Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Albatross study shows regional differences in ocean contamination

06.04.2006


As long-lived predators at the top of the marine food chain, albatrosses accumulate toxic contaminants such as PCBs, DDT, and mercury in their bodies. A new study has found dramatic differences in contaminant levels between two closely related albatross species that forage in different areas of the North Pacific. Researchers also found that levels of PCBs and DDT have increased in both species over the past ten years.

The differences in contaminant levels between black-footed and Laysan albatrosses indicate regional differences in the contamination of North Pacific waters, said Myra Finkelstein, a postdoctoral researcher at the University of California, Santa Cruz, who led the study.

"The black-footed albatrosses forage mostly in the California Current, whereas the Laysan albatrosses forage at higher latitudes near Alaska. So it appears that the California Current system has significantly higher concentrations of these contaminants," Finkelstein said.



The researchers published their findings in the April issue of the journal Ecological Applications.

Mercury and organochlorine compounds such as PCBs (polychlorinated biphenyls), DDT, and related compounds persist in the environment for a long time and build up in the tissues of animals high on the food chain. Analysis of blood samples showed that concentrations of these compounds in black-footed albatrosses were 370 to 460 percent higher than in Laysan albatrosses.

The two species breed at the same sites in the Hawaiian Islands. But when they leave their breeding colonies on foraging trips, the black-footed albatrosses head northeast toward the West Coast of North America, while Laysan albatrosses head northwest toward the northern and western regions of the North Pacific.

Black-footed and Laysan albatrosses both consume a mixed diet of squid, fish, and fish eggs. Finkelstein analyzed nitrogen isotope ratios in the two species--an indicator of an animal’s "trophic level," or how high it is on the food chain--and found no significant difference.

"Biomagnification means that you get higher concentrations of these compounds as you go up the food chain, but these species appear to be feeding at the same trophic level. We saw huge differences in contaminant levels, which we attribute, at least in part, to the differences in foraging patterns between the two species," Finkelstein said.

The high contaminant load in black-footed albatrosses foraging in the California Current probably reflects the long history of industrial and agricultural discharges along the West Coast, Finkelstein said. But she added that the distribution and transport of contaminants in the North Pacific involves processes that are still not fully understood.

Concentrations of DDE (the main breakdown product of DDT) and PCBs in both black-footed and Laysan albatrosses were 130 to 360 percent higher in the samples Finkelstein collected in 2000 and 2001 than in samples collected by previous researchers in 1991 and 1992. The increases were much greater in black-footed albatrosses than in Laysan albatrosses, Finkelstein noted. DDE concentrations, for example, increased 360 percent in black-footed and 170 percent in Laysan albatrosses.

Many countries do not regulate the manufacture and use of PCBs and DDT as strictly as the United States does now, and these compounds continue to be released into the marine environment.

"The increases we saw compared with ten years ago probably reflect the ongoing use of these chemicals in countries that border the Pacific," Finkelstein said.

The biggest current threat to albatross populations in the North Pacific is the longline fishing industry, which kills significant numbers of both black-footed and Laysan albatrosses. But the contaminants measured in this study may also take a toll. Comparable levels of these contaminants in other species, such as herring gulls and Caspian terns in the Great Lakes region, have been associated with a variety of adverse effects, including reproductive deformities, endocrine disruption, and immune system dysfunction.

"It is very difficult to show a cause-and-effect link in a wild population, but there is evidence of health impacts in other species at these contaminant levels," Finkelstein said.

Humans are exposed to the same contaminants when they eat seafood, she added.

"It is important to realize that these contaminants have long-term effects, and we are only beginning to understand many of the subtle effects they can have, such as endocrine disruption and effects on the immune system," she said. "A lot of people think this issue has been taken care of, but it is still very much a problem."

Finkelstein, who earned a Ph.D. in ocean sciences at UCSC in 2003, conducted this study as part of her thesis research. Her advisers were Donald Croll, associate professor of ecology and evolutionary biology, and Donald Smith, professor of environmental toxicology. In addition to Croll and Smith, the coauthors of the paper include UCSC researchers Bradford Keitt and Bernie Tershy; Walter Jarman of the U.N. Environmental Program; Sue Rodriguez-Pastor of the University of Colorado, Boulder; David Anderson of Wake Forest University; and Paul Sievert of the U.S. Geological Survey.

Tim Stephens | EurekAlert!
Further information:
http://www.ucsc.edu

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>