Plastic pollution in the seas is worse than we’ve thought

Each year 2 million elephants, in the form of plastic waste, enter the sea and then stay, joining the ranks of millions and millions of elephants already there. The estimated 14 million tons of plastic waste that ends up being dumped into the oceans each year these days amounts to the weight of that many elephants.

A shocking image, yes. Here is another: by 2017 we had produced 8.2 trillion kilograms of plastics since the early 1950s, which equals the weight of 1 billion elephants or 25,000 Empire State Buildings. Nearly four-fifths of all that plastic is now in landfills or the natural environment, according to a study

No place on Earth has been left uncontaminated by plastic waste, which now permeates everything from the highest peaks of mountains down to the deepest recesses of the seas. Much of it is in the shape of microplastics, which are largely invisible to the eye but can wreak havoc with ecosystems.

Now comes more bad news: plastic pollution in the oceans could be even worse than previously thought, according to a new study published in the journal Scientific Reports. That is because more microplastics accumulate at depths from 200m to 600m than on the surface. This means that much of plastic waste, the authors write, “extends much further and more extensively into the waters, sediments, and animal communities of the deep sea” than hitherto assumed.

At these depth, the scientists found, microplastic concentrations amount to between 12 and 15 particles per cubic meter, which equals and even supersedes the amount in the Great Pacific Garbage Patch, the greatest accumulation of our plastic waste in the ocean that contains more than 1.8 trillion pieces of floating plastic and microplastic debris.

The researchers posit that microplastics, which normally float on the surface, make their way down towards the depths of the sea through the guts of small marine animals like larvaceans and red crabs that ingest tiny plastic particles by mistaking them for plankton, their main food source.

“Examination of two abundant particle feeders in this ecosystem, pelagic red crabs (Pleuroncodes planipes) and giant larvaceans (Bathochordaeus stygius), showed that microplastic particles readily flow from the environment into coupled water column and seafloor food webs,” they explain. “Our findings suggest,” they add, “that one of the largest and currently underappreciated reservoirs of marine microplastics may be contained within the water column and animal communities of the deep sea.”

Their results prove that a large pool of marine microplastics likely exists within the deep-sea water column. “As plastic waste generation is predicted to continue to grow for the rest of this century,” they write, “large-scale conservation and mitigation efforts must consider the enormous spatial (both horizontal, and vertical) and ecological scale of the problem that these new findings reveal.”