Why would any paper bag need to be dumped in the ocean? Are U.S. plastic bags and single use takeout containers ending up in the ocean in significant quantities

Why would any paper bag need to be dumped in the ocean? Are U.S. plastic bags and single use takeout containers ending up in the ocean in significant quantities? If so, what municipality is dumping them in and why aren't we stopping them? We have plenty of space (absent NIMBY zoning issues) and the capability to build ever safer landfills.