‘But probably, most of the impacts taking place due to plastic pollution in the oceans are not yet known’
FRISCO — Humankind’s out-of-sight, out-of-mind attitude about garbage is slowly but surely turning the world’s oceans into a soup full of microscopic plastic particles that are probably passing into the marine food chain, Spanish scientists said this week, describing their findings from a nine-month research cruise around the world.
“Ocean currents carry plastic objects which split into smaller and smaller fragments due to solar radiation,” said Andrés Cózar, aresearcher with the University of Cadiz. “Those little pieces of plastic, known as microplastics, can last hundreds of years and were detected in 88 percent of the ocean surface sampled during the 2010 Malaspina Expedition,” Cózar said.
According to the study authors, the results obtained by the Malaspina Expedition show that the problem of plastic waste pollution has a global character. The major residues found are polyethylene and polypropylene, polymers used in the manufacture of everyday products like bags, food and beverage containers, kitchen utensils and toys, among others.
“These microplastics have an influence on the behavior and the food chain of marine organisms,” Cózar said. “On one hand, the tiny plastic fragments often accumulate contaminants that, if swallowed, can be passed to organisms during digestion; without forgetting the gastrointestinal obstructions, which are another of the most common problems with this type of waste. On the other hand, the abundance of floating plastic fragments allows many small organisms to sail on them and colonize places they could not access to previously. But probably, most of the impacts taking place due to plastic pollution in the oceans are not yet known.”
“Our results show that the high concentration of plastic is not a unique feature of the North Pacific, but occurs in each of the subtropical gyres,” said Carlos Duarte, coordinator of the Malaspina Expedition. “Only a global expedition, such as the Malaspina Expedition, could achieve these results and evaluate the overall abundance of plastic pollution. The good news is that abundance is much lower than expected, but the pending challenge is to figure out where the rest of plastics entering the ocean is.”
The Malaspina Expedition
The Malaspina Circumnavigation Expedition 2010, a project led by CSIC that includes more than 400 researchers from around the world, started in December 15th 2010 with the departure of the Hespérides oceanographic research vessel from the port of Cadiz. On board of this ship belonging to the Spanish Armada, and the Sarmiento de Gamboa ship belonging to the CSIC, researchers studied for nine months (seven aboard the Hespérides and two aboard the Sarmiento) the impact of the global change on the ocean ecosystem and explored its biodiversity.
Scientists took nearly 200,000 water, plankton, atmosphere particles and gases samples in 313 points of the Indian, Pacific and Atlantic Oceans at depths of up to 6,000 meters. On board, they measured the temperature and salinity, the surface properties, the acoustics of the marine currents, the concentration of oxygen and carbon dioxide in the ocean and in the atmosphere, and the scope of the sunlight, among other parameters.