Abstract: The coastal zone around Bohai Sea is rich in wetland resources, which are important habitat and resting place for many waterbirds on East Asian-Australian migration routes. Based on the data of waterbird geographical distribution and several environmental variables, the MaxEnt model was used to evaluate the suitability of waterbird habitats, and geographical detectors were used to quantitatively analyze the impacts of natural and social factors on the distribution of waterbirds. The results showed that: (1) The suitable distribution area of waterbirds in the coastal zone around Bohai Sea was mainly concentrated in the boundary water of the coastline. The highly suitable area was mainly concentrated in the central part of the coastal zone around Bohai Sea. Tianjin occupied the largest highly suitable area with an area of 1706.1 km², followed by Tangshan with an area of 1566.15 km²; (2) According to the results of the MaxEnt model, the primary factor driving the suitable habitat distribution of waterbirds in the coastal zone around Bohai Sea was vegetation type, followed by soil type and normalized difference vegetation index. The results of the geographical detectors showed that the main driving factor limiting the distribution of waterbirds was vegetation type. In addition, soil type, land use type, and normalized difference vegetation index were also important driving factors affecting the distribution of waterbirds, which were basically consistent with the results of the MaxEnt model. From the interaction of various factors, the interaction type of most factors was nonlinear enhancement, and the interaction type of a small number of factors was double-factor enhancement. Among them, the interaction between nighttime lighting and vegetation type was the strongest, followed by that between vegetation type and normalized difference vegetation index. By identifying the key habitats of waterbirds in the coastal zone around Bohai Sea, our results provide a scientific basis for the protection, restoration, and management of waterbirds and their habitats in this region.

Key words: coastal zone around Bohai Sea, MaxEnt model, geographical detector, habitat suitability evaluation