CERC Branch: Biochemistry / Physiology

In The News

• Feminized Fish: A Side Effect of Emerging Contaminants
  Thursday, September 13, 2012
  (EarthFix, KUOW, 94.9 FM, Public Broadcasting)
   Read More
• PCBs Eating Away at Turtles
  Wednesday, November 23, 2011
  (Discovery News)
  Chemicals (PCBs) that have lingered in the environment for decades may be eating away at the bones of turtles, and maybe, us. PCBs, once commonly used in pesticides and a wide variety of industrial fluids, have been banned for decades. But with very slow breakdown times, they are still widespread in the environment, particularly in more developed areas.  Read More
• Are They Boy or Girl Fish? It’s Now Harder to Tell
  Tuesday, January 11, 2011
  (Leavenworth Times, Leavenworth, KS)
  According to the US Geological Survey, intersex, the presence of both male and female characteristics within the same fish, is being observed in fish in more streams across the nation. Intersex is one manifestation of endocrine disruption in fish, which can also result in adverse effects on the development of the brain and nervous system, the growth and function of the reproductive system, and the response to stressors in the environment.  Read More
• Is Your Birth Control Making Male Fish Sprout Ovaries?
  Wednesday, December 08, 2010
  (The Pitch Blogs)
  Ecologists keep tabs on sturgeon, a prehistoric fish that likes the Missouri River's muddy waters. The pallid sturgeon and the lake sturgeon are endangered, and the more common shovelnose sturgeon has become "a species of concern."  Read More
• Columbia Researchers Study Intersex Sturgeon in Missouri River
  Tuesday, December 07, 2010
  (Columbia Missourian)
  Ecologist Aaron DeLonay, with the U.S. Geological Survey, holds a shovelnose sturgeon netted just east of Jefferson City on the Missouri River that he estimates to be 3 or 4 years old Oct. 29. DeLonay and a small team of scientists go out on the river frequently to check on the reproductive condition of a more rare fish, the pallid sturgeon, to see, and in some cases ensure, successful reproduction. Whenever DeLonay and his team catch a pallid sturgeon that they have not caught before, they implant a tracking device that, other than tracking water depth and temperature, can be used to determine if the fish mated.  Read More
• Rise of the She-Fish?
  Wednesday, August 25, 2010
  (Santa Fe Reporter)
  Scientists want to know if Rio Grande contaminants are feminizing the endangered silvery minnow.  Read More
• 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
• Results of Extensive Long-term Studies Demonstrate the Safety of Atrazine to Fish Populations
  Thursday, May 20, 2010
  (Syngenta.com)
  Investigations of the risk of atrazine on fish reproduction, as called for by Tillitt et al. (2010) in a USGS report, have already been conducted in multiple multi-generational tests.  The results of these extensive long-term studies demonstrate the safety of atrazine to fish populations.  The results reported by Tillitt are inconsistent with the results of four full life-cycle fish studies which report no effects on reproduction, two of which were for the same species (fathead minnow) of fish. These four studies were conducted using a standard protocol, reviewed and accepted by the USEPA.
  In addition, other studies conducted report no effect on fish. A USEPA (2005) study was conducted using methods similar to those of Bringolf et al. (2004) and Tillitt. Results indicate that atrazine exposure to levels as high as 223 milligrams per liter (the highest concentration tested) had no effect on reproduction.  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
• Pharmed Fish
  Thursday, April 01, 2010
  (Trout, quarterly magazine of Trout Unlimited)
  In the Spring issue of Trout, a quarterly magazine of Trout Unlimited, is a feature story, "Pharmed Fish: Are Pharmaceuticals and Other Pollutants to Blame for Alarming Numbers of Intersex Fish?", highlighting USGS fish health research by Jo Ellen Hinck, conducted over a 10-year period across nine U.S. river basins, the Nation's first comprehensive look at fish health including the intersex condition.  Read More
• Something Fishy in the Water
  Wednesday, November 25, 2009
  (CBS Evening News with Katie Couric)
  Dean Reynolds, Correspondent: "Something strange is happening to the fish in America's rivers, lakes and ponds. Chemical pollution seems to be disrupting their hormones, blurring the line between male and female."  text  Read More