Core and abundant OTUs found in the Porphyra umbilicalis microbiome identified using V8 (Taxonomic level 2 = phylum, 3 = class, 4 = order, 5 = family, 6 = genus).

a13 OTUs (0.03 distance) found across fall, winter & lab groups.*present at≥1% of all sequences on at least one blade (n = 12)*L≥1% on a lab blade**present at ≥1% on all 12 bladesbOTUs (0.03 distance) with sequence abundance greater than 1% on both lab bladescOTUs (0.03 distance) with sequence abundance greater than 1% on at least 3 of the 10 winter (n = 5) and fall (n = 5) blades; underlined OTUs present on at least 5 of 10 blades; OTU 2521 present on all.Designations of F = Fall, E = Evenly distributed between fall and winter, W = Winter refer to a ≥3× skew in sequence abundance toward that group.