Presenter: Rae Santora (University of Southern California)

Description:
Documented patterns of spatial variability in microbial community structure have historically been based on samples from widely dispersed sites. Therefore, little is known about the variability of microbial communities over fine spatial scales which is necessary for the extrapolation of specific samples to larger oceanographic regimes. To assess the spatial variability of microbial communities with finer resolution, surface seawater samples were collected from the Florida Strait over the course of 3 days in 2018. We analyzed the microbial communities of the free-living size fractions through 16S and 18S rRNA tag sequencing using the Parada universal primers (515F-926R). Bray-Curtis distances between sites suggest that the prokaryotic community (average similarity = 0.73) is much more consistent over the entire cruises transect compared to the eukaryotic and chloroplast communities (average BC similarities = 0.06 and 0.32, respectively). Future analyses will explore which taxa are driving the prokaryotic stability and the eukaryotic variability.