Twenty-four trillion pieces of microplastics in the ocean and counting


Date:
October 27, 2021
Source:
Kyushu University
Summary:
Based on a total of 8,218 pelagic microplastic samples from
the world's oceans collected between 2000 and 2019, a team
of scientists has developed a publicly available dataset for
assessing the abundance of microplastics and their long-term trend
in the world's upper oceans. The team found 24.4 trillion pieces
(82,000--578,000 tons) of microplastics in the world's oceans,
but the actual amount is likely to be much greater.



FULL STORY ==========================================================================
In the Age of Exploration, scientists sailed across the oceans to
discover indigenous flora and fauna in faraway lands. Today, scientists
are sailing the world's open seas equipped with a tow net and flowmeter
to sample microplastics.


==========================================================================
Now, a global team of oceanographers led by Kyushu University researchers
has calibrated and processed data from these expeditions to build a
publicly available dataset for more accurately assessing the abundance
of microplastics -- and their long-term trends -- in the world's oceans.

"Although the observation of microplastics dates back to the 1970s, standardized data spanning the globe is still limited," explains Atsuhiko Isobe, professor at Kyushu University's Research Institute for Applied Mechanics and leader of the study.

"Our dataset provides realistic amounts of microplastics in the wild to
help researchers trying to assess the true impact they are having on
aquatic organisms and the environment." Categorized as small pieces
of degraded plastic less than five millimeters in size, microplastics
can travel thousands of miles in the open sea and, depending on their degradation, remain at various depths of the ocean surface.

While numerous surveys in the last 50 years have set out to measure the
amount of microplastics in the ocean, the combining and archiving of
data has been slow and faces many challenges related to differences in collection methods and conditions, such as ocean turbulence, and counting
and analysis protocols.



==========================================================================
To create the new dataset, which was published in the journal
Microplastics and Nanoplastics, the researchers collected, calibrated,
and gridded data from a total of 8,218 pelagic microplastic samples
taken from oceans around the world between 2000 and 2019.

"We collected published and unpublished data on microplastic distribution
from around the world and calibrated to account for differences such as in collection method and wave height to create standardized, state-of-the-art
2D maps of microplastic abundance," explains Isobe.

The team estimates there are 24.4 trillion pieces of microplastics in the world's upper oceans, with a combined weight of 82,000 to 578,000 tons --
or the equivalent of roughly 30 billion 500-ml plastic water bottles.

"While this work improves our grasp of the actual situation, the total
amount of microplastics is still likely to be much greater since this is
just what we can estimate on the surface," states Isobe. "For us to get a clearer picture, we must develop 3D maps probing the depths of the oceans
and continue to fill the gaps within our dataset." One gap is the lack
of microplastic data for the Indian Ocean and the seas around Southeast
Asia, including the South China Sea. Moreover, data is missing for microplastics less than 300 micrometers in size or even on the nano scale.

This is due to the lack of field survey protocols for such plastics and limitations in equipment and the mesh size of nets used in the field.

Isobe hopes that future surveys will continue to fill in these gaps
using common protocols to facilitate data sharing.

"Though we are making progress, we still have much to learn to get a
complete picture of the fate of plastic debris and the effect it is
having on the environment," concludes Isobe.

========================================================================== Story Source: Materials provided by Kyushu_University. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Atsuhiko Isobe, Takafumi Azuma, Muhammad Reza Cordova, Andre's
Co'zar,
Francois Galgani, Ryuichi Hagita, La Daana Kanhai, Keiri Imai,
Shinsuke Iwasaki, Shin'ichro Kako, Nikolai Kozlovskii, Amy
L. Lusher, Sherri A.

Mason, Yutaka Michida, Takahisa Mituhasi, Yasuhiro Morii, Tohru
Mukai, Anna Popova, Kenichi Shimizu, Tadashi Tokai, Keiichi
Uchida, Mitsuharu Yagi, Weiwei Zhang. A multilevel dataset
of microplastic abundance in the world's upper ocean and the
Laurentian Great Lakes. Microplastics and Nanoplastics, 2021; 1
(1) DOI: 10.1186/s43591-021-00013-z ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/10/211027122120.htm

--- up 7 weeks, 6 days, 8 hours, 25 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)