Table 2.

Sample identification, lake location, and general characteristics. Some geochemical parameters were determined in duplicate.

Lake ID no.	Pyrosequencing reads	Lake location and sample type	Temp.(C°)	pH	Depth (m)	Selected nutrients and energy sources
						NH4	CO2(aq)	S2−(aq)	O2(aq)	CH4(aq)	H2(aq)
						uM	mM	uM	uM	uM	uM
ELLIOT'S CRATER
1	1672	Elliot's Crater Vent emissions	63–68	6.4	14.1	45.0	0.49,47	21.7	119	2.5, 2.1	762, 558
MARY BAY
2	2186	Vent steamers and sediments	62–82	5.2	50.5	53.8	3.77, 1.80	79.5	bd	28.1, 12.4	2984, 2797
INFLATED PLAIN
3	257	IP photic 10 m 0.1 um filter	12.2	6.1	10	2.6	0.11, 0.11, 0.10	2.5	261	2.4, 2.7, 2.6	773, 798, 716
4	1553	IP photic 10 m 0.8 um filter
5	252	IP photic 10 m 3.0 um filter
6	3221	IP vent steamer 1	40–60	5.2	30	30.9	3.1, 3.2	248	bd++	20.9, 22.5	1031, 1430
7	2510	IP steamer 2
8	2222	IP vent 2 emissions	44–52	5.6	33.6	8.2	1.1, 1.1	98	bd	6.7, 5.4	1974
9	1996	IP mixing zone water	21–30	5.6	33.3	37.5	0.57	118	23	2.7	386
WEST THUMB
10	3309	WT deep vent emissions (2007)	60–66	6.2	52.0	12.1	1.7	2.1	113	6.4	49
11	2797	WT deep vent emissions (2008)	40–73	6.0	52.3	23.4	2.4	11.0	197	7.6	32
12	1959	WT deep vent steamer	40–73	6.0	52.3	23.4	2.4	11.0	197	7.6	32
13	1904	WT deep vent mixing zone water	26	6.6	52.1	27.2	ND*	0.3	211	ND	ND
14	638	West thumb cone vent	37	6.7	26.1	27.4	10.22	bd	82	7.6	14
SOUTHEAST ARM
15	377	SEA photic 10 m 0.1 um filter	12.3	7.0	10.0	6.2	0.02	0.1	273	0.1	33
16	1221	SEA photic 10 m 0.8 um filter
17	412	SEA photic 10 m 3.0 um filter

^*ND, Not determined.

⁺⁺bd, Below detection.