100. 0 f Viruses|g Viruses|s Sulfitobacter phage pCB2047 C f Viruses|g Viruses|s Sulfitobacter phage pCB2047 A f Sinobacteraceae|g Sinobacteraceae f Vibrionaceae|g Vibrio|s Vibrio splendidus f Vibrionaceae|g Vibrio|s Vibrio kanaloae f Piscirickettsiaceae|g Methylophaga|s Methylophaga 90.0 f Piscirickettsiaceae|g Cycloclasticus|s Cycloclasticus pugetii f Pseudomonadaceae|g Pseudomonas|s Pseudomonas stutzeri f Pseudomonadaceae|g Pseudomonas|s Pseudomonas sp S9 f Pseudomonadaceae|g Pseudomonas|s Pseudomonas pelagia f Pseudomonadaceae|g Pseudomonas|s Pseudomonas f Pseudomonadaceae|g Cellvibrio|s Cellvibrio 80.0 f Moraxellaceae|g Psychrobacter|s Psychrobacter cryohalolentis f Moraxellaceae|g Acinetobacter|s Acinetobacter f Oceanospirillaceae|g Marinomonas|s Marinomonas sp MWYL1 f Oceanospirillaceae|g Marinomonas|s Marinomonas f Halomonadaceae|g Halomonas|s Halomonas titanicae 70.0 f Halomonadaceae|g Halomonas|s Halomonas f Alcanivoracaceae|g Alcanivorax|s Alcanivorax f Gammaproteobacteria|g Gammaproteobacteria|s gammaproteobacterium HIMB55 f Enterobacteriaceae|g Buchnera|s Buchnera aphidicola f Shewanellaceae|g Shewanella|s Shewanella frigidimarina f Shewanellaceae|g Shewanella|s Shewanella baltica 60.0 f Shewanellaceae|g Shewanella|s Shewanella f Pseudoalteromonadaceae|g Pseudoalteromonas|s Pseudoalteromonas undina f Pseudoalteromonadaceae|g Pseudoalteromonas|s Pseudoalteromonas haloplanktis f Pseudoalteromonadaceae|g Pseudoalteromonas|s Pseudoalteromonas arctica f Pseudoalteromonadaceae|g Pseudoalteromonas|s Pseudoalteromonas agarivorans 50.0 f Pseudoalteromonadaceae|g Pseudoalteromonadaceae f Colwelliaceae|g Colwellia|s Colwellia psychrerythraea f Colwelliaceae|g Colwellia|s Colwellia piezophila f Colwelliaceae|g Colwellia|s Colwellia f Alteromonadales|g Alteromonadales|s Alteromonadales bacterium TW 7 f Alteromonadaceae|g Microbulbifer|s Microbulbifer 40.0 f Alteromonadaceae|g Marinobacter|s Marinobacter manganoxydans f Alteromonadaceae|g Marinobacter|s Marinobacter algicola f Alteromonadaceae|g Marinobacter|s Marinobacter f Alteromonadaceae|g Glaciecola|s Glaciecola psychrophila f Alteromonadaceae|g Alteromonas|s Alteromonas f Nautiliaceae|g Nautiliaceae 30.0 f Helicobacteraceae|g Sulfurimonas|s Sulfurimonas f Campylobacteraceae|g Arcobacter|s Arcobacter f Bacteriovoracaceae|g Bacteriovorax|s Bacteriovorax f Gallionellaceae|g Gallionellaceae f Rhodospirillaceae|g Rhodospirillum|s Rhodospirillum 20.0 f Rhodobacteraceae|g Sulfitobacter|s Sulfitobacter sp EE 36 f Rhodobacteraceae|g Sulfitobacter|s Sulfitobacter f Rhodobacteraceae|g Rhodobacteraceae|s Rhodobacteraceae f Rhodobacteraceae|g Oceanibulbus|s Oceanibulbus indolifex f Hyphomonadaceae|g Maricaulis|s Maricaulis maris f Rhodobiaceae|g Rhodobiaceae 10.0 f Bartonellaceae|g Bartonella|s Bartonella f Aurantimonadaceae|g Aurantimonas|s Aurantimonas manganoxydans f Aurantimonadaceae|g Aurantimonadaceae f Sphingobacteriaceae|g Pedobacter|s Pedobacter f Flavobacteriaceae|g Riemerella|s Riemerella 0. 0 f Flavobacteriaceae|g Myroides|s Myroides f Flavobacteriaceae|g Gillisia|s Gillisia 4 8 12 14 4 8 12 14 4 8 12 14 4 8 12 14 4 8 12 14 4 8 12 14 4 8 12 14 4 8 12 14 f Flavobacteriaceae|g Dokdonia|s Dokdonia donghaensis Pre DSW Control DSW Oil DSW Dispersant DSW Dispersed Oil Pre SSW Control SSW O il SSW Dispersant SSW Dispersed Oil f Flavobacteriaceae|g Cellulophaga|s Cellulophaga f Thaumarchaeota|g Thaumarchaeota|s MG I thaumarchaeote SCGC AB 629 I23 Supplementary Figure S2. Taxonomic composition in individual microcosm treatments across a 14-week experiment. Pre-treat represents composition in source water prior to onset of treatment effects. Taxa representing greater than 1% of the total experiment population are displayed.