Threatened fauna that use blue carbon ecosystems: A review from Australia

Abstract

Amid global biodiversity and climate crises, restoring blue carbon ecosystems (BCEs) like mangroves, tidal marshes, and seagrass may offer multiple biodiversity and climate benefits. However, species-specific information on BCE use remains unconsolidated and often inaccessible to land managers. Here we compile a database and examine broad ecological patterns in the use of BCEs by threatened Australian fauna, including amphibians, birds, fish, invertebrates, mammals and reptiles. The database is presented within an open-access web tool to assist with restoration decisions and monitoring actions. We identified 30 threatened species that depend on BCEs (‘obligates’), and a further 160 threatened species that benefit from the resources BCEs provide (‘facultatives’). Obligate species included the Critically Endangered Orange-bellied parrot (Neophema chrysogaster), and the Endangered Green turtle (Chelonia mydas), Australian sea lion (Neophoca cinerea) and Mangrove ant-blue butterfly (Acrodipsas illidgei). Obligate species displayed many characteristics often associated with higher extinction risk, including smaller home range sizes, diurnal activity and carnivorous diets. Habitat loss and degradation combined threaten 91.7 % of obligate species, with most species (90.9 %) facing these threats within Australia. Significant disparities exist in available information for obligate species, particularly invertebrates, resulting in greater uncertainty around species ranges and level of reliance on BCEs. With habitat loss and degradation driving declines in threatened species, the conservation importance and potential benefit of future blue carbon protection and restoration projects is pronounced. Our findings and web tool aid project planning by facilitating rapid identification of target species, along with species-specific survey methods, population trajectories, and key threats.