This report is one in a series of eco-narrative documents that synthesise our existing knowledge of Australia’s individual Marine Parks. This series is a product of the National Environmental Science Program Marine Biodiversity Hub Project D1, which seeks to collate, synthesise and visualise biophysical data within the parks. These documents are intended to enable managers and practitioners to rapidly ascertain the ecological characteristics of each park, and to highlight knowledge gaps for future research focus.
Geographe Marine Park contains areas of high biodiversity and benthic productivity, although much of the Marine Park has not been surveyed. The Park contains some of the largest continuous seagrass meadows in Australia. These act as feeding, breeding, resting and nursery grounds for migratory and threatened seabirds, whales and numerous fish species. Because seagrass communities are particularly susceptible to changes in water quality, they are under constant threat from a range of potential stressors. These include an increase in human population on the adjacent coastline, high levels of regional nutrient flow from runoff, growth in tourism, recreational and commercial fishing, introduced marine pests, and global climate change. While our existing knowledge of these threats is insufficient to detect the full extent of current impacts or to predict future ones, an overall loss in the shallow water seagrass cover from 2004 and 2007 has occurred. The information in this eco-narrative collates all the existing information to form an initial characterisation of Geographe Marine Park to help better understand its ecosystem structure. However, most of our knowledge of ecosystems in the marine park are those based on seagrass. We know very little about other ecosystems, particularly deeper offshore habitats which represent approximately 50% of the marine park.