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:2/2/2016)... Feb. 2, 2016 This BCC Research ... market by reviewing the recent advances in high ... drive the field forward. Includes forecast through 2019. ... the challenges and opportunities that exist in the ... solution developers, as well as IT and bioinformatics ...
(Date:2/2/2016)...   Parabon NanoLabs (Parabon) announced today ... Office and the Defense Forensics and Biometrics Agency ... company,s Snapshot Kinship Inference software for ... defense-related DNA forensics.  Although Snapshot is best known ... ancestry from DNA evidence), it also has the ...
(Date:2/1/2016)... , Feb. 1, 2016  Today, the first day ... announced plans to develop a first of its kind ... of IBM Watson. In the first application of ... (NYSE: IBM ), and Welltok will create a ... assessments with cognitive analytics, delivered on Welltok,s health optimization ...
Breaking Biology News(10 mins):
(Date:2/11/2016)... Calif. , Feb. 11, 2016  Dovetail Genomics™ ... to its beta program for a planned metagenomic genome ... present the company,s metagenomic genome assembly method in a ... in Genome Biology & Technology conference in ... of these highly complex datasets is difficult. Using its ...
(Date:2/11/2016)... ... February 11, 2016 , ... Reichert ... years, continues today to pursue the highest level of accuracy and quality with ... AR9 Refractometer and the AR5 Refractometer. Accurate, reliable and tough enough for ...
(Date:2/10/2016)... MONTREAL , Febr. 10, 2016 /PRNewswire/ - BioAmber Inc. ... is pleased to announce that Mitsui & Co. Ltd., ... bio-based succinic acid plant, is investing an additional CDN$25 ... equity, increasing its stake from 30% to 40%.  Mitsui ... of bio-succinic acid produced in Sarnia ...
(Date:2/10/2016)... 2016 NX Prenatal Inc., a US ... technology for early warning of adverse pregnancy outcomes, ... study by Dr. Thomas McElrath of ... Fetal Medicine,s (SMFM) annual meeting held in ... 2016.  The presentation reported initial positive top-line results ...
Breaking Biology Technology: