What are the ecological problems of the oceans associated with?

It would probably be correct to say that the main problem due to which the seas and oceans are polluted is the human factor. So, people pollute the rivers, but the rivers carry garbage into the ocean, everything is simple here. It should be understood that even a small candy wrapper or a cigarette butt is already a big harm, but imagine this on a planetary scale. But the world industry pollutes the ocean very strongly, thanks to the work of which tens of thousands of tons of garbage and various trash appear in the ocean.