Skip to content

Gender bending fish hint at potential disaster

Chemical contamination in the Red Deer and Oldman rivers is feminizing fish, according to researchers at the University of Calgary.

Chemical contamination in the Red Deer and Oldman rivers is feminizing fish, according to researchers at the University of Calgary.

Hamid Habibi, the co-author of a study published in the journal Environmental Toxicology and Chemistry, said their latest research confirms Alberta does have something to worry about — not just fish.

“I think human health should be paramount. We can either wait and deal with the disaster a few years down the road, or we can be proactive and try to study this more to provide a solution,” Habibi said on Thursday.

Habibi and Lee Jackson published their findings in the paper Presence of Natural and Anthropogenic Organic Contaminants and Potential Fish Health Impacts Along Two River Gradients in Alberta, Canada.

They found more than two dozen organic contaminants, many with hormone-like activity commonly found in wastewater or rivers impacted by human and agricultural hormone therapy drugs. Compounds detected in the water included synthetic estrogens (birth-control pills and hormone therapy drugs), a chemical used in making plastic (bisphenol A), and types of natural and synthetic steroids that are byproducts of agricultural run-off and cattle farming.

“There’s been reports of appearance of chemicals like this in other parts of the world, in other types of rivers, but it’s new here.”

Researchers tested the longnose dace minnow in 2005 and water samples were collected in 2006.

Sampling sites for the Red Deer River were at Penhold, Fort Normandeau, Riverbend near Red Deer, Joffre bridge, Nevis bridge, Tolman bridge, Morrin bridge and Drumheller.

The highest total concentrations of natural and synthetic estrogens were at Tolman and Morrin bridges. Testosterone was limited to Tolman Bridge. The plastic chemical was detected at Joffre bridge. A veterinary growth promoter was found at Fort Normandeau.

The scientists say the chemical cocktail produced through the variety of contamination is to blame.

“The potency of these chemicals increases significantly when they occur in mixtures with other compounds. That creates problems because most of the data used by Health Canada, the U.S. Environmental Protection Agency, and others are based on single chemical studies from a long time ago,” Habibi said.

He said while it’s not known whether the levels are high enough to hurt humans, there is a possible risk the chemicals could increase cancer rates or developmental abnormalities.

In some locations, female fish accounted for as much as 90 per cent of the minnow population, far higher than the normal 55 to 60 per cent.

At many of the sites studied, male fish showed elevated levels of a protein normally high only in the blood of females. Other areas have produced male fish with female eggs in their testes.

The disturbances in fish populations were greater downstream from cities than upstream and were most notable around several major cattle feedlots.

Habibi wants politicians and industry to pay attention because they’re going to have to help solve the problem.

“A solution is essentially to minimize those contaminants. One of the most important ways is to increase the efficiency of municipal sewage treatment plants to remove these contaminants. Some of them are actually coming from municipal sources.”

Habibi has high hopes for a new research facility to develop and test new approaches to treating wastewater at the City of Calgary’s new Pine Creek Wastewater Treatment Facility.

Chemical contamination has a slow effect that’s easy to forget, he warned.

“This is the tip of an iceberg. I think it’s a challenge for us that we have to meet and we can’t meet alone at the university without resources, without investment from government, from public sector to do this.”

szielinski@www.reddeeradvocate.com

— With files from The Canadian Press