Geographe Bay is highly valued by the local community and visitors to the area due to its high ecological, recreational and social values. The sheltered waters of the Bay provide a range of recreational opportunities including safe boating, fishing, swimming, whale watching and many other water based pursuits. The marine and coastal environments of Geographe Bay are a valuable State tourist asset estimated at $300 million per year.
Geographe Bay supports an extensive array of marine fauna – ranging from the large and charismatic humpback whales to highly diverse and unusual species of sponges. The sheltered north facing embayment and the influence of the Leeuwin Current enables a combination of tropical and temperate fauna species to occur in the Bay. These high ecological values were recognised with the inclusion of Geographe Bay in the Ngari Capes Marine Park.
Geographe Bay also supports the most extensive seagrass meadows in temperate Western Australia that provide vital habitat for more than 70 species of fish and other marine life. The seagrass meadows support 10 different species of seagrass, some of which are found at unusually great depths of up to 45m. The seagrass meadows play a vital role in stabilising sediments within the Bay, utilising nutrients in the water column and store more than $83 million worth of carbon.
Without management intervention, nutrient loads flowing into Geographe Bay are predicted to increase through agricultural intensification and urbanisation, putting seagrass meadows at risk.
Seagrass are sensitive to high levels of nutrients that enhance the growth algae which grow on or in the water column above seagrass, reducing light necessary for growth. Large areas of seagrass have been lost from other marine embayment and estuaries in Western Australia as a result of nutrient enrichment.
Maintaining water quality of Geographe Bay to support its high values is a priority of Revitalising Geographe Waterways and will be achieved by actions to reduce nutrients off the catchment. Any actions undertaken in the catchment to reduce nutrients and improve water quality will help protect Geographe Bay.
To keep an eye on seagrasses of Geographe Bay, GeoCatch have been coordinating the “Keep Watch seagrass monitoring” program since 2012. The annual monitoring, carried out by Edith Cowan University and the Department of Biodiversity, Conservation and Attractions keeps a keeps watch of Geographe Bay seagrass meadows by monitoring seagrass health over time.