Fragilaria tenera

This taxon has been reported with light micrographs from northern Québec and Labrador (Fallu et al. 2000), the Canadian Arctic Archipelago (Antoniades et al. 2008), the Great Lakes (Reavie and Kireta 2015), the Rocky Mountains, Great Plains and Cascades (Bahls 2021).

In the Great Lakes National Parks (Edlund et al. 2009, 2011, 2012, 2013), this taxon is common (5-25% abundance) in sediment core material from Pictured Rocks (Grand Sable Lake) and uncommon (1-5% abundance) at Voyageurs (Cruiser Lake).

This is an alpine/northern taxon (Antoniades et al. 2008) reported to occur in a wide variety of habitats with cool alkaline waters of moderate conductivity and nutrient content (Bahls 2021). This taxon is reported to be a very weak indicator of moderate stress (Reavie and Kireta 2015). Cells may form small colonies, joined by linking spines. This taxon is a common member of the plankton.

Many research groups consider this taxon an indicator organism and published regional environmental optima and tolerances including:

Fallu et al. (2000): Dissolved Organic Carbon (DOC) - 7.72 +/- 1.34 mg/L for populations from northern Québec.

Antoniades et al. (2008): pH - 8.0, Tolerance Range - 7.6-8.4, Conductivity - 81 µS/cm, Tolerance Range - 79-133 µS/cm, DOC - 7.31 mg/L, Tolerance Range - 4.91-10.88 µS/cm for populations from the Canadian Arctic Archipelago.

Reavie and Kireta (2015): Report this taxon to have a Total Phosphorus (TP) optima between 10 and 30 µg/L, a Chlorine optima of approximately 10 µg/L, for populations in the Great Lakes.

Bahls (2021): Conductivity - 517 µS/cm, pH - 7.7, Temperature - 17.1°C, Total Nitrogen - 0.53 mg/L, TP - 24 µg/L for populations from Northwestern North America.