Historical Associations of Molecular Measurements of Escherichia coli and Enterococci to Anthropogenic Activities and Climate Variables in Freshwater Sediment Cores.
This study investigated the long-term associations of anthropogenic (sedimentary P, C, and N concentrations, and human population in the watershed), and climatic variables (air temperature, and river discharge) with Escherichia coli uidA and enterococci 23S rRNA concentrations in sediment cores from Anchor Bay (AB) in Lake St. Clair, and near the mouth of the Clinton River (CR), Michigan. Calendar year was estimated from vertical abundances of (137)Cs. The AB and CR cores spanned c.1760-2012 and c.1895-2012, respectively. There were steady state concentrations of enterococci in AB during c.1760-c.1860 and c.1910-c.2003 at ∼0.1 × 10(5) and ∼2.0 × 10(5) cell equivalents (CE) per g-dry wt, respectively. Enterococci concentrations in CR increased toward present day, and ranged from ∼0.03 × 10(5) to 9.9 × 10(5) CE/g-dry wt. The E. coli concentrations in CR and AB increased toward present day, and ranged from 0.14 × 10(7) to 1.7 × 10(7) CE/g-dry wt, and 1.8 × 10(6) to 8.5 × 10(6) CE/g-dry wt, respectively. Enterococci was associated with population and river discharge, while E. coli was associated with population, air temperature, and N and C concentrations (p < 0.05). Sediments retain records of the abundance of fecal indicator bacteria, and offer a way to evaluate responses to increased population, nutrient loading, and environmental policies.
Department of Microbiology and Molecular Genetics, 480 Wilson Road, Room 13, Michigan State University , East Lansing, Michigan 48824, United States.
Yolanda M
YM
Brooks
Center for Water Sciences, Michigan State University, 288 Farm Lane, Room 203, Michigan State University , East Lansing, Michigan 48824 United States.|The Water Institute of the Gulf , 301 North Main Street, Suite 2000, Baton Rouge, Louisiana 70825, United States.
Melissa M
MM
Baustian
Department of Geology, 0224 Old Main, Wayne State University , Detroit, Michigan 48202, United States.
Mark
M
Baskaran
Department of Integrative Biology, 288 Farm Lane, Room 203, Michigan State University , East Lansing, Michigan 48824, United States.
Nathaniel E
NE
Ostrom
Department of Microbiology and Molecular Genetics, 480 Wilson Road, Room 13, Michigan State University , East Lansing, Michigan 48824, United States.|Department of Fisheries and Wildlife, 480 Wilson Rd Rm 13, Michigan State University , East Lansing, Michigan 48824, United States.
Joan B
JB
Rose
D016983:Enterococcus; D004784:Environmental Monitoring; D004926:Escherichia coli / Q000145:classification*; D019015:Geologic Sediments / Q000382:microbiology; D006801:Humans; D045483:Rivers / Q000382:microbiology