Arabic version: جهود الاستعادة تنعش نظام نهر سوان البيئي

Efforts to restore shellfish reefs in the Swan River have significantly improved the river’s health and marine life. According to ABC News, the project, initiated by The Nature Conservancy, aims to bring back lost marine habitats that were historically abundant in the area.

Historically, the river, known as Derbal-Yerrigan to the Noongar people, was rich in shellfish reefs that provided essential habitats for various marine species. However, from the 1920s to the 1950s, about 1 million tonnes of limestone that formed shellfish reefs was pulled out of the Swan River bed, leading to severe degradation of the ecosystem. The loss of these reefs resulted in soft sediments accumulating, which increased nutrient loads and contributed to declining water quality.

In 2023, The Nature Conservancy began constructing artificial reefs using limestone to restore the river’s natural habitat. The project has successfully established about 6 hectares of reef in areas previously dominated by soft sediment. Additionally, 160 tonnes of mussels were grown in Cockburn Sound and later translocated onto the reefs in November 2022 to help jumpstart the ecosystem.

The restoration efforts have already shown positive outcomes, with shellfish populations, including mussels, oysters, and scallops, thriving on the new reefs. Furthermore, fish stocks have improved, with various species beginning to use the reefs as habitat, enhancing the river’s ecological balance.

Monitoring will continue through the Department of Biodiversity, Conservation and Attractions, while The Nature Conservancy plans to focus on restoring the health of shallower river areas. New pilot reef structures have been installed close to the shoreline to combat erosion and protect local habitats, supporting both the ecosystem and community recreation.