Figure 5.
Histogram of the eight most common OTUs from the five Chesapeake Bay nirS clone libraries. OTUs were considered common if the total abundance of an OTU was ≥2% of the total number of nirS clones analyzed (550). The x-axis lists the OTU designation (8 of 172 OTUs are displayed), as well as the percentage of total sequences that each OTU comprises.