Killer Whales Metabolize Contaminants, Yet Still Show Record-High Contamination Levels

(July 21, 2007) — Killer whales hold the gloomy record of being the most-polluted European arctic mammal, says a new study published in the latest issue of Environmental Toxicology and Chemistry. Levels of contaminants measured in whales near Norway were among the highest ever measured in marine mammals, exceeding levels found in harbor seals, polar bears, and white whales.
Killer whales are widely distributed marine mammals capable of surviving on a variety of foods. In this study, blubber samples were taken, using a dart gun, from eight live, free-ranging whales. Contamination levels were six to 20 times higher in killer whales compared to other high-Arctic species, such as white whales.
Very high levels of halogenated organic contaminants (HOCs), including polychlorinated biphenyls (PCBs) and chlorinated pesticides were found in the tissues of killer whales, apparently due to their high concentration in the whales’ primary diet source, herring.
Despite the ban on most PCBs, toxaphene, and DDT, these compounds pose a continuing threat to the health of humans and marine organisms. New HOCs, such as the polybrominated diphenyl ethers (PBDEs) which are used as flame retardants, continue to be released into the environment.
Organisms are particularly vulnerable to HOCs in the marine environment. Because of the low water solubility of these compounds, exposure through the food web leads to the highest concentrations in marine mammals. Several studies have demonstrated adverse effects on the endocrine and immune systems of some marine mammals.
While most HOCs are considered to be poorly metabolized, killer whales in this study had lower levels of certain PCBs, pesticides (chlordane, DDE), toxaphene, and PBDEs than expected, suggesting an ability to metabolize them. This was unexpected, because other marine mammals, such as dolphins and white whales, show a much lower ability to metabolize HOCs.
WildLife Rules! Help Save WildLife

aggag,15,Backyard,41,Barbed Wire,3,Birds,77,Bob Irwin,9,Books,2,Butterflies,1,cat,11,Cats-Big,7,commercial animals,22,Dingoes,8,Echidna,3,Events,6,Frog,3,Insects,10,introduced species,19,Kangaroo,41,Koala,20,MISC,28,NewsLetters,3,Ocean,32,Pics,10,polls,2,possum,34,Promoting,41,Quotes,17,Rehab,46,Reptiles,25,Rescue,12,Spiders,5,Vegetation,22,Video,134,WebSites-wildlife,33,Whales,20,Wildlife Issues,87,Wombat,3,
WildLife Rules!: Killer Whales Metabolize Contaminants, Yet Still Show Record-High Contamination Levels
Killer Whales Metabolize Contaminants, Yet Still Show Record-High Contamination Levels
WildLife Rules!
Loaded All Posts Not found any posts VIEW ALL Readmore Reply Cancel reply Delete By Home PAGES POSTS View All RECOMMENDED FOR YOU LABEL ARCHIVE SEARCH ALL POSTS Not found any post match with your request Back Home Sunday Monday Tuesday Wednesday Thursday Friday Saturday Sun Mon Tue Wed Thu Fri Sat January February March April May June July August September October November December Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec just now 1 minute ago $$1$$ minutes ago 1 hour ago $$1$$ hours ago Yesterday $$1$$ days ago $$1$$ weeks ago more than 5 weeks ago Followers Follow THIS CONTENT IS PREMIUM Please share to unlock Copy All Code Select All Code All codes were copied to your clipboard Can not copy the codes / texts, please press [CTRL]+[C] (or CMD+C with Mac) to copy