Mud crab indicators for the Gladstone Harbour Report Card: Project ISP015-2019

Mud crabs (Scylla serrata) are recreationally and commercially important species in Gladstone Harbour, as well as an iconic seafood item, with cultural value to Indigenous Australians. In 2017, CQUniversity proposed four mud crab measures for the Gladstone Harbour Report Card: • Abundance • Prevalence of rust lesions • Sex ratio • Biomass In 2019, mud crab monitoring was conducted in seven Gladstone Harbour zones for the third consecutive year, over two sampling events in February and June. Scores and grades were calculated using both data sets for three measures: Abundance, Prevalence of rust lesions, and Sex ratio for each of the seven recommended long-term monitoring zones in Gladstone Harbour. The three measure scores were averaged to reach a Mud Crab Indicator score and grade for each zone, and for the Harbour.