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News from Technical Sciences

In some areas, killer whales feed primarily on sea mammals and big fish like tuna and sharks and are then threatened by PCBs. In areas where the killer whales primarily feed on small fish like herring, they are less threatened. Photo: Audun Rikardsen – www.audunrikardsen.com
In areas where the killer whales primarily feed on small fish like herring, they are less threatened. Photo: Audun Rikardsen – www.audunrikardsen.com
Killer whales hunt together to gather fish in big, isolated schools. Photo: Audun Rikardsen – www.audunrikardsen.com
PCB transport in the food chains: When foreign hazardous substances enter the marine environment, they are assimilated into the first link in the food chain, phytoplankton. The phytoplankton is consumed by zooplankton, which in turn is consumed by smaller fish, etc. The chemicals accumulate in each link of the food chain, and this means that killer whales that feed on large animals in contaminated areas may contain concentrations of PCBs so high that the survival of the species is threatened. Killer whales that primarily feed on smaller fish are not threatened in the same way. 
Population development: By collecting data from around the world and loading them into population models, the researchers can see that 10 out of 19 populations of killer whales are affected by high levels of PCBs in their body. PCBs particularly affect the reproduction and immune system of the whales. The situation is worst in the oceans around Brazil and the UK where the model predicts that populations have been cut in half over the first decades since the use of PCBs became widespread. Here, the models predict a high risk that the species will disappear within a 30-40-year period. The line indicates median values, while the shaded field shows the variation.

2018.11.01 | Research

PCB pollution threatens to wipe out killer whales

More than forty years after the first initiatives were taken to ban the use of PCBs, the chemical pollutants remain a deadly threat to animals at the top of the food chain. A new study, just published in the journal Science, shows that the current concentrations of PCBs can lead to the disappearance of half of the world’s populations of killer…

You have to go against the flow and turn ideas upside down if you want to attract the attention of the VILLUM Experiment programme. Eight AU researchers have been able to do just this, and together they will be receiving DKK 15.3 million. (Ill: Colourbox)

2018.09.18 | Public / media, Staff

Experiments worth millions

The Villum Foundation is supporting bold technical and scientific research ideas for the second time. Researchers from Aarhus University are again on the list of recipients, with eight daring ideas totalling DKK 15.3 million.