Table 4. Comparison of metatranscriptomic profiles from manually processed and ESP-collected and preserved samples.

DS compareda		NCBI-nr taxab			WI c	NCBI-nr referencesd			Sig. diff. Refse	% hits in sig. diff. refsf
DS 1	DS 2	DS1	DS2	Both		DS1	DS2	Total		DS1	DS2
SC Vac	SC ESP	785	666	448	0.89	10 723	9386	17 284	6	1.2%	1.1%
M1 PP	M1 ESP	1280	1613	1028	0.82	13 754	25 211	35 036	28	1.6%	1.3%

Abbreviations: ESP, Environmental Sample Processor; nr, non-redundant.

^aData sets used in pairwise comparisons (SC Vac and ESP: Santa Cruz wharf, vacuum-filtered and flash frozen sample and ESP-processed and preserved sample, stored on board ESP for a 30-day deployment in Monterey Bay; M1 PP and ESP: Monterey Bay water collected by rosette sampler, filtered immediately by peristaltic pump or processed and preserved by ESP. Additional pairwise comparisons are listed in Supplementaary Table S2.

^bNumber of taxa (NCBI-nr taxonomy ID's) with one or more uniquely assigned sequences (reads with exactly one top-scoring database match).

^cWhittaker's index of association (Whittaker 1952) for NCBI-nr taxon counts.

^dNumber of NCBI-nr reference genes with one or more mapped reads.

^eNCBI-nr reference genes with significantly different abundances in the two data sets.

^fPercentage of sequences with NCBI-nr hits that map to reference genes with significantly different abundances.