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

[Extract] Ruppia tuberosa is the dominant aquatic plant supporting water birds in the Coorong, a wetland of international importance under the Ramsar Convention. Historical changes to the hydrology of the Coorong and the ‘Millennium drought’ led to hypersalinity (>200 g/L) and low water levels that exceeded the tolerance of R. tuberosa. As a result R. tuberosa was not observed in the south lagoon during the drought. The seed banks had become depleted from reduced water levels caused by over extraction and the prolonged drought and when flows from the Murray-Darling Basin led to higher water levels in the Coorong in 2011, Ruppia tuberosa populations were restricted and recovery was slow. Translocation facilitated recovery at some sites; however, elevated water levels in the Coorong saw an increase in the occurrence of filamentous green algae blooms which are interfering with the recovery of R. tuberosa. The Optimising Coorong Ruppia habitat project was formed to 1. synthesise existing Ruppia knowledge; 2. undertake experiments testing filamentous green algae growth requirements; 3. assess the pools of nutrients in the sediments and primary limiting nutrients for plant growth; 4. model management scenarios; and 5. develop management recommendations to optimise the Coorong for R. tuberosa (Figure 1).

N/A

N/A

N/A

N/A

N/A

N/A

168