Coastal and Marine Ecosystems of the Arafura and Timor Seas - Characterization, Key Features and Ecological Significance

The tropical Arafura and Timor Seas (ATS) region lies on the edge of the Coral Triangle, located at the intersection of two major Large Marine Ecosystems, the Northern Australian Shelf and the Indonesian Sea. Under the influence of the Indonesian Through Flow current and Pacific-Indian Ocean exchange, the ATS also lies at a major 'cross-road' of global ocean circulation and climate regulation. The 'semi-enclosed' ATS is characterized by diverse seascapes, pronounced ecological connectivity (marine biodiversity, shared fisheries, land-sea interactions), extensive coastal wetlands and shallow-water ecosystems, and globally-significant marine biodiversity (particularly corals reefs, mangroves, seagrasses, and populations of marine megafauna). Complex oceanography, bathymetry and large-scale, tidal and monsoon-driven circulation, and localized, seasonal upwellings are major features across the region, driving patterns of ocean productivity, reef biodiversity and sustaining rich pelagic ecosystems. With some of the most extensive, productive and near-pristine tropical coastal ecosystems in the world, the waters of the ATS are a global marine biodiversity 'hotspot' and play a crucial role in maintaining regional/global tropical marine biodiversity. Including providing major migration corridors, critical habitats and a regional/global refuge for some of the world's most threatened marine megafauna and wildlife populations (particularly sea turtles, sharks/rays, sawfish/river sharks, whales, dolphins and dugongs). Coastal habitats in the ATS also provide a range of ecosystem services of fundamental importance to human well-being, including climate change; with climate-resilient coral reefs and some of the largest and intact, tropical wetlands (mangroves, saltmarshes, seagrasses) in the world, the ATS region is a recognized global blue carbon hotspot. The characterization and assessment of key ecosystems and processes in the ATS in this study provide the basis for protecting these resources through the Arafura and Timor Seas Ecosystem Action Program.