Estuarine habitats and impacts

The estuarine habitats and impacts theme incorporates experimental research and large-scale monitoring program to inform best practice management and improved understanding of coastal and marine species and ecosystems.

The theme discriminates natural fluctuations in habitats and species from changes caused by to human disturbances and find solutions for mitigating impacts. Projects consider current impacts and potential future impacts that might occur with climate change.

Our research develops new knowledge that supports healthy habitats and allows our coastal and marine ecosystems to be managed into the future. The theme Estuarine habitat and impacts is led by Dr Tim Glasby.

Research focus

Research under the Estuarine impacts theme supports the Marine Estate Management Strategy by providing data and information to support the Marine Integrated Monitoring Program (MIMP).

Within this research area we look at:

  • Identify changes in estuarine habitats over time and how these might relate to human impacts
  • Investigate how best to restore seagrass habitats
  • Use long-term monitoring and experiments to establish cause and effect relationships, to test policy and management options

Current projects

Monitoring estuarine habitats and disturbances

Seagrasses, mangroves and saltmarshes are threatened by a range of human disturbances including boating activities, foreshore modifications, grazing and land clearing.  This project tracks changes in the extent and condition of these estuarine habitats and identifies where in the state macrophytes are at most risk, thereby enabling management initiatives to be better targeted. It utilises artificial intelligence techniques to improve mapping and habitat assessments. The latest mapped data can be viewed and downloaded on the Fisheries Spatial Data Portal and the complete historic data set as well as mapped disturbances and artificial structures can be viewed on the NSW Estuarine Habitat Dashboard.
Tim Glasby, Greg West, Daniel Swadling, Peter Gibson, Brooke McCartin, Roger Laird

Effects of future climate on the seagrass Posidonia australis

As our climate changes, there will be more frequent intense rainfall events on the east coast, resulting in repeated low salinity events and increased turbidity in estuaries. Seagrasses can tolerate short pulses of reduced salinity and light, but we know little about their ability to withstand repeated stressful events. This project, funded by the NSW Environmental Trust will involve aquarium experiments to test the combined impacts of low salinity and light on the threatened seagrass Posidonia australis and the species’ ability to recover. In association with University of WA researcher Dr Liz Sinclair, we will use genetic studies to identify whether certain populations of Posidonia are naturally more tolerant of these stressful conditions, meaning they could be used as sources for restoration programs to help future-proof this threatened seagrass. Tim Glasby Daniel Swadling, Matt Nimbs, Brooke McCartin

How do sediments and microbes influence seagrass growth and condition?

This is an ARC-Linkage project involving numerous researchers from led by University of NSW, University of Sydney, Macquarie University, University of WA.  The project aims will investigate the role that microbes in sediments play in influencing seagrass survival and growth.  Results will help optimise future seagrass restoration methods and assist with understanding impacts to seagrasses and the extent to which microbes could help ameliorate these. Tim Glasby

Understanding changes in shallow rocky reef habitats across NSW

This research program  documents the changes through time in particular reef habitats (primarily the green seaweed Caulerpa filiformis and urchin-grazed ‘barrens’) and investigates the potential drivers for this and the ecological ramifications.  Projects include collaborations with the University of NSW. Tim Glasby

Key publications

Swadling D. S., West G. J., Gibson P. T., Laird R. J. and Glasby T. M. (2023) Multi-scale assessments reveal changes in the distribution of the endangered seagrass Posidonia australis and the role of disturbances. Marine Biology 170, p.147

Glasby T. M., Gibson P. T., Laird R., Swadling D. S. and West G. (2023) Black summer bushfires caused extensive damage to estuarine wetlands in New South Wales, Australia. Ecological Management & Restoration 24, 27-35.

Wen L., Glasby T. M. and Hughes M. G. (2023) The race for space: modelling the landward migration of coastal wetlands under sea level rise at a regional scale. Science of the Total Environment 859, 160483.

Swadling D. S., West G. J., Gibson P. T., Laird R. J. and Glasby T. M. (2023) Don't go breaking apart: Anthropogenic disturbances predict meadow fragmentation of an endangered seagrass. Aquatic Conservation: Marine and Freshwater Ecosystems 33, 56-69.

Rees M. J., Knott N. A., Astles K., Swadling D. S., West G. J., Ferguson A., Delamont J., Gibson P. T., Neilson J., Birch G. and Glasby T. M. (2023) Cumulative effects of multiple stressors impact an endangered seagrass population and fish communities. Science of the Total Environment 904, 166706.

Mayer-Pinto M., Bugnot A. B., Johnston E. L., Potts J., Airoldi L., Glasby T. M., Strain E. A., Scanes P., Ushiama S. and Dafforn K. A. (2023) Physcial and biogenic complexity mediates ecosystem functions in urban sessile marine communities. Journal of Applied Ecology 60, 480– 493.

Ferretto G., Verges A., Poore A. G. B., Glasby T. M. and Griffen K. (2023) Habitat provision and erosion are influenced by seagrass meadow complexity: a seascape perspective. Diversity 15, 125.

Ferretto G., Glasby T. M., Poore A. G. B., Callaghan C. T., Sinclair E. A., Statton J., Kendrick G. A. and Verges A. (2023) Optimizing the restoration of the threatened seagrass Posidonia australis: plant traits influence restoration success. Restoration Ecology 31, e13893.

Hughes M. G., Glasby T. M., Hanslow D., West G. and Wen L. (2022) Random forest classification method for predicting intertidal wetland migration under sea level rise. Frontiers in Marine Science 10, 749950.

Ferretto G., Verges A., Poore A. G. B., Gribben P. E. and Glasby T. M. (2022) Floating bags have the potential to minimise oyster farming impacts on Posidonia australis seagrass meadows. Aquaculture 560, 738594.

West G. and Glasby T. M. (2021) Interpreting long-term patterns of seagrasses abundance: how seagrass variability is dependent on genus and estuary type. Estuaries and Coasts 45, 139-1408.

Voerman S. E., Gribben P. E. and Glasby T. M. (2021) Positive and negative species interactions shape recruitment patterns of a range expanding native alga. Frontiers in Marine Science 8.

Ferretto G., Glasby T. M., Poore A. G. B., Callaghan C., Housefield G. P., Langley M., Sinclair E. A., Statton J., Kendrick G. A. and Verges A. (2021) Naturally-detached fragments of the endangered seagrass Posidonia australis collected by citizen scientists can be used to successfully restore fragmented meadows. Biological Conservation 262, 10930.

Bradley D. J., Boada J., Gladstone W., Glasby T. M. and Gribben P. E. (2021) Sublethal effects of a rapidly spreading native alga on a key herbivore. Evolution and Ecology 11, 12605–12616.