Temporal and Spatial Trends in Benthic Infauna and Potential Drivers, in a Highly Tidal Estuary in Atlantic Canada

Abstract Infaunal invertebrate communities of coastal marine sediments are often impacted by human activities, particularly in harbours and estuaries. However, while many studies have attempted to identify the key factors affecting benthic infauna, few done so for highly energetic tidal Samples were collected over a decade (2011–2020) from series reference sites Saint John Harbour (45.25° N, 66.05° W), estuary Bay Fundy, Canada. These data used examine spatial temporal trends infaunal sediment properties determine extent which biological patterns driven measured physical chemical variables. There substantial differences among abundance (median ranging 688 13,700 individuals per square meter), species richness 8 22), Shannon diversity 1.26 2.34); multivariate analysis also revealed variation composition sites. Sediment contaminant concentrations varied sites, but tended be smaller (e.g. median chromium 21.6 27.6 mg/kg). Sample all below probable effect levels, almost threshold levels (Canadian interim quality guidelines), relationships with still detectable. variables (depth, characteristics) better predictors community composition. results confirm importance shaping soft-sediment habitats tidally influenced waters.