The Problem of PCB's in our Waters
The Problem of PCBs in our Waters
There is concern that lingering toxic chemical pollution is going to lead to the extinction of marine life, especially killer whales. The chemicals also affect mammals such as dolphins.
What is PCB and what is happening?
PCBs are chemicals that used to be used in electrical equipment, but they were banned in the 1980’s after they were found to be toxic. The chemicals are still seeping into the oceans however, and high levels have been found in dolphins in European waters.
Research that analysed the levels of PCBs in dolphins and killer whales over the last 20 years, found that levels of the chemicals in the mammals far exceeded the level at which they becomes severely toxic.
PCB affects breeding and the immune systems of mammals who ingest it.
The extinction of killer whales
Killer whales could be found in the North Sea until the 1960s, and in the Mediterranean until the 1980s. But now there are just 8 whales left in the UK’s last pod off north-west Scotland. The group have not produced a calf in the 19 years that scientists have been studying them. Now it is feared that they will become extinct.
Where does PCB come from?
The PCBs that were used in products before they were banned are still thought to be on land and haven’t been disposed of. Most of the PCBs that end up in waterways have leaked from landfill sites.
Why is it so bad for marine life?
PCBs are such a big problem for killer whales and dolphins because they are at the top of the food chain in the ocean and they live for such a long time. The toxins are eaten by feeders on the ocean floor, then by larger animals like crabs, and then by fish. The toxins pass all the way through the food chain and eventually end up reaching the whales and dolphins.
The high levels of PCBs found in female whales and dolphins indicates they are not reproducing offspring, and even when they do, PCBs are passed to the young via their milk, thereby carrying on the trail of toxic devastation.
An ongoing problem
PCBs were banned in the UK in 1981 and across the European Union by 1987, but levels present in marine animals remain high, so this proves that the toxins are still present in the environment.
PCBs are deigned to be virtually unbreakable so it is difficult to get rid of them, and they are usually buried or incinerated at very high temperatures.
Conservation groups are concerned that while people are aware of animals getting caught up in fishing nets, and the practise of whaling, PCBs are virtually a silent killer. When the sea bed is drilled, or dredged, it brings toxins back up that may have been buried.