Science for restoring and enhancing estuary values – Vasse Wonnerup

Report from the National Estuaries Network Science Forum on Barrier Estuaries

The Department of Water, Water Science Branch and Busselton office together with Geocatch, hosted the National Estuaries Network Science Forum on Barrier Estuaries with special focus on the Vasse Wonnerup System (VWWS) – a wetland of international significance (Ramsar, 1990).

Around 60 estuary managers, researchers and interested community members met in Busselton to exchange information about the Vasse Strategy, science needs for estuary management and the current state of the VWWS. 

Opening comments highlighted that aligned and collaborative sciences, supported by robust baseline level data are essential for effective decision-making.

Implementing the Vasse Strategy includes a restructure of governance arrangements, development of a business case to fund the strategy, reviewing the drainage infrastructure and continued catchment management interventions.

The history of flow and drainage modifications designed to protect Busselton from flooding were also shown to have contributed to the eutrophic conditions in the lower rivers and estuaries.

Advances in hydrological modelling and smarter engineering solutions are being investigated to achieve essential flood protection as well as better water quality by increased dilution of lowland river flows, helping to reduce nutrient concentrations and the undesirable expression of nuisance algal blooms and fish kills.

Early stage research projects, part of the South West Catchment Council Research Node for the Vasse Wonnerup Wetlands will explore quantitative food web structure, nutrient sources and sinks and socio-economic factors.

The connection with and potential impacts on the receiving water body – Geographe Bay were also explored.  Geographe Bay has one of the largest seagrass meadows on the WA coast. A nation-wide risk assessment for seagrass meadows indicated that climate-driven temperature increase poses the greatest threat to South West seagrass integrity and that this is a greater threat than estuarine water nutrient discharge to Geographe Bay due to the drying climate pattern.

The feedback from members of the National Estuaries Network was that all of the elements needed for successful restoration appear to be in place but the integrated and thoughtful synthesis of all actions, progress and estuary health status updates would greatly assist communication between all stakeholders and sustain the momentum of support that has emerged.

Community interest is high, there has been 18 years of GeoCatch activity in catchment restoration and some highly visible media campaigns for behaviour change such as “Save the Crabs and Eat Them”.  Community members appreciated the opportunity to engage with estuary managers and researchers.

Vasse Wonnerup System and adjacent Geographe Bay are incredible natural assets; with the strong community interest, there are opportunities to greatly enhance eco-tourism activities around this wetland benefiting the economy, society and environment.

We thank all the people who participated in this event. The Abstract booklet includes the speakers and their contact information.

National Estuaries Science Forum on Barrier Estuaries (Busselton)