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