THE achievements of the largest seagrass rehabilitation project in the world and certainly the most successful in Australia – The Cockburn Sound Seagrass Research and Rehabilitation Plan (SRRP) – have surprised even the WA marine scientists working on the project. While rehabilitation of land in the wake of mining activities is commonplace, the rehabilitation of impacted marine areas is far less advanced and a relatively rare occurrence.

The SRRP, underway in Cockburn Sound (35 km south of Perth), is world leading in terms of the seagrass species being revegetated and the planting techniques being employed.

Nowhere else in the world have such deep and turbulent coastal waters been tackled for a major seagrass rehabilitation program.

The richness of seagrass species in Perth’s coastal waters is the highest in Australia with 13 of the 50 known species of seagrasses found worldwide growing in Perth’s coastal waters.

These seagrasses typically occur in shallow waters, and can be lost due to a number of factors including agricultural and industrial discharges and pollution, marine and shoreline activities as well as dredging and land reclamation.

Areas of the seabed in Owen Anchorage (immediately north of Cockburn Sound) are rich in shell sand, which is dredged by Cockburn Cement Ltd to produce lime for WA’s cement and minerals processing industries.

The development of the Jervoise Bay Southern Harbour for Australian Marine Complex Common User Facility and the Northern Harbour Ship Building precinct, by the Department of Industry and Resources (DoIR), has also required significant dredging and land reclamation in Cockburn Sound.

Stringent environmental management conditions for these projects were placed on the two organisations due the industrial development impacts on seagrass meadows in and adjacent to Cockburn Sound.

So Cockburn Cement and DoIR joined forces to establish and fund the highly successful collaborative SRRP.

WA’s largest specialist marine science consultancy, Oceanica Consulting Pty Ltd, is managing the various research and rehabilitation activities directed at meeting the environmental management condition to: “develop and implement seagrass rehabilitation procedures that are economically feasible and environmentally sustainable”.

The SRRP also involves replanting and regenerating at least 2.1ha of seagrass in Cockburn Sound and 1ha in harbours in the Albany Region.

The overall project team, working in collaboration, includes three WA universities, the Kings Park Botanic Gardens and Parks Management Authority, WA environmental consultants and a WA marine engineering firm.

Work includes research on seagrass growth, ecological function and genetics, as well as large-scale planting.

According to Oceanica’s leading marine scientist Dr. Karen Hillman, results to date indicate that the replanted seagrass meadows will return to full ecological function within 6 to 8 years of planting, which commenced in 2004.

The expected continued success of the Cockburn Sound SRRP will therefore clearly demonstrate for the first time that large scale seagrass rehabilitation, especially in difficult marine environments, is feasible.