Table 1. OTUs whose abundance exceeded 20% in the samples.

Protist main taxa	Identification at genus rank	Environment of highest abundance	Highest abundance (%)
Ciliophora	Paramecium	Freshwater	0.96
Ciliophora	Laurentiella	Freshwater	0.80
Ciliophora	Frontonia	Freshwater	0.65
Ciliophora	Blepharisma	Freshwater	0.53
Ciliophora	Zoothamnium	Brackish	0.48
Labyrinthulomycetes	Labyrinthula	Freshwater	0.46
Diatomea	Synedra	Freshwater	0.44
Dinoflagellata	Blixaea	Brackish	0.42
Phragmoplastophyta	Spirogyra	Freshwater	0.41
Ciliophora	Heliophrya	Freshwater	0.40
Diatomea	Amphora	Brackish	0.31
Diatomea	Pleurosigma	Brackish	0.27
Ciliophora	Prorodon	Freshwater	0.27
Diatomea	Gyrosigma	Brackish	0.25
Diatomea	Stenopterobia	Freshwater	0.22