UNLABELLED: In aquatic environments, low dissolved oxygen concentrations can result in depressed bivalve defense systems while promoting anaerobic bacterial growth, ultimately leading to increased bivalve mortality rates. Although the relationship between low oxygen availability and bivalve mortality has been previously examined, the mechanisms of mortality remain not well understood, limiting our ability to predict mass mortality events. In this study, the effect of anoxia (<
0.1 mgO SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00227-025-04617-4.