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 Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München

nachricht Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>