SHRP Sediment Rehabilitation Program

A key goal of the Sydney Harbour Research Program (SHRP) is to develop nature-based solutions to the environmental problems faced by urbanised estuaries around Sydney. One of the most pervasive and long-standing issues is that of pollution. 

Sydney’s history of industrialisation has left a legacy of metal contamination in estuarine sediments, added to decades of unprocessed sewer discharges up to the 1990s and continued discharges of stormwater. Nowadays, estuarine sediments typically contain high concentration of metals, and excess of nutrients and organic pollutants. This can lead to algal blooms and anoxic conditions in estuaries, driving mass mortalities. The SHRP team is investigating nature-based solutions through ‘bioremediation’, a process utilising living organisms, such as oyster reefs and sediment burrowing organisms (‘bioturbators’) like clams and shrimps to clean sediments.

Recently, the SHRP team, in collaboration with the University of New South Wales, the  University of Sydney, and Macquarie University, has been studying the characteristics of sediments around remnant oyster reefs in Port Hacking and Hunter River. The team wants to establish how oysters influence the processing of pollutants in those sediments. And voila! We found that oyster reefs seem to increase the activity of biotubators, potentially facilitating pollutant removal. Our study shows that there is potential for oyster reef restoration to be used as a form of bioremediation.

The next step is to determine whether bioturbators and oysters effectively remove excess nutrients.

Stay tuned for more updates!