WRRC/‘Ike Wai Seminar

Phylogenetic Diversity of Groundwater Microbes in Hawai‘i Reveals Aquifer Characteristics

by Dr. Sheree Watson

Interconnectivity in groundwater aquifers of the volcanic Hawaiian Islands is poorly understood, difficult to study, and increasingly vulnerable to anthropogenic disruptions. Although geochemical and geophysical research provides some knowledge about these complex groundwater aquifers, there has been little to show how microbial community structures can aid and reveal the hydrogeochemistry of aquifers. Based on phylogenetic diversity analysis of other terrestrial subsurface ecosystems, we formulated a hypothesis that isolated aquifers would create a distinct biogeography of microbes in groundwater. In this study, we investigated groundwater bacteria and archaea communities in the Hualālai watershed in Kona, Hawai‘i. The objectives of our study were to (1) discover how connected the high level and basal aquifers were in the watershed, and (2) how the volcanic rift zone dividing the watershed affected the groundwater flow or connectivity between the aquifers. We applied comparative microbial phylogenetic analysis to determine the connectivity, infer the direction of the subsurface flow, and map the potential sources of anthropogenic contamination. Methodology included sampling drinking water wells in the watershed, and performing 16S rRNA microbial diversity analysis to determine the relationships between microbial community diversity and groundwater hydrology.

Event Sponsor
WRRC, Mānoa Campus

More Information
Niels Grobbe, (808) 956-5857, ngrobbe@hawaii.edu

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