USGS Columbia Environmental Research Center: Cathy Richter, PhD (Research Molecular Biologist)

In The News

• EPA, Stay Focused! Email Spats Don't Change the Science on Atrazine - It's Bad!
  Tuesday, August 24, 2010
  (NRDA)
  The EPA and USGS have found this chemical in almost every waterway where they have looked for it, and USGS even identified an association between contaminated streams and impaired fish reproduction. Our report also features a rundown of the most current science on the health impact of the pesticide, which references the work of Hayes’ lab that has been published in the peer-reviewed scientific journals, along with the published research of dozens of other scientists that all provide evidence of atrazine’s harms.  Read More
• Common Herbicide is Harmful to Fish
  Friday, June 25, 2010
  (Practical Fishkeeping)
  The study was conducted by Donald Tillitt and a team of researchers at the Environmental Research Center in Columbia. The team exposed fathead minnows Pimephales promelas to levels of atrazine varying from 0-50 micrograms - all below the 'USEPA Office of Pesticides Aquatic Life Benchmark' of 65 micrograms per litre for chronic exposure of fish.  Read More
• Work Shows Atrazine’s Potential Harm
  Sunday, May 30, 2010
  (Columbia Daily Tribune)
  In an unrelated study, Don Tillitt, a research chemist at the U.S. Geological Survey’s Columbia Environmental Research Center, found that fathead minnows exposed to Atrazine produce fewer eggs and spawn less often than control groups. The study is one of the first to suggest that Atrazine can be harmful to fish at levels far lower than the benchmarks set by the Environmental Protection Agency.  Read More
• Study Finds Atrazine Exposure Impairs Fish Reproduction
  Thursday, May 20, 2010
  (NRDC Switchboard)
  Now researchers with the United States Geological Survey have shown that atrazine exposure can also lower fish reproduction and cause abnormalities in fish reproductive organs.  Read More
• Commonly Used Atrazine Herbicide Adversely Affects Fish Reproduction
  Thursday, May 20, 2010
  (Science Centric)
  Fathead minnows were exposed to atrazine at the USGS Columbia Environmental Research Centre in Columbia, Mo., and observed for effects on egg production, tissue abnormalities and hormone levels. Fish were exposed to concentrations ranging from zero to 50 micrograms per litre of atrazine for up to 30 days. All tested levels of exposure are less than the USEPA Office of Pesticides Aquatic Life Benchmark of 65 micrograms per litre for chronic exposure of fish. Thus, substantial reproductive effects were observed in this study at concentrations below the USEPA water-quality guideline.  Read More
• New Study Finds Weed Killer Hurts Fish Spawning
  Wednesday, May 19, 2010
  (Baltimore Sun)
  USGS scientists, in a study published in the journal Aquatic Toxicology, reported that fathead minnows did not spawn as much or as well when exposed in the laboratory to concentrations of the pesticide below what's found in the wild. Exposed fish produced fewer eggs, and researchers observed abnormalities in reproductive tissues of exposed males and females.  Read More
• Commonly Used Atrazine Herbicide Adversely Affects Fish Reproduction
  Wednesday, May 19, 2010
  (Science Daily)
  Atrazine, one of the most commonly used herbicides in the world, has been shown to affect reproduction of fish, according to a new U.S. Geological Survey (USGS) study.  Read More
• Common Herbicide Atrazine Affects Fish Reproduction
  Wednesday, May 19, 2010
  (Yahoo! Health)
  The farm herbicide atrazine, used widely worldwide, has been shown to affect reproduction in fish, according to a US government study released Wednesday.  Read More
• Atrazine Affects Fish Reproduction
  Wednesday, May 19, 2010
  (United Press International (UPI))
  "Concentrations of atrazine commonly found in agricultural streams and rivers caused reduced reproduction and spawning, as well as tissue abnormalities in laboratory studies with fish," said USGS scientist Donald Tillitt, who led the research.  Read More