Eunotia bilunaris

Eunotia bilunaris has wide geographic and habitat distribution in North America. It has been reported from epiphytic and epilithic site of the Great Smoky Mountains (Furey et al. 2011), wetlands (Burge 2014), lakes (Antoniades et al. 2008, Siver and Hamilton), and in rivers of Québec-Labrador (Fallu et al. 2000).

Antoniades et al. (2008) observed E. bilunaris in less than 2% abundance occurring benthic in small lakes and ponds of Prince Patrick Island (Northwest Territories, Canada), with the following water chemistry: pH 7.1-8.0, conductivity 40-97 µS/cm, and 4.79-10.34 DOC (mg/L). Siver and Hamilton (2011) observed E. bilunaris occurring in ponds and canals of the Pocosin NWR (North Carolina), with a pH 4.5+/-1.2 and TP 37+/-18 µg/L. Burge (2014) observed E. bilunaris populations occurring <1% to 48% relative abundance in assemblages with E. formica, E. metamonodon, E. praeruptua, as well as species of Gomphonema, Navicula, and Pinnularia, in cypress-tupelo wetlands of the Cache River NWR (Arkansas) with the following water chemistry: 19.2–31.5oC, pH 5.18 –7.7, DO 0.1–7.7 mg/L, specific conductance 11.8–1358 µS/cm, Turbidity 3.9–628 NTU, Chlorophyll-a 0–167.3mg/L, NH3-N 0.1–16.1, NO3-N <0.1–0.8 mg/L, NO2-N 0–0.2 mg/L, TN 0.6–8.1 mg/L, TP <0.1–4.6 mg/L, and PO4-P <0.1–2.8 mg/L.

In Europe, E. bilunaris is found within moderately dystrophic waters with increased concentrations of sulfate (Alles et al. 1991).