Table 2.

Identified “keystone” OTUs in co-abundance networks.

OTU IDa	Familyb	Betweenness	Closeness	Neighborhood Connectivity	Topological Coefficient	Module Membership
268	NAc	0.51	0.71	8	0.36	Brown
179d	Rhodobacteraceae	0.29	0.51	5	0.28	Brown
1070	NA	0.14	0.9	151	0.16	Turquoise
264	Erythrobacteraceae	0.11	0.63	8	0.41	Brown
265	NA	0.08	0.62	8	0.43	Brown
267	NA	0.07	0.6	9	0.45	Brown
1057	NA	0.06	0.85	161	0.17	Turquoise
176	Rhodobacteraceae	0.05	0.38	3	0.47	Brown
91	Alteromonadaceae	0.05	0.49	276	0.3	Blue
126	Rhodobacteraceae	0.05	0.47	10	0.53	Brown
1040	NA	0.04	0.82	165	0.18	Turquoise
1009	NA	0.03	0.81	163	0.18	Turquoise
1066	NA	0.03	0.8	165	0.18	Turquoise
266	NA	0.03	0.56	10	0.51	Brown
1087	NA	0.02	0.79	168	0.18	Turquoise
1048	NA	0.02	0.8	167	0.18	Turquoise
131	Rhodobacteraceae	0.02	0.52	10	0.5	Brown
257	NA	0.02	0.55	10	0.54	Brown
89	Alteromonadaceae	0.02	0.48	643	0.7	Yellow
92	Alteromonadaceae	0.02	0.33	11	0.44	Yellow

^aAssigned OTU identity.

^bOTU taxonomy at family level.

^cNA, OTU taxonomic assignment not available at family level.

^dProposed “keystone” OTUs Rhodobacteraceae and Alteromonadaceae are highlighted in bold.