Michael T Meyer, Ph.D.
Science and Products
Investigating the influence of nitrate nitrogen on post-smolt Atlantic salmon Salmo salar reproductive physiology in water recirculation aquaculture systems
A major issue affecting land-based, closed containment Atlantic salmon Salmo salar growout production in water recirculation aquaculture systems (RAS) is precocious male maturation, which can negatively impact factors such as feed conversion, fillet yield, and product quality. Along with other water quality parameters, elevated ...Good, Christopher; Davidson, John; Iwanowicz, Luke R.; Meyer, Michael T.; Dietze, Julie E.; Kolpin, Dana W.; Marancik, David; Birkett, Jill; Williams, Christina; Summerfelt, Steven T.
Expanded target-chemical analysis reveals extensive mixed-organic-contaminant exposure in USA streams
Surface water from 38 streams nationwide was assessed using 14 target-organic methods (719 compounds). Designed-bioactive anthropogenic contaminants (biocides, pharmaceuticals) comprised 57% of 406 organics detected at least once. The 10 most-frequently detected anthropogenic-organics included eight pesticides (desulfinylfipronil, AMPA,...Bradley, Paul M.; Journey, Celeste A.; Romanok, Kristin; Barber, Larry B.; Buxton, Herbert T.; Foreman, William T.; Furlong, Edward T.; Glassmeyer, Susan T.; Hladik, Michelle L.; Iwanowicz, Luke R. ; Jones, Daniel K.; Kolpin, Dana W.; Kuivila, Kathryn M. ; Loftin, Keith A.; Mills, Marc A.; Meyer, Michael T.; Orlando, James L. ; Reilly, Timothy J.; Smalling, Kelly L. ; Villeneuve, Daniel L.
Methods used to characterize the chemical composition and biological activity of environmental waters throughout the United States, 2012-14
A vast array of chemical compounds are in wide commercial use in the United States, and the potential ecological and human-health effect of exposure to chemical mixtures has been identified as a high priority in environment health science. Awareness of the potential effects of low-level chemical exposures is rising. The U.S. Geological Survey, in...Romanok, Kristin M. ; Reilly, Timothy J.; Barber, Larry B.; Boone, J. Scott; Buxton, Herbert T.; Foreman, William T. ; Furlong, Edward T.; Hladik, Michelle; Iwanowicz, Luke R. ; Journey, Celeste A.; Kolpin, Dana W.; Kuivila, Kathryn ; Loftin, Keith A.; Mills, Marc A.; Meyer, Michael T.; Orlando, James L. ; Smalling, Kelly L. ; Villeneuve, Daniel L.; Bradley, Paul M.
Similarities and differences in occurrence and temporal fluctuations in glyphosate and atrazine in small Midwestern streams (USA) during the 2013 growing season
Glyphosate and atrazine are the most intensively used herbicides in the United States. Although there is abundant spatial and temporal information on atrazine occurrence at regional scales, there are far fewer data for glyphosate, and studies that compare the two herbicides are rare. We investigated temporal patterns in glyphosate and atrazine...Mahler, Barbara J.; Van Metre, Peter C.; Burley, Thomas E.; Loftin, Keith A.; Meyer, Michael T.; Nowell, Lisa H.
Exposure to the contraceptive progestin, gestodene, alters reproductive behavior, arrests egg deposition, and masculinizes development in the fathead minnow (Pimephales promelas)
Endogenous progestogens and pharmaceutical progestins enter the environment through wastewater treatment plant effluent and agricultural field runoff. Lab studies demonstrate strong, negative exposure effects of these chemicals on aquatic vertebrate reproduction. Behavior can be a sensitive, early indicator of exposure to environmental...Frankel, Tyler E.; Meyer, Michael T.; Kolpin, Dana W.; Gillis, Amanda B.; Alvarez, David A.; Orlando, Edward F.
