Assessing the Potential Distribution of Eriocheir sinensis Under Climate Change: Regional Contrasts and Spatial Mismatches in Terrestrial and Nearshore Suitability

Abstract

ABSTRACT The Chinese mitten crab ( Eriocheir sinensis ), native to China and the Korean Peninsula, has established invasive populations with substantial ecological and economic impacts in Europe and North America. Anticipating changes in its potential distribution is important for invasion‐risk screening and estuarine management. We developed a global species distribution model (G‐SDM) and regional models for the native range, Europe, and North America, each comprising terrestrial and nearshore brackish‐water components. Future suitability was projected under SSP126, SSP245, and SSP585. Terrestrial PCA‐env analyses assessed changes in projected suitable environmental space, whereas MESS and MoD diagnosed environmental novelty and extrapolation uncertainty. Terrestrial suitability was mainly associated with annual mean temperature, annual precipitation, and distance to the coastline, whereas nearshore suitability was mainly associated with water depth, chlorophyll concentration, and sea‐surface temperature, although the ranking of predictor importance differed among regions. Predicted‐suitable environments in Europe and North America extended to lower annual and wettest‐quarter temperatures than those in the native range. Under future scenarios, projected suitability was generally redistributed towards higher latitudes, particularly under SSP585. Terrestrial suitability showed more pronounced spatial redistribution than nearshore suitability in several regions, and the two components were not always geographically aligned. Terrestrial PCA‐env analyses indicated greater retention of suitable environmental space in Europe but increasing unfilling in the native range and North America. MESS analysis further identified environmental novelty and extrapolation uncertainty in some future suitable areas. These findings provide a scientific basis for early prevention, targeted monitoring, field validation, and estuarine management.