Peter L Lenaker
Biography
M.S. in Oceanography and Coastal Sciences, Louisiana State University, 2009
B.S. in Environmental Science, Western Washington University - Huxley College of the Environment, 2006
A.A. in Environmental Studies, North Seattle College, 2003
Science and Products
MMSD Watercourse Corridor Study: Contaminants in Water and Sediment
There are many kinds of chemical, physical, and biological contaminants contained in water and sediment, and new or “emerging” contaminants are continually being discovered. USGS investigations of contaminants in the MMSD Watercourse Corridor Study include studies of PAHs, microplastics, wastewater contamination, waterborne pathogens, as well as modeling long term trends in water quality.
Human and Bovine Virus Prevalence in Some Great Lakes Tributaries Influenced by Watershed-Specific and Seasonal Characteristics
Human enteric and bovine-specific viruses were detected in eight Great Lakes tributaries. Presence and concentration of human viruses increased in watersheds with greater than 25 percent urban influence and more than 2,900 people per square kilometer. Similarly, bovine viruses increased in watersheds having greater than 40 percent agricultural land influence and cattle densities greater than...
Spatial distribution of microplastics in surficial benthic sediment of Lake Michigan and Lake Erie
The spatial distribution, concentration, particle size, and polymer compositions of microplastics in Lake Michigan and Lake Erie sediment were investigated. Fibers/lines were the most abundant of the five particle types characterized. Microplastic particles were observed in all samples with mean concentrations for particles greater than 0.355 mm...
Lenaker, Peter L.; Corsi, Steven R.; Mason, Sherri A.Primary sources of polycyclic aromatic hydrocarbons to streambed sediment in Great Lakes tributaries using multiple lines of evidence
Polycyclic aromatic hydrocarbons (PAHs) are among the most widespread and potentially toxic contaminants in Great Lakes (USA/Canada) tributaries. The sources of PAHs are numerous and diverse, and identifying the primary source(s) can be difficult. The present study used multiple lines of evidence to determine the likely sources of PAHs to...
Baldwin, Austin K.; Corsi, Steven R.; Oliver, Samantha; Lenaker, Peter L.; Nott, Michelle A.; Mills, Marc A.; Norris, Gary A.; Paatero, PenttiVertical distribution of microplastics in the water column and surficial sediment from the Milwaukee River basin to Lake Michigan
Microplastic contamination was studied along a freshwater continuum from inland streams to the Milwaukee River estuary to Lake Michigan, and vertically from the water surface, water subsurface and sediment. Microplastics were detected in all 96 water samples and nine sediment samples collected. Results indicated a gradient of polymer presence with...
Lenaker, Peter L.; Baldwin, Austin K.; Corsi, Steven R.; Mason, Sherri A.; Reneau, Paul; Scott, John WHuman-associated indicator bacteria and human-specific viruses in surface water: a spatial assessment with implications on fate and transport
Hydrologic, seasonal, and spatial variability of sewage contamination was studied at six locations within a watershed upstream from water reclamation facility (WRF) effluent to define relative loadings of sewage from different portions of the watershed. Fecal pollution from human sources was spatially quantified by measuring two human-associated...
Lenaker, Peter L.; Corsi, Steven R.; McLellan, Sandra L.; Borchardt, Mark A.; Olds, Hayley T.; Dila, Deborah K.; Spencer, Susan K.; Baldwin, Austin K.Patterns of host-associated fecal indicators driven by hydrology, precipitation, and land use attributes in Great Lakes watersheds
Fecal contamination from sewage and agricultural runoff is a pervasive problem in Great Lakes watersheds. Most work examining fecal pollution loads relies on discrete samples of fecal indicators and modeling land use. In this study, we made empirical measurements of human and ruminant-associated fecal indicator bacteria and combined these with...
Dila, Deborah K.; Corsi, Steven R.; Lenaker, Peter L.; Baldwin, Austin K.; Bootsma, Melinda J.; McLellan, Sandra L.Hydrologic, land cover, and seasonal patterns of waterborne pathogens in Great Lakes tributaries
Great Lakes tributaries are known to deliver waterborne pathogens from a host of sources. To examine the hydrologic, land cover, and seasonal patterns of waterborne pathogens (i.e. protozoa (2), pathogenic bacteria (4) human viruses, (8) and bovine viruses (8)) eight rivers were monitored in the Great Lakes Basin over 29 months from February 2011...
Lenaker, Peter L.; Corsi, Steven R.; Borchardt, Mark A.; Spencer, Susan K.; Baldwin, Austin K.; Lutz, Michelle A.Organic contaminants in Great Lakes tributaries: Prevalence and potential aquatic toxicity
Organic compounds used in agriculture, industry, and households make their way into surface waters through runoff, leaking septic-conveyance systems, regulated and unregulated discharges, and combined sewer overflows, among other sources. Concentrations of these organic waste compounds (OWCs) in some Great Lakes tributaries indicate a high...
Baldwin, Austin K.; Corsi, Steven R.; De Cicco, Laura A.; Lenaker, Peter L.; Lutz, Michelle A.; Sullivan, Daniel J.; Richards, Kevin D.Pre-USGS Publications
Human Bacteria, Viruses from Sewage Found in Some Milwaukee Streams
Two types of human-associated bacteria and three types of human viruses were detected in Milwaukee streams within the Menomonee River watershed, according to a recent study led by the U.S. Geological Survey.
Human, Cattle Viruses Detected in Some Great Lakes Tributaries
Human and bovine, or cattle, viruses were detected in a small percentage of some Great Lakes Basin streams, with human viruses more prevalent in urban streams and bovine viruses more common in streams in agricultural areas, according to a recent U.S. Geological Survey-led study.