Genetic Biodiversity in Marine Ecosystems

Stellwagen Bank National Marine Sanctuary (SBNMS, https://stellwagen.noaa.gov/) is a historic fishing ground renowned for remarkable productivity with biodiversity conservation being a key management priority. Given that SBNMS resides in the Gulf of Maine where sea surface temperatures are rising faster than 99% of the global ocean, it is critical to establish baseline biodiversity data on the communities living there so that they can be monitored moving forward, especially as the climate continues to change.

In a recent expedition, GMGI sampled sediment at three sites within the Sanctuary over two seasons to provide much needed data on the microbial diversity at the SBNMS¹. DNA was extracted from the sediment samples and specific genes were targeted to provide estimates of diversity for prokaryotes and eukaryotes. The samples contained high diversity at all taxonomic levels and identified 127 phyla, including 115 not previously represented in the SBNMS Management Plan and Environmental Assessment. The levels of biodiversity seen on this small spatial scale provide a baseline for future studies to assess changes in community structure in response to rapid warming in the Gulf of Maine.

Another fascinating marine ecosystem that is closer to home for GMGI is the Annisquam River, which represents a dynamic and variable environment. The Annisquam River experiences large fluctuations in salinity, moisture, temperature, and human activities in response to tidal cycles and seasonal changes throughout a day and over the course of a year. GMGI is assessing the biodiversity of intertidal microbial communities in the Annisquam River on a seasonal basis by sampling sediment of varying depths at five sites along its length. Both DNA and RNA are extracted from the sediment samples to characterize the entire microbial community in the intertidal sedimentary environment. The genetic biodiversity data produced from this study will enhance our understanding of the microbial communities present in the Annisquam River and provide a baseline for any further studies regarding the biological impacts of the variety of anthropogenic activities and environmental stressors that occur there on a regular basis.

1. Polinski, J.M., Bucci, J.P., Gasser, M. and Bodnar, A.G. (2019) Metabarcoding assessment of prokaryotic and eukaryotic taxa in sediments from Stellwagen Bank National Marine Sanctuary. Sci Rep 914820 doi:10.1038/s41598-019-51341-3 https://www.nature.com/articles/s41598-019-51341-3