The plastic that pollutes the seas is an important cause of death among the animals that eat it attracted by the smell. Plastic fragments also become the home and vehicle of a multitude of bacterial colonies, some potentially dangerous to health.
Size matters
How big does a piece of plastic have to be for it to be ingested by an animal? In a recent study, researchers examined the intestinal contents of over 2,000 animals of various species to predict the size of a plastic object an animal can eat based on its body length.[1]
They estimated that the largest piece of plastic that an animal can eat is about 5% (one-twentieth) the size of the animal.
It turns out that unfortunately no animal is safe from this threat as the plastics that spill into the seas have a wide variety of shapes and sizes.
Smell of junk…food
Among the animals most at risk of swallowing plastic, there are certainly sea turtles. Why? The smell of plastic, especially plastic used as packaging, is an irresistible attraction for them, since they mistake it for food.[2]
Tourists and holidaymakers, seaside and not, remember to dispose of the waste in the correct way so as not to contribute to this sad count.
Dangerous colonies
However, plastic isn’t just a threat to hungry animals. It is estimated that there are at least 5 trillion pieces of plastic in the oceans. We have already seen (read here) that over time discarded plastics degrade into small particles (microplastics) less than 5 mm long.
A new study now shows us that marine microbial communities are able to colonize these microplastics.[3] The microplastics can now act as a vehicle for toxic and pathogenic organisms: they are dragged from the coasts to open oceans (and vice versa) through currents (read here), to be swallowed by animals or to sink and affect organisms on the ocean floor.
All these reasons lead us to find timely solutions to the current problem of plastics in the seas. Aware that more than 80% of the plastics in the oceans are released from rivers, River Cleaning is a project ready to be implemented and installed to stop this wave of death.
[1] Ifan B. Jâms, Fredric M. Windsor, Thomas Poudevigne-Durance, Steve J. Ormerod, Isabelle Durance. Estimating the size distribution of plastics ingested by animals. Nature Communications, 2020; 11 (1) DOI: 10.1038/s41467-020-15406-6
[2] Joseph B. Pfaller, Kayla M. Goforth, Michael A. Gil, Matthew S. Savoca, Kenneth J. Lohmann. Odors from marine plastic debris elicit foraging behavior in sea turtles. Current Biology, 2020; 30 (5): R213 DOI: 10.1016/j.cub.2020.01.071
[3] Joseph Kassandra L. Dudek, Bianca N. Cruz, Beth Polidoro, Susanne Neuer. Microbial colonization of microplastics in the Caribbean Sea. Limnology and Oceanography Letters, 2020; 5 DOI: 10.1002/lol2.10141
