Our Pollution Has Now Reached Deep-Sea Animals

Dr. Alan Jamieson, Newcastle University
Dr. Alan Jamieson, Newcastle University / Dr. Alan Jamieson, Newcastle University

It seems nowhere on Earth is safe from the creeping, deadly fingers of pollution. Scientists analyzing deep-sea crustaceans found traces of manmade chemicals in the animals’ bodies. The researchers published their findings in the journal Nature Ecology & Evolution.

Amphipods, like the one shown above, are small, eyeless crustaceans that make their homes in the deepest, darkest parts of the ocean. The key to the deepwater amphipod’s survival is its stomach; it is both notoriously unfussy about what it eats, and gifted with special enzymes that help it digest just about anything, including plastic, animal carcasses, and even sunken ships.

But the oceans are a risky place to dine these days. Scientists have found dangerous chemicals, fibers, and pieces of plastic in the bodies of seabirds, mammals, mollusks, and fish alike.

The question for oceanographer Alan Jamieson and his colleagues was simple: How far down do these pollutants go?

To find out, they used deep-sea landers to collect three species of amphipods from the Mariana and Kermadec Trenches in the Pacific Ocean. They brought the animals back to the lab and tested their fatty tissue, looking for traces of 14 different pollutants.

And there they were. High levels of pollutants, including flame retardant chemicals, were found in every sample from every species, regardless of the depth at which the sample was collected. The contamination was so bad, it was comparable to that found in Japan's Suruga Bay, long known for its high level of industrial pollution.

The authors say the chemicals most likely reached the trenches while clinging to pieces of plastic garbage or the bodies of dead animals from closer to the surface.

Biologist Katherine Dafforn of the University of New South Wales weighed in on the research in an accompanying editorial. She concludes that “Jamieson et al. have provided clear evidence that the deep ocean, rather than being remote, is highly connected to surface waters and has been exposed to significant concentrations of human-made pollutants.”