Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

SMCM professor discovers cattle hormones that leak into streams and alter fish reproduction

19.12.2003


Scientist plans similar studies on tributaries of the Chesapeake Bay



A study released in early December by a group of scientists shows that hormones leaking into streams from cattle feedlots are altering the sexual characteristics of wild fish.

Edward Orlando, assistant professor of biology at St. Mary’s College of Maryland (SMCM), was the leading author in the study that included researchers from five U.S. institutions. The scientists examined minnows in three streams that flow into Nebraska’s Elkhorn River. Their findings showed "significant alterations in the reproductive biology" of fish immediately downstream from a large Nebraska cattle feedlot.


The scientists said they do not know whether the damage was caused by natural hormones in cattle or by synthetic ones administered to the animals. Their report states that the findings "clearly demonstrate" that effluent from feedlots is hormonally active, whether it is natural or synthetic. About 30 million head of cattle are raised in U.S. feedlots each year, and nearly all are implanted with growth-promoting synthetic hormones.

Orlando said the scientists took their samples from a site directly connected to a retention pond at the base of a large feedlot. Several spots along the river contained hormones, indicating that "this [result] is not due to one farm in one location." Orlando added that laboratory tests from the study showed that the feed-lot effluent-receiving site contained a complex and potent mix of androgens (male sex hormones), and estrogens (female hormones).

According to the study, published in the online version of the scientific journal Environmental Health Perspectives, the male fish had one-third less testosterone and their testes were about half as big as those of unexposed fish upstream. The female fish had about 20 percent less estrogen and 45 percent more testosterone than females from the uncontaminated stream.

The scientists caution that further investigation of livestock farms is "urgently needed if we are to understand the possible adverse effects of these compounds on aquatic ecosystem health." They say the priority should be to identify the compounds that altered the fish, and "determine whether they were natural or pharmaceutical in origin."

Hormones are used to stimulate growth in cattle and help them produce more meat and less fat. According to a 1999 survey by the U.S. Department of Agriculture, about 99% of the nation’s largest, factory-sized cattle feedlots use hormonal implants.

"Cattle can be treated with any number of androgenic or estrogenic chemicals, or combinations of synthetic androgens and estrogens," said Orlando. "We do not know what the cattle in this feedlot were treated with or what was in the effluent. This is really the first study of this kind, and there are lots of questions, but few answers, so far."

This study was conducted on wild fish in Nebraska’s Elkhorn River. It is unknown whether the hormones implanted into cattle have any effect on human beings, "but, we do know that human exposure is minimal, given that only trace amounts of these synthetic hormones remain in the meat. In contrast to humans, aquatic wildlife is exposed to an unknown concentration of synthetic and natural hormones excreted by the cattle. We know little about the potential effects of hormone containing effluent from cattle feedlots or other concentrated animal feeding operations on fish and other aquatic wildlife," said Orlando.

Orlando plans similar studies for the tributaries of the Chesapeake Bay. He is currently submitting proposals to various funding sources to conduct research.


SMCM is consistently ranked one of the best public liberal arts colleges in the na-tion by U.S. News & World Report and The Princeton Review. The Washington Post called St. Mary’s College of Maryland "a place to get an Ivy League education at a public school price."

Marc Apter | EurekAlert!
Further information:
http://www.smcm.edu/

More articles from Ecology, The Environment and Conservation:

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>