Functional diversity of zooplankton communities in two tropical estuaries (NE Brazil) with different degrees of human-induced disturbance

•Copepoda functional diversity in two Northeast Brazilian estuaries was assessed.•Two different trait-based approaches applied: functional groups and FD indices.•Comparable FD between estuaries with different anthropogenic intensities.•Environmental filter as the main driver of species coexistence.

This study assessed the functional diversity (FD) of copepod communities along the environmental gradient of two tropical estuaries with different intensities of human impact - the environmentally protected “Mamanguape” and the urbanised “Paraiba”. Different trait-based approaches were used: functional groups identification and description, and FD indices estimation.The results showed similar functional groups and functional indices between the two estuaries with some variability attributed to seasonality. Copepods in each estuary seemed to perform similar functions. Overall, biomass was more evenly distributed among groups, and mean total biomass and FD indices were slightly higher in the Mamanguape. Nevertheless, both estuaries presented comparable FD, indicating that environmental filters may be the main driver of species coexistence within systems. Results also pointed towards anthropogenic disturbance, despite the protection status of the Mamanguape.