The IUCN Species Survival Commission and IUCN Asia Regional Office commissioned this independent report to assess the state and condition of intertidal habitats along the East Asian- Australasian Flyway (EAAF), in response to growing concerns expressed by IUCN members over observed declines in biodiversity, the loss of ecological services, and an increase in ecological disasters. This report is a situation analysis, and it seeks to gather in one place the relevant data and analyses, and to present as clear a picture of the status of the intertidal zone in the EAAF as the data allow. By intention, this report makes no recommendations, but it should serve as a resource for those stakeholders empowered to make or influence decisions and policies in the region. This report makes use of the status and population trends of key species of waterbirds as indicators of the environmental health of intertidal habitats (including beaches, marshes, mudflats, mangroves and seagrass beds). It presents an analysis of 395 coastal sites used by waterbirds along the EAAF and identifies 16 key areas. The findings presented show that there is cause for significant concern over the status of the intertidal zone along the EAAF. Fisheries and vital ecological services are collapsing and ecological disasters increasing, with concomitant implications for human livelihoods. Observed rates of declines of waterbird species of 5–9% per year (and up to 26% per year for Critically Endangered Spoon-billed Sandpiper Eurynorhynchus pygmeus) are among the highest of any ecological system on the planet. Breeding success among migrating species in their Arctic breeding grounds and survival on most wintering grounds (for northern breeding species) at the southern end of their migrations appears satisfactory, at least where hunting is sustainable. However, problems clearly are occurring along the EAAF during migration. Unless major steps are taken to reverse current trends, the EAAF is likely to experience extinctions and associated collapses of essential and valuable ecological services in the near future. Although all sectors of the EAAF face a variety of threats, the Yellow Sea (including the Bohai Sea) emerges as the focus of greatest concern, with six of 16 key areas identified in this report in the region. Here, the fast pace of coastal land reclamation is the most pressing threat. Remote sensing and geographical information system (GIS) analyses show losses of up to 60% of intertidal habitats in some key areas. In total, more than 41% of the existing tidal flat area was reclaimed within the six key areas identified by this study. Losses of such magnitude are likely the key drivers of declines in biodiversity and ecosystem services in the intertidal zone of the region. This report reviews the drivers that are leading to such environmental degradation. We evaluated the processes that should maintain or restore a balance between developmental needs and environmental needs (including legal instruments, financing, habitat and species conservation, awareness and knowledge), and found that these were usually weak, and were in some cases dysfunctional. Drivers are reviewed at both the national and site-specific level. The report highlights the risks to biodiversity, to the livelihoods of coastal communities, and to economic investments if the ‘business as usual’ scenario continues. The stakes are very high including loss to fisheries sector valued at US$ billions per year and the potential loss of US$ trillions of coastal cities, towns and lands. The countries along the EAAF have made commitments to global biodiversity targets under several key multilateral environmental agreements, but it will not be possible for the countries to meet these commitments without halting the declining trends in species populations and habitat availability and quality identified in this report. Each country’s economic and environmental sustainability is beingdamaged by the actions of its neighbours. Various existing regional seas initiatives are failing to address these specific problems. The fast pace and nature of human developments affecting the EAAF jeopardizes species that depend on this zone as well as the valuable ecological services that intertidal zone ecosystems deliver to humans. Different species use different suites of sites during northbound and southbound migrations. Therefore, protection of only the best sites will not provide an adequate site network for all migratory species and broader protection of a comprehensive and complementary set of sites is necessary. Although this is a situation analysis and does not include recommendations, we allow ourselves this comment. The birds and habitats of the EAAF are the shared natural heritage of 22 countries. Many of the steps that need to be taken to secure this resource in the long term will require international cooperation. Unless the fast economic development of this region can be balanced with adequate environmental safeguards, impressive-looking economic gains could be short-lived and undermined by the loss of valuable ecosystem services and a growing list of costly ecological disasters.