamogeton tricarinatus F. Muell. and A. Benn. Ex A. Benn. and Triglochin procera R.Br. Aquatic Botany 62, 19–31.
CrossRef |

Williams, W. D. (1998). Salinity as a determinant of the structure of biological communities in salt lakes. Hydrobiologia 381, 191–201.
CrossRef |



Rent Article (via Deepdyve) Export Citation Cited By (11)

View Altmetrics