Proximity to built structures on the seabed promotes biofilm development and diversity

Abstract

The rapidly expanding built environment in the northern Gulf of Mexico includes thousands of human built structures (e.g. platforms, shipwrecks) on the seabed. Primary-colonizing microbial biofilms transform structures into artificial reefs capable of supporting biodiversity, yet little is known about formation and recruitment of biofilms. Short-term seafloor experiments containing steel surfaces were placed near six structures, including historic shipwrecks and modern decommissioned energy platforms. Biofilms were analyzed for changes in phylogenetic composition, richness, and diversity relative to proximity to the structures. The biofilm core microbiome was primarily composed of iron-oxidizing Mariprofundus, sulfur-oxidizing Sulfurimonas, and biofilm-forming Rhodobacteraceae. Alpha diversity and richness significantly declined as a function of distance from structures. This study explores how built structures influence marine biofilms and contributes knowledge on how anthropogenic activity impacts microbiomes on the seabed.

Keywords:

• Biofilm
• built environment
• ocean sprawl
• microbiome
• carbon steel
• seabed

Acknowledgements

The authors thank the Captain and Crew of R/V Point Sur, the ROV Odysseus (Pelagic Research Services, Inc.) team, and members of shipboard science parties, including Rachel Moseley, Dr. Justyna Hampel, Anirban Ray, and Jeff Glenny for support during field work. They also thank Anirban Ray for assistance with laboratory analyses of samples and Eric Peterson for assistance with design of the MREs, lander arrays, and the release mechanism used for ROV deployment. The authors are grateful to Dr. Joe Griffitt (USM) and Dr. Jason Lee (NRL) for reviewing the study design and manuscript content prior to submission.

Disclosure statement

The authors declare no conflict of interest.

Data availability statement

The data that support the findings of this study are openly available in the NCBI SRA at https://www.ncbi.nlm.nih.gov/sra/ under BioProject PRJNA902766.

Additional information

Funding

Funding was provided by the Defense Advanced Research Projects Agency (DARPA) Biological Technologies Office under Cooperative Agreement D18AC00018, and by the National Oceanic and Atmospheric Administration’s (NOAA) Office of Ocean Exploration and Research Program under Cooperative Agreement NA18OAR0110286.