a1 Key Laboratory for Biodiversity Science and Ecological Engineering, Beijing Normal University, Beijing 100875, China and Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands.
a2 Room 2511, Building 1, 2 Nan-Fang-Zhuang, Fengtai District, Beijing 100079, China.
a3 School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
a4 Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands and Department of Marine Ecology, Royal Netherlands Institute for Sea Research (NIOZ), P.O. Box 59, 1790 AB Den Burg, Texel, The Netherlands.
a5 Key Laboratory for Biodiversity Science and Ecological Engineering, Beijing Normal University, Beijing 100875, China.
a6 International Crane Foundation, Baraboo, Wisconsin 53913, USA.
a7 Key Laboratory for Biodiversity Science and Ecological Engineering, Beijing Normal University, Beijing 100875, China.
The coast of Bohai Bay, north-western Yellow Sea, is critical for waterbirds migrating along the East Asia-Australasian Flyway. Between 1994 and 2010, a total of 450 km2 of offshore area, including 218 km2 of intertidal flats (one third of the original tidal area in the bay), has been reclaimed along the bay for two industrial projects. This has caused the northward migrants to become concentrated in an ever smaller remaining area, our core study site. The spring peak numbers of two Red Knot subspecies in the East Asia-Australasian Flyway, Calidris canutus piersmai and C. c. rogersi, in this so far little affected area increased from 13% in 2007 to 62% in 2010 of the global populations; the spring peak numbers of Curlew Sandpiper C. ferruginea increased from 3% in 2007 to 23% in 2010 of the flyway population. The decline in the extent of intertidal mudflats also affected Relict Gulls Larus relictus, listed by IUCN as ‘Vulnerable’; during normal winters 56% of the global population moved from the wintering habitats that were removed in Tianjin to the relatively intact areas around Tangshan. Densities of wintering Eurasian Curlew Numenius arquata, and spring-staging Broad-billed Sandpiper Limicola falcinellus and Sanderling Calidris alba have also increased in the remaining areas. With the proposed continuation of land reclamation in Bohai Bay, we predict waterbird densities in the remaining areas to increase to a point of collapse. To evaluate the future of these fragile, shared international resources, it is vital to promote an immediate conservation action plan for the remaining coastal wetlands in this region, and continued population monitoring to determine the effects of this action.
(Received July 17 2010)
(Accepted February 22 2011)
(Online publication May 18 2011)