ASSESSMENT OF SEDIMENT QUALITY IN DREDGED AND UNDREDGED AREAS OF THE TRENTON CHANNEL OF THE DETROIT RIVER, MICHIGAN USA, USING THE SEDIMENTQUALITY TRIAD
Jm. Besser et al., ASSESSMENT OF SEDIMENT QUALITY IN DREDGED AND UNDREDGED AREAS OF THE TRENTON CHANNEL OF THE DETROIT RIVER, MICHIGAN USA, USING THE SEDIMENTQUALITY TRIAD, Journal of Great Lakes research, 22(3), 1996, pp. 683-696
The ''sediment quality triad'' approach was used to assess the effects
of dredging on the sediment quality of a new marina in the Trenton Ch
annel of the Detroit River, and to evaluate spatial and temporal varia
tion in sediment quality in the Trenton Channel. Samples were collecte
d in November of 1993 (10 months after dredging) and characterized by
chemical analysis, sediment bioassays, and assessment of benthic inver
tebrate communities. The three study components indicated little diffe
rence in sediment quality at dredged sires in the marina relative to n
earby areas in the Trenton Channel, and little change in sediment qual
ity of Trenton Channel sites relative to conditions reported in the mi
d-1980s. These results suggest that improvement in sediment quality in
the Trenton Channel, due to dredging or natural processes, will depen
d on elimination of sediment ''hot spots'' and other upstream contamin
ant sources. Concentrations of chemical contaminants, especially metal
s and polycyclic aromatic hydrocarbons, exceeded concentrations associ
ated with effects on biota and were significantly correlated with resu
lts of sediment bioassays and characteristics of benthic communities.
Laboratory sediment bioassays with Hyalella azteca and Chironomus tent
ans produced better discrimination among sites with differing degrees
of contamination than did characterization of benthic communities, whi
ch were dominated by oligochaetes at all sites in the marina and the T
renton Channel.