Table 2.

Richness and diversity statistics for nirS clone libraries from five Chesapeake Bay sediment samples.

Station	No. of clones	No. of OTUs	Unique OTUs*	ACE†	Chao1†	Shannon	Simpson's
CT1	100	51	44	97	95	3.69	0.02
CT2	111	35	25	126	88	2.98	0.07
CB1	123	59	45	139	116	3.54	0.05
CB2	96	30	18	82	57	2.75	0.10
CB3	120	23	17	80	46	1.79	0.35
Combined	550	172		468	360	4.24	0.04

^†ACE and Chao1 are non-parametric estimators which predict the total number of OTUs in the original sample.

^*OTUs detected in only 1 of the 5 Chesapeake Bay sediment samples.