On August 25, Hurricane Harvey made landfall on San Jose Island, TX as a category 4 storm. During the subsequent five days, precipitation reached over 130 cm of rain onto the Houston area, causing city-wide flooding. The floodwaters/runoff inundation introduced large amounts of terrestrial and freshwater microbes and anthropogenic pollutants into Galveston Bay and ultimately the Gulf of Mexico, causing disruptions to the resident communities. Microbes, composed of viruses, bacteria, and protists, are tightly inter-connected and are constantly adjusting to their environment to maintain a critical balance in global biogeochemical cycles. The main objective of this project is to characterize the effect of Hurricane Harvey on microbial communities in Galveston Bay, with a focus on determining the role of viruses in the ecosystem recovery. This project will determine the effect of Hurricane Harvey and subsequent flooding in the Houston area on microbial communities, measure the impact of viral lysis on the ecosystem to determine the role of viruses in the recovery of the ecosystem after heavy mixing and flooding caused by a major storm, and identify the role of viruses in the adaptation of their hosts in the acquisition of new metabolic capabilities. The approach is to integrate metagenomic characterization of viral and bacterial host diversity over time with water quality measurements. Virus-induced microbial mortality will also be calculated to measure the impact of viral lysis on the ecosystem, while prophage induction will be used to identify the role of viruses in the adaptation of their hosts.
This research will provide significant insight on how viruses play an important role in the adaptation and resilience to environmental changes and stresses. Consequences of climate change include stronger and more frequent tropical storms and hurricanes, with worsening droughts but higher precipitation. Subtropical climates such as the one in Galveston Bay are already feeling the consequences of climate change and it is becoming clearer that there is a need to understand how microbial communities are impacted by environmental perturbations. Collectively microbes in these environmental zones have the greatest influence on biogeochemical cycles; and thus, are also those likely to be under greatest pressure to respond to changes. This project will provide direct quantification of the impact of viral lysis after an extreme weather event towards a better understanding of their role in the adaptation of microbial communities to changes. This study will help to develop an understanding of the evolution and adaptation of microbial communities over time to environmental stresses and how the confluence of weather events creates pressures on microbial community dynamics.