Stable isotope analyses reveal anthropogenically driven spatial and trophic changes to Indo-Pacific humpback dolphins in the Pearl River Estuary, China.

摘要: As long-lived apex predators in the Pearl River Estuary (PRE) of China, Indo-Pacific humpback dolphins (Sousa chinensis) are particularly vulnerable to anthropogenic impact and may undergo considerable ecological trait changes. The variability traits, however, is often difficult trace back nature. Here, we analyzed stable isotope ratios carbon nitrogen muscle samples 88 S. chinensis stranded PRE from 2004 2016 investigate changes occurring dolphins. Stable analysis revealed existence two sub-aggregations PRE. Generalized additive models showed significant decreasing trends both isotopic signatures over time, indicating habitat dietary shifts, possibly due influence increased coastal developments fishing activities Diet modeling suggests that proportional contribution higher trophic-level prey decreased diet while consumption lower was observed. This shift related depletion caused by overfishing. Although could temporarily compensate for lost energy supply through feeding plasticity (revealed negligible differences niche width among different stranding periods), long-term availability cause long-lasting negative effects on this dolphin population. study highlights crucial relationships between fishery management conservation, providing scientific evidence protection threatened species region.