Navigation Links
Contaminants linked to sturgeon decline in Columbia river

White sturgeon populations in the Columbia River may be declining due to the presence of elevated amounts of foreign chemicals including DDT and polychlorinated biphenyls in their bodies, according to new studies by researchers at Oregon State University.

The research by Carl Schreck and Grant Feist, biologists in OSU's College of Agricultural Sciences, has been published in the journals Environmental Health Perspectives and Archives of Environmental Contamination and Toxicology.

Their research shows that white sturgeon living in the Columbia River in some areas above Bonneville Dam have high amounts of toxic contaminants in their livers, sex organs and muscle tissue.

"We don't know the exact source of contamination," Schreck said. "The fish move, the stuff they eat moves and the water and sediments bearing the contaminants moves. The Columbia receives input from numerous sources, so any population of fish at any one site can be exposed to a myriad of substances."

The OSU researchers say it is difficult to estimate the numbers of sturgeon in the Columbia, but there has been a noticeable decline in the number of young fish, indicating productivity is poor, especially in the impounded areas above dams.

In the past, any decreases in population were thought to be linked to the presence of dams, which have changed the temperature and flow of the river. And despite fish ladders in place for salmon, the bottom-dwelling white sturgeon rarely navigate dams successfully making it difficult for them to expand their habitat or access oceanic food sources.

Schreck and Feist studied white sturgeon from three reservoirs along the Columbia River and from areas downstream of Bonneville, the last dam on the river in its path to the Pacific Ocean. The researchers found some of the fish living in reservoirs behind the dams had concentrations of chemicals up to 20 times higher than the fish below Bonneville. The contamination was most sig nificant in the reservoir behind the Bonneville Dam, the oldest dam on the river.

"We believe that some contaminants are accumulating behind the dams by settling out in the sediment as the water slows," Feist said, adding that at this point this is a hypothesis.

"Fish residing in the reservoir behind the oldest dam had the highest contaminant loads," Feist added, "and exhibited reduced growth and reproductive fitness when compared to fish sampled in other locations. These data suggest that some contaminants may be accumulating behind dams over time."

North America's largest freshwater fish, white sturgeon can grow to 20 feet in length, weigh more than 1,500 pounds and live for more than a century. The fish have always been an important food source for Oregon's Native Americans, and now as salmon runs diminish, white sturgeon fillets and steaks are increasingly sold in fish markets.

But because of their potentially high contaminant levels, Schreck cautions consumers to not eat the fish at every meal.

During the last 25 years, white sturgeon have experienced a sharp drop in population in the upper reaches of the Columbia River. In 1990, the Committee on the Status of Endangered Wildlife in Canada designated the white sturgeon as "vulnerable," only to reclassify it as "critically imperiled" in 1994.

Today, the fish, which are caught commercially and for sport on the lower Columbia, are listed as endangered in Canada. Fishing for white sturgeon is regulated by the state, with size limits precluding anglers from taking juvenile fish or large, older fish.


'"/>

Source:Oregon State University


Related biology news :

1. Newly discovered virus linked to childhood lung disorders and Kawasaki disease
2. Low level of extinction during ice age linked to adaptability
3. Improved statistical tools reveal many linked loci
4. Scientists at Galileo Pharmaceuticals confirm inflammatory response linked to glucose levels
5. Attacks of King George IIIs madness linked to key metabolism molecule
6. Gene controlling circadian rhythms linked to drug addiction
7. Physical and functional interaction of key cell growth molecules linked to cancer
8. VCU Massey Cancer Center study shows enzyme linked to spread of breast cancer cells
9. Naturally occurring asbestos linked to lung cancer
10. Disappearing arctic lakes linked to climate change
11. Genes linked to treatment resistance in children with leukemia
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/9/2016)... Finland , June 9, 2016 ... National Police deploy Teleste,s video security solution to ensure the ... France during the major tournament ... data communications systems and services, announced today that its video ... Prefecture to back up public safety across the ...
(Date:6/2/2016)... June 2, 2016   The Weather Company , an ... Ads, an industry-first capability in which consumers will be able ... to ask questions via voice or text and receive relevant ... Marketers have long sought an advertising solution ... can be personal, relevant and valuable; and can scale across ...
(Date:5/20/2016)... -- VoiceIt is excited to announce its new marketing ... working together, VoiceIt and VoicePass will offer an ... slightly different approaches to voice biometrics, collaboration between ... Both companies ... "This marketing and technology partnership allows VoiceIt ...
Breaking Biology News(10 mins):
(Date:6/23/2016)...  Blueprint Bio, a company dedicated to identifying, protecting ... has closed its Series A funding round, according to ... "We have received a commitment from Forentis Fund that ... meet our current goals," stated Matthew Nunez . ... complete validation on the current projects in our pipeline, ...
(Date:6/23/2016)... 2016 On Wednesday, June 22, 2016, ... 0.22%; the Dow Jones Industrial Average edged 0.27% lower to ... down 0.17%. Stock-Callers.com has initiated coverage on the following equities: ... (NASDAQ: NKTR ), Aralez Pharmaceuticals Inc. (NASDAQ: ... BIND ). Learn more about these stocks by accessing their ...
(Date:6/23/2016)... , ... June 23, 2016 , ... ... quality, regulatory and technical consulting, provides a free webinar on Performing ... July 13, 2016 at 12pm CT at no charge. , Incomplete investigations are ...
(Date:6/23/2016)... June 22, 2016  Amgen (NASDAQ: AMGN ... QB3@953 life sciences incubator to accelerate the ... shared laboratory space at QB3@953 was created to help ... obstacle for many early stage organizations - access to ... sponsorship, Amgen launched two "Amgen Golden Ticket" awards, providing ...
Breaking Biology Technology: