The massive concentration in the Philippines is one of the most interesting takeaways here. I ended up poking around for more details on this, and it looks like the causes relate to, among other things, a lack of proper waste disposal and an industry reliance on plastic sachets for food packaging.

Sources: https://www.scmp.com/lifestyle/health/article/2168819/philip...

https://news.mongabay.com/2018/10/plastic-trash-from-the-sac...

https://urban-links.org/insight/turning-the-tide-on-ocean-pl...