Managed to do a second ocean litter survey during the stay in Tobal (Aur atoll). Tobal only imports a very limited amount of stuff and only 200 people living there at the lagoon side so the litter from the ocean side (windward direction) is entirely from abroad.
The results of this beach sample are interesting because they allow to identify the amount of domestic litter found during the previous survey on Bok En, Majuro atoll. Assuming both places get hit by the same amount of ocean litter from abroad (both places have the same orientation to the main wind direction and are not covered by other islands), the litter that was found in Majuro even more or in addition compared to Aur can be assumed to be domestic.
The survey on Aur has a few interesting aspects. For example there is one type of plastic bottle that was found 36 times on this 20 m stretch of beach. Almost 2 per meter! These bottles were found all over the shorelines of the islands of Aur! Eventually I could find one of these bottles with a label on somewhere else and trace it back to a Taiwanese brand mainly selling in China. I suspect the Chinese tuna fishing ships use them and just toss them over board.
There will be another survey like this on Likiep atoll and eventually a proper report about the results so stay tuned!