Dynamic eutrophication and summer algal blooms do not suppress mussel production: Evidence of system resilience from a Yangtze River-influenced coastal ecosystem

Coastal eutrophication is widely presumed to threaten filter-feeding bivalve aquaculture by inducing algal blooms, yet this relationship rarely follows a simple linear negative feedback in hydrodynamically complex areas. Based on multi-source data (2019–2022) from the Shengs Archipelago—a typical estuary–shelf system in East Asia—we investigated cascading effects of dynamic eutrophication on mussel yield. Results show that pulsed terrestrial inputs reshaped a “low-phosphorus, high nutrient stoichiometric ratio” habitat window, triggering summer blooms characterized by diatom–dinoflagellate alternation. Notably, the study area did not follow the traditional eutrophication–production decline trajectory; instead, unit-area mussel yield increased steadily from 124.97 to 153.17 t·ha −1 over the study period, without clear evidence of basal ecosystem degradation. Bivalve aquaculture responses to eutrophication are thus highly context-dependent. Sustained production may reflect combined effects of nutrient structure optimization, functional group restructuring, management improvements, and system resilience, although direct causality requires further investigation.