Science Serving Maryland's Coasts

Aleszu Bajak, Amherst College

Class Year: 

Project Title: 

Community Composition of Bacteria Associated with Zostera marina Within and Across Beds in the Chesapeake Bay


Bacterial community composition was surveyed across three separate species and sites. Leaf and root samples from each bed per species were collected and bacterial community composition was characterized by denaturing gradient gel electrophoresis of PCR-amplified 16S ribosomal DNA. Multidimensional scaling analysis revealed the dense canopy-forming Stuckenia pectinata and Potamogeton perfoliatus to have very similar leaf bacterial communities, between 86 and 90% degree similarity, whereas Zostera marina demonstrated much more variability within and across its beds. Differences in seasonality, salinity and plant structure affected bacterial community composition. Across species, bacterial community populations on Z. marina tended to be less similar on its leaves and roots than those on the roots and leaves of S. pectinata or P. perfoliatus. Bacterial cultures of 96 isolates found some overlap in community but no substantial matching, proving cultivation to be more difficult than anticipated for restoration purposes.