Mud crab indicators for the 2021 Gladstone Harbour Report Card

Man holding crab


Report cards are increasingly popular tools communicating the condition of coastal and riverine environments to environmental managers, stakeholders and the public, and synthesising complex data drawn from a range of indicators. Mud crabs have not previously been included in ecosystem health report cards in Australia or elsewhere but have been suggested as environmental indicators for tropical coastal marine environments in Australia. Mud crabs support commercial, recreational and Indigenous fisheries. For these reasons and due to their local relevance, mud crabs (Scylla serrata) were selected for long-term monitoring and inclusion in a report card for Gladstone Harbour, Australia. Three mud crab measures were identified to reflect the variety of pressures across Gladstone Harbour: abundance, prevalence of rust lesions and sex ratio. A standardised field monitoring program was developed to allow for ongoing scoring and reporting of the multi-metric indicator


An indicator scoring (distance from benchmark) and grading methodology was applied to the indicator and refined over the two years of monitoring. This article provides a novel framework for monitoring and scoring mud crabs for management purposes or for use in report cards, and outlines the process of developing an indicator for an iconic crustacean species.


Nicole Flint

Dr Nicole Flint- Project Lead

Dr Nicole Flint is a Research Fellow in the School of Health, Medical and Applied Sciences and leads CMERC’s research in Sustainable Coastal Resources. With postgraduate qualifications in fish biology and economics, and previous work experience in fisheries management, she has worked for CQUniversity since 2011. Her research is primarily focused on improving monitoring, assessment and management of aquatic environments; environmental report cards; and fisheries management. Nicole is also the Postgraduate Research Coordinator for SHMAS, a research member of the CQUniversity Animal Ethics Committee and a member of the Fitzroy Partnership for River Health’s Independent Science Panel.

At CQUniversity we are committed to embedding sustainable practice in our operations, interactions and relationships, underpinned by the United Nations Sustainable Development Goals. Sustainability sits as one of our strategic pillars within our

Strategic Plan 2019-2023.

This project aligns to the following SDG Goals:

  • 4 - Quality education
  • 8 - Decent work and economic growth
  • 17 - Partnerships to achieve the Goal