World's oceans now contain 5 trillion pieces of plastic waste created by humans

(NaturalNews) One of the most unsightly traces of human existence is trash, particularly when it's recklessly littered all over our beautiful, green landscape. Unfortunately, this type of pollution isn't limited to just the land. The results of a new major study on the ocean reveal some shocking statistics, concerning enough to make us all reconsider our plastic waste consumption.

An estimated 5 trillion pieces of plastic, weighing more than 250,000 tons, are floating around the world's oceans, negatively impacting marine life, according to research led by Marcus Eriksen, and published in the December 10 PLOS ONE journal.

Until recently, information regarding the abundance and weight of floating plastics in the Southern Hemisphere and remote regions was unknown. However, 24 expeditions completed between 2007 and 2013 have changed that, creating awareness and shedding new light on this important environmental issue.

Plastic pollution in the ocean dependent on population density, maritime activity and watershed outfalls

Scientists collected data across all five subtropical gyres (North Pacific, North Atlantic, South Pacific, South Atlantic, Indian Ocean), coastal Australia, the Bay of Bengal and the Mediterranean Sea, "conducting surface net tows... and visual survey transects of large plastic debris," in a total of 1,571 locations.

Using existing and new data, researchers were able to develop an oceanographic model simulating the amount and distribution of plastics.

Based on the data, scientists were able to estimate the weight densities of scattered plastics. According to the oceanographic model, the amount of plastic pollution in the ocean depends on three variables: watershed outfalls, population density and maritime activity.

Plastic debris was categorized according to size, including small, large, mesoplastic and macroplastic. In order to collect the debris, scientists towed 0.33 mm nets along the sea surface for 15 to 60 minutes outside of the vessel's wake, making sure to avoid "downwelling" of debris. Natural debris was sorted out, and the remaining man-made debris was categorized according to size and then weighed both individually and together.

Some researchers were tasked with scanning the ocean up to 20 meters out from the side of a vessel, looking for large-sized debris. Their observations were broken into nine categories, with four of them being fishing-related debris: buoy, line, net and other fishing gear. The other five categories included bucket, bottle, foamed polystyrene, bag/film and miscellaneous plastics.

Since the data was obtained visually, researchers used similar debris items collected from shorelines in northern-central Chile, South Africa, America's North Atlantic coast, and the Hawaiian Archipelago to determine the average weights of items in the nine categories.

Plastic pollution persistent even in regions with fewer humans

The findings allowed scientists to gain a better understanding of the amount of pollution, the most commonly occurring size of debris and the way that plastic changes within the ocean, breaking down into smaller pieces and circulating around the globe due to prevailing winds and surface currents.

Scientists were surprised to learn that the amount of plastic present in the southern hemisphere was similar to that found in the northern hemisphere oceans, an unexpected finding considering that the inputs are much greater in the northern than in the southern hemisphere.

Researchers now believe that ocean currents are redistributing plastics more easily than previously thought. "What we are witnessing in the global ocean is a growing threat of toxin-laden microplastics cycling through the entire marine ecosystem," said Eriksen, the study's lead author.

Even the plastic industry recognizes the problem, agreeing that their products don't belong in the ocean. "Even after plastics have fulfilled their initial purpose, these materials should be treated as valuable resources and recycled whenever possible or recovered for their energy value when they cannot," according to a statement by the American Chemistry Council.

Sources:

http://www.washingtonpost.com

http://www.plosone.org

http://www.onegreenplanet.org

http://science.naturalnews.com