Karen L. Knee
Stanford University
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Publication
Featured researches published by Karen L. Knee.
Marine Pollution Bulletin | 2010
Karen L. Knee; Richard W. Gossett; Alexandria B. Boehm; Adina Paytan
Caffeine has been associated with wastewater pollution in temperate and subtropical locations, but environmental caffeine concentrations in tropical locations have not been reported. The objectives of this study were to measure caffeine and agricultural pesticide (carbaryl, metalaxyl, and metribuzin) concentrations in environmental waters on the tropical north shore of Kauai (Hawaii, USA) and assess whether patterns in caffeine concentration were consistent with a wastewater caffeine source. Groundwater, river, stream and coastal ocean samples were collected in August 2006 and February 2007. Caffeine was detected in all August 2006 samples and in 33% of February 2007 samples at concentrations up to 88ngL(-1). Metribuzin was detected in five samples collected in February 2007. Carbaryl and metalaxyl were not detected in any sample. Caffeine was not detected in offshore ocean samples or river samples upstream of human development. A positive correlation between caffeine and enterococci suggested a possible wastewater caffeine source.
Human and Ecological Risk Assessment | 2018
Emil Bayramov; Karen L. Knee; Martin Kada; Manfred F. Buchroithner
ABSTRACT This research focused on the following objectives: (1) using satellite data to characterize the spatiotemporal distribution of anthropogenic oil spills from Oil Rocks Settlement, Chilov and Pirallahi Islands (2) stochastic modeling of the oil spill risk pose to water quality and shoreline ecosystems, and (3) validating model predictions using satellite images. 165 satellite images acquired by SENTINEL-1A, LANDSAT-8, RADARSAT, ENVISAT and ERS sensors between 1996 and 2015 were used for the detection of oil spills using object-based classification and visual interpretation. Anthropogenic hotspots were observed at three oldest oil production sites with estimated oil spilling up to 1264 m3 per day and different degrees of temporal repetition of oil spills. The largest area (5639 km2) experienced 1–10 detected oil spills, while 993 km2 experienced 11–20 oil spills, 775 km2 experienced 21–50 oil spills, 208 km2 experienced 51–100 oil spills, and 36 km2 experienced 101–150 oil spills. The majority (83% or 6157 km2) of sea surface area within the combined boundary of detected oil spills (7422 km2) had a 50% or greater chance of oil spill contamination. Approximately, 6% (44 km of 751 km) of shoreline had a 50% or greater probability of contamination with land use classes sensitive to pollution.
Ecohydrology | 2018
Jenna Keany; Mary C. Christman; Mikaila Milton; Karen L. Knee; Heather Gilbert; David C. Culver
Department of Environmental Science, American University, Washington, DC MCC Statistical Consulting LLC, Gainesville, Florida Department of Biology and Statistics, University of Florida, Gainesville, Florida National Capital Parks‐East, National Park Service, Washington, DC Correspondence Jenna Keany, Department of Environmental Science, American University, 4400 Massachusetts Ave. NW, Washington, DC 20016. Email: jenna.keany@gmail.com Funding information Chesapeake Watershed Cooperative Ecosystem Studies Unit, Grant/Award Number: P16AC01389
Marine Chemistry | 2008
Joseph H. Street; Karen L. Knee; Eric E. Grossman; Adina Paytan
Limnology and Oceanography | 2010
Karen L. Knee; Joseph H. Street; Eric E. Grossman; Alexandria B. Boehm; Adina Paytan
Environmental Science & Technology | 2007
Elizabeth Derse; Karen L. Knee; Scott D. Wankel; Carol Kendall; Carl J. Berg; Adina Paytan
Environmental Science & Technology | 2009
Frank J. Black; Adina Paytan; Karen L. Knee; Nicholas R. de Sieyes; Priya M. Ganguli; E. T. Gray; A. Russell Flegal
Estuaries and Coasts | 2008
Karen L. Knee; Blythe A. Layton; Joseph H. Street; Alexandria B. Boehm; Adina Paytan
Continental Shelf Research | 2014
Kimberly A. Null; Karen L. Knee; Elizabeth D. Crook; Nicholas R. de Sieyes; Mario Rebolledo-Vieyra; Laura Hernández-Terrones; Adina Paytan
Estuaries and Coasts | 2012
Kimberly A. Null; Natasha T. Dimova; Karen L. Knee; Bradley K. Esser; Peter W. Swarzenski; Michael J. Singleton; Mark T. Stacey; Adina Paytan