Using cumulative human impact assessment to support adaptive management of the threatened species’ habitats in the Yangtze River Estuary

Abstract

The conflict between multiple functions of human use and habitat conservation represents an intractable challenge for environmental management. While numerous studies on marine conservation prioritize cumulative impact assessments (CIA) to tackle this issue, estuaries — despite their immense conservation significance amidst intense human activities — remain overlooked. Taking the Yangtze River Estuary (YRE) as the case study area, it is one of the most intensely human-utilized estuaries globally, yet it serves as a critical habitat and migratory corridor for the endangered Chinese sturgeon (Acipenser sinensis).We employed ecological indicators and quantitative modeling to assess habitat suitability and cumulative anthropogenic impacts on this endangered species in the YRE. The results demonstrated that suitable habitat distribution and human impact varied for juvenile Chinese sturgeon in the YRE. The suitable habitat distribution for juvenile Chinese sturgeon was concentrated in Chongming Dongtan and the North Channel. Ship density, submarine optical cables, and smooth cord grass invasion were the main anthropogenic factors impacting the Chinese sturgeon's migrating habitat in the YRE. Moreover, existing Chinese sturgeon habitats remain at risk, with 36.24 % of potential habitats and 56.60 % of high human impact areas requiring enhanced protection. Adaptive management strategies were proposed, tailored to the spatial and environmental protection needs across the dynamic habitat demands of aquatic species. Our spatially explicit and indicator-based findings provide key scientific support for enlarging protected areas and implementing adaptive management of human activities to balance conservation and sustainable use in this highly utilized ecosystem.