Advertisement

Dolphins and Beluga Whales accumulate pollutants

Time to read
2 minutes
Read so far

Dolphins and Beluga Whales accumulate pollutants

Wed, 12/10/2011 - 22:22
Posted in:

Wildlife from remote locations have been shown to bioaccumulate perfluorinated compounds (PFCs) in their tissues.

Atlantic Bottlenose Dolphins

Persistent organic pollutants (POPs) can spread globally through air and water, accumulate in the food chain, and may have carcinogenic, neurodevelopmental, immune or endocrine effects on both wildlife and humans.

Biopsies

POP including legacy POPs (PCBs, chlordanes, mirex, DDTs, HCB, and dieldrin) and polybrominated diphenyl ether (PBDE) flame retardants were determined in 300 blubber biopsy samples from coastal and near shore/estuarine male bottlenose dolphins (Tursiops truncatus) sampled along the U.S. East and Gulf of Mexico coasts and Bermuda

To study POP concentrations in male bottlenose dolphins (Tursiops truncatus) , researchers from the National Institute of Standards and Technology (NIST), the National Oceanic and Atmospheric Administration (NOAA), the Duke University Marine Laboratory, Florida State University and the Chicago Zoological Society teamed up to collect and examine blubber biopsy samples from 2000 to 2007 at eight locations along the U.S. East Coast (from New Jersey to Eastern Florida), five sites in the eastern Gulf of Mexico and off Bermuda.

Analysis

The researchers analyzed the dolphin blubber for POPs that were once used as insecticides (such as DDT), insulating fluids (polychlorinated biphenyls, or PCBs), flame retardants (polybrominated diphenyl ethers, or PBDEs) and fungicide hexachlorobenzene, or HCB).

Highest levels near urban areas

Overall, PCBs were the pollutants found in the highest concentrations across the 14 sampling locations, followed by DDT, other pesticides and PBDEs, and HCB. Levels for POPs were statistically higher in dolphins living and feeding in waters near more urban and industrialized areas.

Second study - belugas in Alaska

In the second study, a NIST team analyzed the levels of 12 PFCs in livers harvested from 68 beluga whales (Delphinapterus leucas) that had lived and fed in two Alaskan locations: Cook Inlet in the urban southern part of the state and the Chukchi Sea in the remote northern part. The samples were collected from 1989 to 2006 by Native Alaskans during subsistence hunts and stored at NIST’s National Marine Mammal Tissue Bank (NMMTB). This was the first study to look at the concentration of PFCs in belugas from Alaska.

PFCs have been used as nonstick coatings and additives in a wide variety of goods including cookware, furniture fabrics, carpets, food packaging, fire-fighting foams and cosmetics. They are very stable, persist for a long time in the environment and are known to be toxic to the liver, reproductive organs and immune systems of laboratory mammals.

Detected in whale livers

PFCs were detected in all of the beluga livers, with two compounds—perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonamide (PFOSA)—found in more than half the samples. All but one of the PFC concentrations measured were significantly higher in the Cook Inlet belugas, an expected result given the nearby urban, industrialized area. The exception was PFOSA, where levels were higher amongst the Chukchi Sea whales.

The researchers are unsure if this is the result of the pollutant being carried into the remote region by ocean currents, atmospheric transport or a combination of both. They also found that PFC concentrations in belugas increased significantly over the seven-year study period and were mostly higher in males.

Sources
Environmental Science & Technology
Advertisements