A study finds that a single invasive species may largely control phosphorus cycling in four of the Great Lakes. The ecology of the Great Lakes has been altered by the invasion of quagga and zebra mussels, with primary production declining by up to 70% following their introduction. However, the role of the mussels in the cycling of phosphorus, the productivity-limiting nutrient in the Great Lakes for which inputs have been regulated, is not well known. Jiying Li, Sergei Katsev, and colleagues developed a mass balance model to evaluate the impact of the invasive mussels on the phosphorus cycle. As filter feeders on the lake floor, the mussels are able to ingest large quantities of particulate phosphorus from the water and redistribute it through physiological processes and decomposition. The authors found that a single species, the invasive quagga mussel, may now be the primary regulator of phosphorus cycling in the lower four Great Lakes, owing to their large biomass. The authors also found that the sensitivity of the geochemistry of the Great Lakes to changes in mussel population is increased and sensitivity to external nutrient load management is decreased. According to the authors, the results forewarn about the possibility of similar ecological changes in lakes across Europe and North America that have been invaded by quagga and zebra mussels.
Article #20-08223: "Benthic invaders control the phosphorus cycle in the world's largest freshwater ecosystem," by Jiying Li et al.
MEDIA CONTACT: Sergei Katsev, University of Minnesota, Duluth, MN; tel: 218-269-4624; email: skatsev@d.umn.edu
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Proceedings of the National Academy of Sciences