Tag Archives: sea pollution

When Life Colonizes Plastic: the Deep Sea Wonder

The ocean deep, where pressure is high, light absent and nutrients scarce, is often seen as a desert. But, as with other deserts, it has oases. Hydrothermal vents, methane-gas seeps and whale corpses are hot spots for marine wildlife.  These natural loci of biodiversity are now being joined by unnatural ones made of plastic. Researchers obtained 33 objects from the deep sea in the South China Sea. Most were bags, bottles and food wrappers, but they picked up some derelict fishing ropes and traps as well…

These objects were teeming with life. When the researchers examined their finds in a laboratory, they found nearly 1,200 individual organisms representing 49 species of crustaceans, corals, echinoderms, flatworms, molluscs, polychaete worms and fungi. They also discovered evidence that some of these species were breeding. There were egg capsules from four different types of snail, and a cocoon from a flatworm known for parasitising crustaceans. This result suggests that accumulations of plastic are, indeed, benthic oases… As to why organisms colonise the objects in these accumulations, the short answer is, “because they are there”.

Excerpts from Marine Ecology: Deep-ocean plastic is a haven for life, Economist, Feb. 6, 2021

Forever Dead Products

In a paper published in 2107 in Science Advances, Roland Geyer of the University of California, Santa Barbara, and his colleagues put the cumulative amount of solid plastic waste produced since the 1950s that has not been burned or recycled at 4.9bn tonnes. It could all have been dumped in a landfill 70 metres deep and 57 square kilometres in area—that is to say, the size of Manhattan

If only it had all remained on land, or even washed up on beaches, where it could be collected. A bigger environmental worry is that much plastic has ended up in the ocean, where, dispersed by currents, the stuff becomes virtually irretrievable, especially once it has fragmented into microplastics. Computer models suggest that seas hold as many as 51trn microplastic particles. Some are the product of larger pieces breaking apart; others, like microbeads added to toothpaste or face scrubs, were designed to be tiny….

Even if the flow of plastic into the sea, totalling perhaps 10m tonnes a year, was instantly stanched, huge quantities would remain. And the flow will not stop. Most of the plastic in the ocean comes not from tidy Europe and America, but from countries in fast-developing East Asia, where waste-collection systems are flawed or non-existent. In October 2017 scientists at the Helmholtz Centre for Environmental Research, in Germany, found that ten rivers—two in Africa and the rest in Asia—discharge 90% of all plastic marine debris. The Yangtze alone carries 1.5m tonnes a year

Trucost, a research arm of Standard & Poor’s, a financial-information provider, has estimated that marine litter costs $13bn a year, mainly through its adverse effect on fisheries, tourism and biodiversity. It puts the overall social and environmental cost of plastic pollution at $139bn a year. Of that half arises from the climate effects of greenhouse-gas emissions linked to producing and transporting plastic. Another third comes from the impact of associated air, water and land pollution on health, crops and the environment, plus the cost of waste disposal.

Exerpts from:  Plastic Pollution: Too Much of a Good Thing, Economist, Mar. 3, 2018, at 51

Production, use, and fate of all plastics ever made (R. Greyer et al., 2017)