Fig. 1

Map of the study area in Lianyungang and its location in northern Jiangsu Province, China (inset). Letters denote the locations of (a) Linhong Estuary, (b) Qingkou Estuary and (c) Xingzhuang Estuary tidal flats. Most of the coastline is bounded by concrete seawalls, areas immediately on the landward side of the seawall were mostly claimed in 2011. The major type of land use inside the seawall is aquaculture or undeveloped ponds (shown in the darkest blue, mainly rectangle-shaped). A salt pond complex (shown in different shades of blue) and a wastewater basin (shown in the lightest blue) are also present south of Linhong Estuary. Other colours denote dry land. Base image courtesy of Landsat