The Malaspina Expedition , in charge of the Higher Council for Scientific Research (CSIC), has found five large accumulations of plastic waste in the open sea , which coincide with the five great turns of circulation of oceanic surface water.
Aside from the now infamous accumulation of plastic trash in the North Pacific , there are similar expanses of plastic trash in the central North Atlantic, the South Pacific, the South Atlantic, and the Indian Ocean . However, according to a study from this Expedition, surface waters may not be the final destination for plastic waste as large amounts of microplastics appear to be moving up the marine food chain and to the ocean floor.
The results of the work have been published in the journal Proceedings of the National Academy of Sciences (PNAS). “Ocean currents carry plastic objects, which break apart into smaller and smaller pieces due to solar radiation. Those small pieces known as microplastics that were detected in 88% of the oceanic surface sampled during the Malaspina Expedition 2010 can last hundreds of years ”, explains researcher Andrés Cózar, from the University of Cádiz, who has led the research.
According to the results obtained by Spanish researchers, the problem of plastic waste pollution is global in nature . The main materials found are polyethylene and polypropylene, polymers used in the production of everyday products such as bags, food and drink containers, kitchen utensils and toys.
“ These microplastics influence the behavior and the food chain of marine organisms . On the one hand, the tiny plastic fragments often include contaminants that, if ingested, can pass to animals during digestion. Not forgetting gastrointestinal obstructions, which are another of the most frequent problems with this type of waste.
On the other hand, the abundance of floating plastic fragments allows many small organisms to navigate on them and colonize places that until now they could not access. But, probably, most of the impacts that plastic pollution is causing in the oceans are not yet known ”, adds the researcher.
“The high concentration of plastics is not a unique characteristic of the North Pacific, but it occurs in each of the subtropical gyres,” says CSIC scientist Carlos Duarte, coordinator of the Malaspina Expedition. “Only a global expedition like this could assess global plastic pollution. The good news is that it is less than expected, but the pending challenge is to find out where the rest of the plastics that enter the ocean are ”, concludes Duarte.
The Malaspina 2010 Circumnavigation Expedition, a project led by the CSIC that integrates more than 400 scientists from around the world, started on December 15, 2010 with the departure from the port of Cádiz of the oceanographic research vessel Hespérides. On board this ship of the Spanish Navy and the Sarmiento de Gamboa ship, belonging to the CSIC, the researchers studied for nine months (seven on board the Hespérides and two on board the Sarmiento) the impact of global change on the ocean ecosystem and explored its biodiversity.
The scientists took about 200,000 samples of water, plankton, atmospheric particles and gases at 313 points in the Indian, Pacific and Atlantic oceans with depths of up to 6,000 meters. On board they measured the temperature and salinity, the properties of the surface, the acoustics of the marine currents, the concentration of oxygen and carbon dioxide in the sea and in the atmosphere and the scope of sunlight, among other parameters.
