"After trash is removed from the Interceptor Barricade using excavators, it is weighed on-site to determine the total catch quantity and passed to local partners and waste management authorities for processing."
One would hope that specifically-contracted partners and authorities wouldn't be engaged in such activities, though Ocean Cleanup's site is ... somewhat vague on this point.
Might make for a useful pointed inquiry, as such gaps and loopholes are a stubbornly pervasive aspect of similar initiatives.
you'll make your progeny exceedingly wealthy beyond even your wildest dreams and for generations to come if you can answer the first question. but you're obviously just being sarcastic given the second, so no, that's not likely what they intend to do with it.
Caption to the first photo in TFA.