Human population is not the cleanest. We are responsible for polluting soil, water and air and causing irreversible changes in Earth‘s climate. However, even scientists who are well aware of that recently got another shock – industrial chemicals have recently been found 10 km below sea surface.
Scientists from University of New South Wales have detected high concentrations of pollution at the bottom of two of the Earth’s deepest oceanic trenches. This just reveals once more how far-reaching human activity is in damaging planet’s ecosystems. This discovery was made by collecting samples of tiny marine crustaceans that live in extreme depths of the ocean. Scientists analysed these samples and were shocked to find that they contained high levels of chemicals, similar to those found in highly industrialised areas. As disturbing as it is, scientists were actually thinking that a surprising discovery may be made just because of how poorly bottom of the ocean is known to us. In fact, there is an old saying that we know more about the surface of the Moon than Earth’s oceans.
Not only this discovery shows how far-reaching human pollution is, but it also reveals that bottom of the ocean is not disconnected from the entire ecosystem. In fact, it is closely related to the surface layers. Although it does not seem too surprising, since water mixes all the time, but ocean in these trenches is so deep that it looks like it is an entirely different world with its own life forms. Now it is clear that even they are exposed to high levels of human pollutants. Dr Katherine Dafforn, one of the researches in the project, said: “this is significant since the trenches are many miles away from any industrial source and suggests that the delivery of these pollutants occurs over long distances, despite regulations since the 1970s”. In fact, concentration of industrial pollutants in these tiny crustaceans was 50 times greater than in crabs from a highly polluted river system in China.
There are some other interesting details worth mentioning. Scientists used deep-sea landers to collect the samples from such deep trenches. Two of the deepest areas in Earth’s oceans are Mariana and Kermadec trenches and both of them had pollutants in them. Scientists say that these pollutants probably found their way to the bottom of the ocean with contaminated plastic, which was later consumed by tiny organisms living there.
However, a lot of research remains of scientists “To do” list, as the effects of these pollutants and their potential to biomagnify up the food chain are still not very well known. This is why they will continue their research and will hopefully reveal some information, which will be useful in efforts to protect these vulnerable ecosystems.