Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Rarefaction curves displaying observed OTU richness versus the number of nirS clones sequenced from each of five Chesapeake Bay sediment samples. OTUs were defined according to 5% nucleotide sequence difference using the furthest neighbor method.
