Overview of the most abundant taxa (≥ 1% relative abundance in at least one sample). 35 Fistulifera saprophila 36 Craticula subminuscula 37 Craticula sp. 2 38 Craticula molestiformis 39Craticula cf. pumilio40 Sellaphora cosmopolitana 41 Sellaphora sp. 3 42 Eolimna sp. 1 43 Sellaphora nigri 44 Sellaphora madida 45 Sellaphora queretana 46 Sellaphora atomoides 47 Sellaphora saugerresii 48 Sellaphora pupula 49 Mayamaea permitis 50 Reimeria sinuata 51 Diadesmis confervacea 52 Nupela wellneri 53 Geissleria decussis 54 Navicula veneta 55 Navicula erifuga 56 Navicula libonensis 57 Navicula capitatoradiata 58 Navicula symmetrica 59 Navicula notha 60Navicula cf. cryptocephala61Encyonopsis cf. thienemannii62 Navicula gregaria 63 Navicula cryptocephala 64 Navicula reichardtiana 65 Brachysira altepetlensis 66 Encyonema minutum 67 Halamphora montana 68 Amphora pediculus 69 Navicula trivialis 70 Navicula rostellata 71 Frustulia crassinervia 72 Encyonema brevicapitatum 73 Encyonema minutiforme 74Encyonema cf. minutiforme75Encyonema cf. hebridiforme76 Encyonema jemtlandicum 77 Encyonema pergracile. Scale bar 10 μm.