Establishing indicators for a report card in a complex marine ecosystem

Marine environmental report cards are an increasingly popular tool to communicate scientific results to stakeholders and communities. The challenge in developing a report card for complex marine habitats where changes in abundance, cover, distribution and species can occur is establishing appropriate indicators to evaluate habitat condition. We developed an innovative approach for reporting on the condition of seagrasses as part of a broader report card on the environmental, social, cultural and economic health of one of Australia's largest multi-commodity ports located in the Great Barrier Reef World Heritage Area. The process used expert opinion to determine the best indicators of seagrass condition (above-ground biomass, meadow area, species composition), trialled four approaches to determine a baseline condition of each indicator, and defined five condition categories (very good - very poor) to grade each seagrass meadow relative to a baseline. Threshold levels for each condition category were determined based on the historical variability of each indicator in a meadow. The report card approach allowed for the presentation of a large amount of spatial information, including the location, condition, and the reason for each meadow’s grade to be presented within a single map. This allowed not only for rapid comparison of seagrass condition across the range of meadows within the port, but also at a broader regional scale.