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Johengen, T.H., T.F. Nalepa, G.L. Fahnenstiel, and G. Goudy, 1995. Nutrient Changes
in Saginaw Bay, Lake Huron, After the Establishment of the Zebra Mussel (Dreissena
polymorpha), Cooperative Institute for Limnology and Ecosystems Research -
University of Michigan, NOAA/Great Lakes Environmental Research Laboratory, Lake Michigan
Field Station, Michigan Department of Natural Resources
Reprinted from J. of Great Lakes Res. 21(4): 449-464, International Association
of Great Lakes Research, 1995.
Nutrient Changes in Saginaw Bay, Lake Huron, After the
Establishment of the Zebra Mussel (Dreissena polymorpha)
Abstract
Concentrations of particulate and dissolved nutrients in Saginaw Bay, Lake Huron, were
examined relative to zebra mussel colonization which occurred summer 1991. The magnitude
and spatial pattern of changes indicate that mussels had a significant impact on nutrients
in Saginaw Bay. Annual means for total suspended solids, particulate organic carbon,
particulate phosphorus, and particulate silica in the inner bay were significantly lower
in 1992 and 1993 (post-zebra mussel) than in 1991 pre-zebra mussel). Annual means
decreased from 11.5 mg L-1, 1.45 mg C L-l (121 m M)), 20.4 mg P L-1
(0.66 mM), and 1.52 mg SiO2 L-l (24 mM respectively in 1991 to
4.4 mg L-1, 0.79 mg C L-1 (66mM), 11.2mg P L-1(0.36 mM),
and 0.77 mg SiO2 L-1 (12 mM) in 1993. In contrast, there were no
significant differences among years for these parameters at control stations, which were
located in the outer bay and had no known populations of mussels. Annual means for
nitrate, ammonium, and silica were significantly higher in the inner bay in 1992 than in
1991, but not significantly different in 1993. Means increased from 0.39 mg N L-1,
21.0 m g N L-1, and 1.11 mg SiO2 L-l respectively in 1991
to 0.47 mg N L-l, 30.9 m g NL-t, and 1.71 mg SiO2 L-l in
1992. No significant differences were observed for these parameters in the control group.
Differences between 1992 and 1993 may reflect differences in the amount of runoff and
circulation between Saginaw Bay and Lake Huron.
A phosphorus budget indicated that zebra mussels were a significant sink for
phosphorus. Mussels from the inner bay accumulated 108, 682, and 52 t respectively in
1991, 1992, and 1993. Comparatively, the annual pool of phosphorus in the water column of
the inner bay decreased from a pre-zebra mussel (1979-1980) average of 712 t to 421 and
382 t in 1992 and 1993 respectively.
Entire Paper
Contact: T.H. Johengen, Cooperative Institute for Limnology and Ecosystems
Research, University of Michigan, 2200 Bonisteel Blvd., Ann Arbor, Michigan 48109
Keywords: Zebra_mussel, Environmental_impacts, Basic_biology
Product Type: Research,
Impact
User Type: General
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