Moreton Bay sits to the east of Brisbane, Australia’s third largest city. The bay contains a mosaic of coastal habitats that have been affected by poor water quality from the mainland, from which four large and several small river estuaries drain from a highly developed catchments. The Brisbane River is the largest river discharging into Moreton Bay and typically contains nutrient and sediment levels well above local and national water quality guidelines levels. The majority of flow from the Brisbane River runs north from the mouth into the western side of the bay which has led to the loss of seagrass meadows in Deception Bay and Bramble Bay. Until recently, seagrass in Moreton Bay has been steadily declining, causing increasing concern. Seagrasses form the basis of critical habitats in coastal environments globally, providing essential services that support the ecological and biodiversity or marine ecosystems and the lifestyles and livelihoods of coastal communities.
In 2020, EcoFutures staff partnered with Science Under Sail Australia to map the extent, condition and biodiversity of seagrass meadows in Moreton Bay for Healthy Land and Water, the Natural Resource Management organisation for southeast Queensland. The project was unique in that it used citizen scientists, supervised by experienced researchers to conduct field work in the bay. Our staff ran multiple field trips with volunteers, mapping seagrass at nearly 7,000 sites across the bay. We also deployed baited underwater cameras to quantify the biodiversity of fish species that use the seagrass meadows in the bay.
Our mapping showed a continuation of the recovery of seagrass meadows in southern Deception Bay that has been tracked by the project since 2009 and in Bramble Bay since 2017. It also showed that the Bay’s seagrass meadows are home to a much greater diversity of fish species than adjacent unvegetated areas. The work will be used by the Natural Resource and Marine Park managers for ongoing policy and strategy setting.