Once again, plastic has proven to be ubiquitous in the ocean. Diving to the bottom of the Mariana Trench, which allegedly reached 35,849 feet, Dallas businessman Victor Vescovo claimed to have found a plastic bag. This is not even the first time: this is the third time that plastic has been found in the deepest part of the ocean.
Vescovo dived in a bathyscaphe on April 28 as part of his “Five Depths” expedition, which includes a trip to the deepest parts of the earth’s oceans. During Vescovo’s four hours at the bottom of the Mariana Trench, he observed several types of marine life, one of which may be a new species – a plastic bag and candy wrappers.
Few have reached such extreme depths. Swiss engineer Jacques Piccard and US Navy Lieutenant Don Walsh were the first in 1960. National Geographic explorer and filmmaker James Cameron sank to the bottom of the ocean in 2012. Cameron recorded a dive to a depth of 35,787 feet, just short of the 62 feet that Vescovo claimed to have reached.
Unlike humans, plastic falls off easily. Earlier this year, a study sampled amphipods from six deep-sea trenches, including the Marianas, and found that all of them had ingested microplastics.
A study published in October 2018 documented the deepest known plastic — a fragile shopping bag — found 36,000 feet deep in the Mariana Trench. Scientists discovered it by examining the Deep Sea Debris Database, which consists of photos and videos of 5,010 dives over the past 30 years.
Of the sorted waste recorded in the database, plastic is the most common, with plastic bags in particular being the largest source of plastic waste. Other debris was from materials such as rubber, metal, wood and fabric.
Up to 89% of the plastics in the study were single-use, those that are used once and then thrown away, such as plastic water bottles or disposable tableware.
The Mariana Trench is not a dark lifeless pit, it has many inhabitants. The NOAA Okeanos Explorer explored the region’s depths in 2016 and discovered a variety of life forms, including species such as corals, jellyfish and octopuses. The 2018 study also found that 17 percent of the plastic images recorded in the database showed some kind of interaction with marine life, such as animals getting tangled in debris.
Single-use plastic is ubiquitous and can take hundreds of years or more to decompose in the wild. According to a February 2017 study, pollution levels in the Mariana Trench are higher in some areas than some of China’s most polluted rivers. The authors of the study suggest that the chemical contaminants in the trenches may come in part from plastic in the water column.
Tubeworms (red), eel and jockey crab find a place near a hydrothermal vent. (Learn about the strange fauna of the Pacific’s deepest hydrothermal vents.)
While plastic can enter the ocean directly, such as debris blown off beaches or dumped from boats, a study published in 2017 found that most of it enters the ocean from 10 rivers that flow through human settlements.
Abandoned fishing gear is also a major source of plastic pollution, with a study published in March 2018 showing that the material makes up most of the Texas-sized Great Pacific Garbage Patch floating between Hawaii and California.
While there is clearly a lot more plastic in the ocean than there is in a single plastic bag, the item has now evolved from an indifferent metaphor for the wind to an example of how much humans impact the planet.
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Post time: Aug-30-2022