Factors influencing the growth of Mougeotia in experimentally acidified mesocosms

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Acidification causes profound changes in species composition in aquatic systems. We conducted mesocosm experiments in three northern Wisconsin lakes (Trout Lake, Little Rock - Reference, Little Rock - Treatment) to test how different phytoplankton communities respond to acidification. Major differences exist among these lakes in water chemistry and phytoplankton community composition. In each lake, three pH treatments (control, press (sustained pH 4.7), and pulse (alternating pH 4.7 and ambient pH)) were maintained for 6 weeks. We observed a striking increase in species in the genus Mougeotia in all systems. Mougeotia is a filamentous green alga often found in acidified lakes. The magnitude of the Mougeotia increase differed among lakes and treatments, and we used an autoregressive model to identify potential factors responsible for these differences. Our results suggest that biotic factors such as competition with other algae played a relatively minor role in regulating Mougeotia dynamics. Instead, pH and abiotic factors associated with changes in pH (e.g., dissolved inorganic carbon) were important predictors of Mougeotia dynamics.


Copyright 2000 NRC (National Research Council) Canada

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Canadian Journal of Fisheries and Aquatic Sciences

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Klug, J. L., & Fischer, J. M. (2000). Factors influencing the growth of Mougeotia in experimentally acidified mesocosms. Canadian Journal of Fisheries and Aquatic Sciences, 57(3), 538-547. doi: 10.1139/f99-274.



Peer Reviewed