- Title
- An evaluation of the use of ecological indicators in a novel saltmarsh restoration project in the Hunter River, New South Wales, Australia
- Creator
- Rankin, Caleb James
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2023
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- Coastal ecosystems around the world have experienced historically high levels of loss and degradation over the past century due to increasing anthropogenic and environmental pressures. In South Eastern Australia, saltmarshes are at risk with up to 90% being lost in the past century and so are listed and protected as an endangered ecological community by the state of New South Wales, Australia. The loss of this habitat has seen a concomitant loss of ecological services for both ecosystem health and human benefit. To address these issues, the science and practice of ecological restoration has risen to prominence in recent decades along with an increasing understanding of the critical role healthy and productive ecosystems play in human and environmental wellbeing. However, with an increasing number of restoration projects around the world at various scales, there is a need quantify outcomes from restoration projects to ensure appropriate implementation and continued improvement ecological restoration. This study set out to address some of these issues by testing the usefulness and usability of a set of ecological indicators for saltmarsh restoration by identifying the development and health of saltmarsh systems using a novel saltmarsh restoration project in the Hunter River estuary, New South Wales, Australia. The project was implemented in 2016, using automated hydraulic control gates, termed ‘SmartGates’, to lower the tidal regime over one site (Area E), effectively reversing sea level rise at a local level. It was found that the restoration project at Area E was highly effective increasing a healthy and productive saltmarsh system with indicators rapidly moving towards those of comparison sites. Indicators of saltmarsh cover, macroinfauna diversity and abundances, and isotopic trophic niche size proved most useful for identifying improvements in saltmarsh health and productivity over two and a half years in relation to comparison sites over 2 and a half years. However, macroinfauna and trophic niche size indicators were among the most cost- and time-intensive indicators in this study requiring specialised skills and equipment and so potentially limiting their usefulness to researchers with access to appropriate skillsets, and substantial time and money. Tracking the abundances of the dominant gastropod species, such as Phalomedusa solida, Bembicum auratum and Ophicardelus ornatus, which had consistent temporal trends at Area E and became increasingly similar to comparison sites over me, could prove a less cost- and resource-intensive alternatve. Findings from this study highlight the usefulness of the novel dal restoration method used, with many indicators showing a convergence with comparison sites within two and a half years, and the strengths and weaknesses of various ecological indicators for assessing saltmarsh development. The vegetation indicators were shown to be particularly useful for local practitioners being economical and showing rapid development. Invertebrate indicators would be useful for researchers and consultants who want a fuller understanding of the developing diversity and functioning of the saltmarsh system. While less economical, stable isotope indicators were very useful for showing changes in saltmarsh productivity.
- Subject
- saltmarsh; ecological restoration; novel restoration; ecological indicators; indicator assessment
- Identifier
- http://hdl.handle.net/1959.13/1504243
- Identifier
- uon:55483
- Rights
- Copyright 2023 Caleb James Rankin
- Language
- eng
- Full Text
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Thesis | 33 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 6 MB | Adobe Acrobat PDF | View Details Download |