¿How does ocean pollution affect every nation around the world?

Pollution does not affect a nation specifically, it affect all the world and obviouslly us.

And about the ocean, it is affect because some nations fish and their economy is good because of it.

As an example of it is Peru, here in Peru we have a great variety of fishes and people fish them and sold it, but pollution sometimes make the weather change, so the ocean get hotter or more cold what I mean is that the temperature of the ocean change and the fishes die.

Another example as you said is Panama that is just like Peru.