Metagenomics to characterize sediment microbial biodiversity associated with fishing exposure within the Stellwagen Bank National Marine Sanctuary.

Microbes in marine sediments constitute a large percentage of the global marine ecosystem and function to maintain a healthy food web. In continental shelf habitats such as the Gulf of Maine (GoM), relatively little is known of the microbial community abundance, biodiversity, and natural product potential. This report is the first to provide a time-series assessment (2017-2020) of the sediment microbial structure in areas open and closed to fishing within the Stellwagen Bank National Marine Sanctuary (SBNMS). A whole metagenome sequencing (WMS) approach was used to characterize the sediment microbial community. Taxonomic abundance was calculated across seven geographic sites with 14 individual sediment samples collected during the summer and fall seasons. Bioinformatics analyses identified more than 5900 different species across multiple years. Non-metric multidimensional scaling methods and generalized linear models demonstrated that species richness was inversely associated with fishing exposure levels and varied by year. Additionally, the discovery of 12 unique biosynthetic gene clusters (BGCs) collected across sites confirmed the potential for medically relevant natural product discovery in the SBNMS. This study provides a practical assessment of how fishing exposure and temporal trends may affect microbial community structure in a coastal marine sanctuary.