Molybdenum and sulfate as controls on the abundance of nitrogen‐fixing cyanobacteria in saline lakes in Alberta

• DOI: 10.4319/lo.1990.35.2.0245
• Publication Date: 2010-04-10T02:32:20Z
• Authors: Roxanne Marino; Robert W. Howarth; Jennifer Shamess; Ellie Prepas
• Keywords: 13. Climate action; 14. Life underwater; 15. Life on land; 01 natural sciences; 6. Clean water; 0105 earth and related environmental sciences

We studied 13 saline lakes in Alberta to test the hypothesis that molybdenum availability influences abundance of planktonic, N‐fixing cyanobacteria ecosystems. Our earlier work oxic seawater showed Mo is controlled part by ratio sulfate because inhibits assimilation molybdate. The SO 4 2− : very high relative most freshwater lakes—a finding consistent with scarcity coastal marine This constant seawater, however, limiting a our systems. These salt provide more robust within any given lake was relatively over summer season, but between varied and ranged from values typical higher than seawater. are significant fractions plankton six we rare or absent others. strong predictor cyanobacteria. Sulfate concentrations alone, were not. can control waters. Phosphorus concentrations, N P, not good predictors these lakes, as they often lakes. differences predictions freshwater, P regression model actual abundances best explained ratio.