Marine Litter in Indonesia &#8211; &#160;Tracking macro-plastic from river mouths with Argos buoys and modelling
Authors: Fauny Olivia , Lucas Marc , Dufau Claire , Voisin Jean-Baptiste 
Published: March 2021

&lt;p&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;The Indonesian archipelago is rated globally the second contributor to marine plastic litter pollution. This has driven the government in recent years to step up its efforts to combat plastic pollution, on land, in rivers and in the ocean. Indeed, although most of the plastic is disposed on land, lack of a systematic collection and processing network means that it often ends up rivers and ultimately into the seas. Heavy precipitation events during the Monsoon season exacerbate the problem by transporting massive amounts of plastic into rivers and hence into the coastal seas. Amongst the more recent initiative to combat the plastic litter issue,&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;and&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;with funding from&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;the World Bank&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;,&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;the&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;government&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;&amp;#160;of I&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;ndonesia has set up a&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;program&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;to track the movement of plastic through a hybrid observation &amp; model approach and to determine the location of accumulation areas if any. The project deployed and tracked number of&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;20&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;Argos drifters over a year and set up a series of drift model simulation. As the project focuses on macro plastic,&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;several types of macro-waste drifts have been modelized depending on their buoyancy&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;b&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;y varying wind coefficient&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;. Three river mouths were studied,&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;located downstream from major populated areas.&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;Results&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;&amp;#160;show that the dispersion and trajectory of particles vary depending on the source river, time of the year and&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;meteoceanic&lt;/span&gt;&lt;/span&gt;&lt;span xml:lang=&quot;EN-GB&quot; data-contrast=&quot;auto&quot;&gt;&lt;span&gt;&amp;#160;conditions. For each river, accumulation areas were identified, concentring 38% to 90% of particles and all located on shore.&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;#160;&lt;/span&gt;&lt;/p&gt;