Benthic habitat mapping and sediment nutrient fluxes in a shallow coastal environment in Nova Scotia, Canada

Coastal embayments are dynamic open systems characterized by multiple sedimentary environments with specific biogeochemical properties, which instead are influenced by physicochemical and biological processes (e.g., hydrodynamics, carbon deposition, abiotic-chemical reactions, macrofaunal and microbial activity). In this study, a novel approach that combines benthic habitat mapping, empirical measurements, and multivariate analysis was used 1) to determine the variability of benthic primary production, respiration, and denitrification in different sediment types; and 2) to examine how sediment nutrient fluxes are influenced by organic content, porosity, salinity, temperature, depth, light availability, habitat, and sediment type. Of the total observed variance in benthic metabolic activity, 12.6%–66.5% was accounted for by these variables. Results highlight the important role of benthic diversity and their contribution to energy and matter cycling in coastal sediments. Consideration of these factors is key for the prediction of benthic processes at scales relevant for coastal management and valuation of associated ecosystem services.