Question: Scientists are warning that killer whales and dolphins could be wiped out by which banned pollutant?
Answer: PCB – The use of the PCB chemical was prohibited from the 1980s but it still exists in the environment.
In Europe’s oceans, killer whales and dolphin’s numbers are dwindling to dangerously low levels.
When a marine mammal is found dead, a forensic investigation gets underway as soon as possible, and due to the deterioration of marine life scientists have been growing increasingly worried. At the zoological society of London, they have been trying to work out what has been causing the decline.
Scientists are finding in case after case that these animals bodies are loaded with a toxic chemical which was supposed to be a problem long gone. PCBs or Polychlorinated Biphenyls were once found in many manmade products such as:
In the 1970’s bans were put into place worldwide after it was realised that these man-made chemicals were in fact toxic and harmful.
Despite the obvious danger and the bans that have been in place for almost 50 years, PCBs have managed to stick around, with many landfill sites containing the materials that they were used in. Unfortunately, the PCBs are also leaking into the waterways and working their way into the marine food chain.
Scientists are saying that the levels of the PCBs in some species in Europe are the highest in the world and great levels of contamination can cause a range of different effects to the wildlife. The side effect that they are most worried about is the suppression of reproduction.
After dissection of the marine mammals that have been found dead in the oceans, the scientists are finding growing cases where the animals have been pregnant but the PCBs have caused an infection which in turn killed the mother and its calf.
This is not the first time that the world’s marine life has faced problems with PCBs. We have had very similar problems in other marine mammals in the past such as the seals in the Baltic. Thanks to the reduction in PCBs in the waterways, the seal population is now recovering, but the problem still has not completely subsided.
Chief Scientific Adviser Ian Boyd says that “We can deal with this, but it takes quite a lot of time to take these PCBs out of the system”. The last thing that we want is for these giants of the seas to become a thing of the past. More needs to be done to prevent these chemicals from reaching the oceans.
What are your thoughts on this matter and why do you think we are still finding large amounts of PCBs being used in manufacturing?
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