Concentrations of glyphosate and atrazine compounds in 100 Midwest United States streams in 2013
Temporal patterns in glyphosate and atrazine concentrations were measured weekly by the U.S. Geological Survey (USGS) during the 2013 growing season in 100 small streams in the Midwestern United States. Concentrations also were measured every 2 days at a subset of 8 of the sites, all located in Missouri. Glyphosate was detected more frequently in...Mahler, Barbara J.; Van Metre, Peter C.; Burley, Thomas E.; Loftin, Keith A.; Meyer, Michael T.; Nowell, Lisa H.
Aqueous exposure to the progestin, levonorgestrel, alters anal fin development and reproductive behavior in the eastern mosquitofish (Gambusia holbrooki)
Endogenous progestogens are important regulators of vertebrate reproduction. Synthetic progestins are components of human contraceptive and hormone replacement pharmaceuticals. Both progestogens and progestins enter the environment through a number of sources, and have been shown to cause profound effects on reproductive health in various aquatic...Frankel, Tyler E.; Meyer, Michael T.; Orlando, Edward F.
Cyanotoxins in inland lakes of the United States: Occurrence and potential recreational health risks in the EPA National Lakes Assessment 2007
A large nation-wide survey of cyanotoxins (1161 lakes) in the United States (U.S.) was conducted during the EPA National Lakes Assessment 2007. Cyanotoxin data were compared with cyanobacteria abundance- and chlorophyll-based World Health Organization (WHO) thresholds and mouse toxicity data to evaluate potential recreational risks....Loftin, Keith A.; Graham, Jennifer L.; Elizabeth Hilborn; Sarah Lehmann; Meyer, Michael T.; Dietze, Julie E.; Griffith, Christopher
Total cylindrospermopsins, microcystins/nodularins, and saxitoxins data for the 2007 United States Environmental Protection Agency National Lake Assessment
Phytoplankton communities in freshwater lakes, ponds, and reservoirs may be dominated by cyanobacteria (also called blue-green algae) under certain environmental conditions. Cyanobacteria may cause a range of water-quality impairments, including the potential for toxin production. Cyanobacteria toxins (cyanotoxins) may adversely impact human and...Loftin, Keith A.; Dietze, Julie E.; Meyer, Michael T.; Graham, Jennifer L.; Maksimowicz, Megan M.; Toyne, Kathryn D.
Contamination with bacterial zoonotic pathogen genes in U.S. streams influenced by varying types of animal agriculture
Animal waste, stream water, and streambed sediment from 19 small (< 32 km2) watersheds in 12 U.S. states having either no major animal agriculture (control, n = 4), or predominantly beef (n = 4), dairy (n = 3), swine (n = 5), or poultry (n = 3) were tested for: 1) cholesterol,...Haack, Sheridan K.; Duris, Joseph W.; Kolpin, Dana W.; Focazio, Michael J.; Meyer, Michael T.; Johnson, Heather E.; Oster, Ryan J.; Foreman, William T.
Polyoxyethylene tallow amine, a glyphosate formulation adjuvant: Soil adsorption characteristics, degradation profile, and occurrence on selected soils from agricultural fields in Iowa, Illinois, Indiana, Kansas, Mississippi, and Missouri
Polyoxyethylene tallow amine (POEA) is an inert ingredient added to formulations of glyphosate, the most widely applied agricultural herbicide. POEA has been shown to have toxic effects to some aquatic organisms making the potential transport of POEA from the application site into the environment an important concern. This study characterized the...Tush, Daniel L.; Meyer, Michael T.
Water-quality characteristics indicative of wastewater in selected streams in the upper Neuse River Basin, Durham and Orange Counties, North Carolina, from 2004 to 2013
Data were collected during three time periods to assess the effects of wastewater treatment and disposal practices on the occurrence of selected contaminants indicative of wastewater in the upper Neuse River Basin, North Carolina. The first phase of data collection, December 2004 to June 2005, and the second phase, April to October 2008, addressed...Ferrell, Gloria M.; Yearout, Matthew S.; Grimes, Barbara H.; Graves, Alexandria K.; Fitzgerald, Sharon A.; Meyer, Michael T.