The industry is required to report debris washed up on shore, but not debris floating in the ocean. They make a great fuss over their periodic onshore cleanups, and while any attempt to remove plastic pollution is welcome, it manages only a proportion of the results, while not dealing at all with its source. And it doesn't do anything about microplastics.
Moving to self-contained land based production would largely eliminate marine pollution at source.
Report marine debris whenever and where ever you find it.
Here is a small sample of marine debris from the fish pens: