Comparative studies of the Connecting ChannelHeavy metals in aquatic macrophytes drifting in a large river B. A. Manny1, S. J. Nichols1 and D. W. Schloesser1 | (1) | National Fisheries Research Center-Great Lakes, U.S. Fish and Wildlife Service, 48105 Ann Arbor, MI, USA |
Abstract Macrophytes
drifting throughout the water column in the Detroit River were
collected monthly from May to October 1985 to estimate the quantities
of heavy metals being transported to Lake Erie by the plants. Most
macrophytes (80–92% by weight) drifted at the water surface. Live
submersed macrophytes made up the bulk of each sample. The most widely
distributed submersed macrophyte in the river, American wildcelery ( Vallisneria americana),
occurred most frequently in the drift. A total of 151 tonnes (ash-free
dry weight) of macrophytes drifted out of the Detroit River from May to
October. The drift was greatest (37 tonnes) in May. Concentrations of
heavy metals were significantly higher in macrophytes drifting in the
river than in those growing elsewhere in unpolluted waters. Annually, a
maximum of 2 796 kg (eight heavy metals combined) were transported into
Lake Erie by drifting macrophytes. The enrichment of all metals was
remarkably high (range: 4 000 × to 161 000 × ) in macrophytes, relative
to their concentration in water of the Detroit River. Detroit River
macrophytes are thus a source of contaminated food for animals in the
river and in Lake Erie. Key words vascular
plants - cadmium - nickel - copper - zinc - lead - Detroit
River - Lake Erie Contribution
734 of the National Fisheries Research Center-Great Lakes, U.S. Fish
and Wildlife Service, 1451 Green Road, Ann Arbor, MI 48105.
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