Offshore and Estuarine Artificial Reefs

Cardno diver monitoring and testing coral underwater

Cardno was engaged by the NSW DPI Fisheries to help with the location selection, constraints mapping, field investigations and approvals for the deployment of large-scale artificial structures in both estuarine and offshore environments.

Artificial reefs are not new. In fact, they have been used for hundreds of years in oceans and seas around the world. Early sailors noticed large numbers of fish inhabiting areas in and around sunken vessels, realising large objects placed in the sea are rapidly colonised by marine life. 

These artificial reefs significantly enhance the underwater habitat and have flow-on economic benefits derived from recreational fishing and diving around them.

Two offshore artificial reefs have been deployed off the south coast of NSW, the first off Sydney and the second in the Shoalhaven. Five estuarine artificial reefs have also been deployed within NSW in Lake Macquarie, Merimbula Lake, Lake Conjola, St Georges Basin and Botany Bay.

Our team have the knowledge and experience of artificial reef ecology to prepare detailed environmental assessments and undertake baseline and monitoring surveys to follow their development.

Key tasks our team completed for the successful deployment and monitoring of the artificial reefs included constraints mapping and site selection using GIS and multi-criteria analysis, ecological field investigations covering fish, water and sediment quality as well as benthos (flora and fauna found on the bottom of a sea or estuary).

We also conducted seafloor acoustic surveys, risk and impact assessments, including threatened species assessment, the development of environmental management plans, artificial reef user guidelines and the successful procurement of sea dumping permits.