Home > T&I Project - Component 2. Aquatic Plants and Algae

Component Summary

This research project is one of five components delivered by the Goyder Institute for the Department for Environment and Water’s Healthy Coorong, Healthy Basin Scientific Trials and Investigations Project.

In this component a restoration strategy will be developed to guide aquatic plant refugia establishment and restoration of the Coorong as a whole. This research will enhance restoration activities for returning Ruppia to dominate the aquatic habitat of the Coorong.

The research will help in understanding how different (existing) management options might limit filamentous algae distribution and abundance and restore aquatic plant distribution, abundance and resilience in the Coorong.

Component Detail

Ruppia tuberosa (Ruppia) is a keystone species for the southern Coorong – contributing to maintaining water quality and trapping sediment while providing habitat for invertebrates and fish, and food for waterbirds. Beginning in late spring and continuing over the summer, excessive filamentous algal growth in the Coorong negatively impacts on Ruppia growth and seed production throughout the system, particularly in the southern Coorong, with flow-on effects for the Coorong ecosystem (Collier et al. 2017). These impacts are exacerbating the long-term recovery of the Coorong ecosystem following the large-scale losses of the Ruppia community in the Coorong throughout the Millennium Drought despite successful translocation efforts (Collier et al. 2017). The current state of the previously robust Ruppia community, has been described as being in a vulnerable state requiring significant effort to restore resilience and multiple ecological functions (Brookes et al. 2018). Field observations over the last 4-5 years suggest that the southern Coorong has remained in the Hypersalinity–High Nutrient state (Figure 1 – upper right panel).

Figure 1. Conceptual diagram summarising alternative states for the southern Coorong based on observed ecological conditions (from Collier et al. 2017).

The dominance of filamentous algae impacts ecological functions of the southern Coorong through:

Key Knowledge Gaps and Management Questions

The primary focus for this Aquatic Plant and Algae Component is to support management of the Coorong to shift the system from algae-dominated to a Ruppia-dominated habitat, improve water quality and restore the ecological function associated with an aquatic plant dominated state.

The Component will support the management of the Coorong by investigating how to:

To achieve this, a series of more specific questions are being addressed in this research including:

Approach to addressing key knowledge gaps and management questions

Seven Activities are being delivered by the Aquatic Plants and Algae Component (Figure 2)

Figure 2: Conceptual diagram of the Aquatic Plants and Algae Component tasks. Item 7.2 is an activity of the HCHB Integration Component (Component 7) being delivered by DEW.

Literature cited

Brookes, J., Dalby, P., Dittmann, S., O’Connor, J., Paton, D., Quin, R., Rogers, D., Waycott, M., and Ye, Q. (2018). Recommended actions for restoring the ecological character of the South Lagoon of the Coorong. Goyder Institute for Water Research Technical Report Series No. 18/04, Adelaide, South Australia. ISSN: 1839- 2725.

Collier, C., van Dijk, K.-J., Erftemeijer, P., Foster, N., Hipsey, M., O'Loughlin, E., Ticli, K., Waycott, M., 2017, Optimising Coorong Ruppia habitat: Strategies to improve habitat conditions for Ruppia tuberosa in the Coorong (South Australia) based on literature review, manipulative experiments and predictive modelling. Report to Department of Environment and Natural Resources (DEWNR). The University of Adelaide, School of Biological Sciences, Adelaide, South Australia, p. 169 pp.

Dittmann, S, Jessup-Case, H, lam Gordillo, O, and Baring, R (2017). Benthic macroinvertebrates survey 2016-17: Coorong and Murray Mouth Icon Site. Report for the Department of Environment, water and Natural Resources, and the Murray-Darling Basin Authority.

Paton, DC, Paton, FL and Bailey, CP (2017). Monitoring of Ruppia tuberosa in the southern Coorong, summer 2016-17. (University of Adelaide, Adelaide).

Paton, DC, Paton, FL, and Bailey, CP (2018). Condition monitoring of the Lower Lakes, Murray Mouth and Coorong Icon Site: Waterbirds in the Coorong and Lower Lakes 2018. The University of Adelaide and The Department of Environment, Water and Natural Resources (DEWNR).