Impacts of dreissenid mussel growth and activity on phytoplankton and nutrients in Lake Erie's western basin

Authors

  • G.S. Carter Cooperative Institute for Great Lakes Research, University of Michigan, 4840 South State Road, Ann Arbor, MI 48108
  • C.M. Godwin Cooperative Institute for Great Lakes Research, University of Michigan, 4840 South State Road, Ann Arbor, MI 48108
  • T.J. Johengen Cooperative Institute for Great Lakes Research, University of Michigan, 4840 South State Road, Ann Arbor, MI 48108
  • H.A. Vanderploeg National Oceanic and Atmospheric Administration Great Lakes Environmental Research Laboratory, 4840 S. State Rd., Ann Arbor, MI, USA
  • A.K. Elgin National Oceanic and Atmospheric Administration Great Lakes Environmental Research Laboratory, Lake Michigan Field Station, 1431 Beach St., Muskegon, MI, USA
  • P.W. Glyshaw National Oceanic and Atmospheric Administration Great Lakes Environmental Research Laboratory, 4840 S. State Rd., Ann Arbor, MI, USA
  • H.J. Carrick Department of Biology & Institute for Great Lakes Research, Central Michigan University, Mount Pleasant Michigan, USA
  • N. Dahal Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
  • V.J. Denef Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
  • D.L. Fanslow National Oceanic and Atmospheric Administration Great Lakes Environmental Research Laboratory, 4840 S. State Rd., Ann Arbor, MI, USA
  • A.M. Burtner National Oceanic and Atmospheric Administration Great Lakes Environmental Research Laboratory, 4840 S. State Rd., Ann Arbor, MI, USA
  • A.C. Camilleri Cooperative Institute for Great Lakes Research, University of Michigan, 4840 South State Road, Ann Arbor, MI 48108

Keywords:

assimilation rate, clearance rate, Quagga Mussel, Dreissena, growth:assimilation

Abstract

To examine the potential impact of invasive dreissenid mussels on in situ populations of phytoplankton and nutrients in western Lake Erie, we combined mussel population estimates from a 2018 survey, results from mussel excretion, grazing, and in situ growth experiments, along with nutrient measurements on collected lake water. We calculated the proportion of the water column filtered per day, based on both clearance rates from grazing experiments and mussel biomass. In most cases the water column was filtered less than once per day. Based on mussel densities from nearby survey sites, we found that mussels could be expected to clear less than 5% of phytoplankton from the water column each day. We combined measurements of nitrogen and phosphorus excretion by mussels with survey densities and found that concentrations of nitrogen and phosphorus from excretion were much less than the ambient inorganic nitrogen and phosphorus measured throughout the season. Despite the modest potential impact that we measured, spatial variability in mussel density and temporal variability in nutrients and seston suggest that more substantial impact likely occurs in some conditions. Lastly, we used a mass balance approach to compare flows of nitrogen and phosphorus attributable to mussel assimilation, growth, and excretion. The proportion of assimilated nitrogen (0.01-0.21) and phosphorus (0.007-0.08) due to growth changed markedly throughout the season, but the excretion rate sometimes exceeded the apparent assimilation rate. These differences in growth:assimilation suggest changes in food quantity or quality, fluctuations in growth rates over time, or other physiological effects can lead to short-term imbalance in nutrient cycling by mussels, which could lead to locally important impacts on phytoplankton and algal blooms. Moreover, this work underscores the importance of mapping mussel densities at fine spatial scales and across interannual variation.

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Published

2023-10-01

Issue

Vol. 26 No. 4 (2023): Ecology of Lake Erie (Part 1): Nutrients, microbes, algae, and dreissenid mussels

Section

Research article

License

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