MTM 1: The sandy beach microbiome: physical, chemical and biological controls on diversity and function

Sandy beaches represent a large fraction of the world’s unfrozen shoreline and they are under serious threat from sea level rise. They provide important ecosystem services including water filtration and nutrient cycling. These processes are controlled by a community of microorganisms working together called a microbiome in the beach subsurface.

While we know the importance of microbiome activity in these systems, there are limited studies that characterize the microbial community in this environment. The goal of this project is to characterize the microbiome in the beach subsurface and investigate the environmental factors that control its structure and function. This goal will be achieved using next generation sequencing methods that provide vast amounts of genetic information from DNA and RNA sequences.

Successful completion of this project will advance knowledge and understanding across different scientific fields including environmental microbiology, ecology, and environmental engineering and science. The proposed work will benefit society by furthering the understanding of the ecosystem services provided by beaches, information critical to understanding the impact of sea level rise on the environment.

The diversity of the Nation’s STEM workforce will be increased by engaging college students from diverse backgrounds in the research. Further benefits to society will result from teaming with elementary school teachers to create learning modules on bacteria for school-aged children. The research team will also conduct outreach to the public during field work to educate them about the beach ecosystem and engage government officials on the issue of sea level rise.

The steep spatial physicochemical gradients and large temporal variation make the subterranean estuary of sandy beaches an ideal study system to focus on the goal of identifying the rules governing microbiome structure and function in coastal environments. This will be achieved by i) characterizing the microbiome in the subterranean estuary, ii) investigating the mechanisms controlling sandy beach microbiome dynamics, and iii) assessing microbial immigration via transport through the sands and local adaptation to changes in porewater chemistry.

The research will employ state-of-the-science amplicon sequencing, metagenomics, and metatranscriptomics together with methods from hydrology and biogeochemistry. The research benefits society by furthering the understanding of the ecosystem services provided by beaches in terms of biogeochemical cycling. As beaches are threatened by sea level rise, this work is essential to fully anticipate the effects of sea level rise on the planet.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.