Spatial and temporal distribution patterns and conservation status of seagrasses in the Yellow Sea and Bohai Sea

Seagrasses represent a significant class of marine foundation species, yet the distribution of seagrasses in the Yellow Sea and Bohai Sea remains uncertain, thereby impeding the efficacy of conservation and restoration practices. In this study, the spatial and temporal distribution pattern of seagrasses was simulated by the MaxEnt model based on the construction of marine environment and human activity datasets. The main controlling factors affecting seagrass potential distribution were analyzed, and the response of seagrass distribution to global change was clarified. Additionally, the current status of protected and disturbed seagrass meadows was determined. The results indicate the accuracy of the MaxEnt model was enhanced (AUC = 0.987) through the integration of a human activity index, pinpointing a highly suitable seagrass area of 867.64 km². The primary factors dictating seagrass distribution were identified as human activities index (18.4 %), water quality indicators (including nitrate 20.9 %, silicate 11.3 %, and dissolved iron 6.4 %), and topographic elements (such as bathymetry 15.1 % and slope 12.0 %). The highly suitable areas for seagrasses showed a gradual expansion in the future, with a projected increase of 12 % in 2100 under the SSP585 scenario. A binary overlay analysis showed that only 2.61 % of seagrass potential habitats (highly and moderately suitable areas) were adequately protected, highlighting a significant conservation gap in the Yellow Sea and Bohai Sea regions. On the contrary, seagrass potential habitats exposed to mariculture activities were as much as 49.76 %. These findings underscore the urgent need for monitoring and protecting seagrasses in the study area, with the establishment of MPAs emerging as a viable conservation strategy. This research provides a scientific basis for understanding the degradation and conservation status of seagrass meadows and has important practical implications for targeted conservation and restoration efforts of these critical marine foundation species.