It has everything to do with it. Next to maybe the atmosphere, the ocean is the best recycling system on this planet. So when something gets dumped in place A it doesn't stay there, ocean currents work their magic and that pollution gets distributed throughout the entire system. Meaning it gets diluted to ppb or less.
I'm no expert, but it wouldn't surprise me if much of that stuff is propaganda or studies being warped to fit someones agenda. I'd just like to see the studies and data these claims are based on. Something doesn't add up. Much the same as how man made global warming is a crock of shit.
You don't think the US, India, and China alone dumping their stuff into the ocean is enough to still fuck up the rest of the world through the oceans and seas it gets passed into? I got no scientific data, but that's a lot of trash over a period of decades.
You're a geologist so you may understand how the destruction of the ozone layer, amongst many other things, contributes to global warming, right? They say with this increase in heat on Earth, the water on this planet increases by one degree (Celsius, or Fahrenheit? I don't know). One degree means the world to the ocean as it allows more bacteria to thrive in the waters and fuck with more marine life. Also, increasing the temperature of the water DECREASES the solubility of oxygen in the water, which further devastates the fish.
That was just heat. UV rays from the sun are carcinogens. You don't think the tons of plastic (BPA, which is a carcinogen to humans and can be found in bottled water) in the ocean is toxic to the fish too? Even if we take out plastic, there are plenty of carcinogenic materials we throw away (batteries) that can find their way into the ocean and into the fish we eat.
I know the ocean is deep. If you stuck Mount Everest at the bottom of the trench, it would still be no where near the surface of the ocean. But the more shallower waters, which are closer to shore, it definitely gets "diluted" but not by as much as you might think. It can be just a mile off the coast, which is enough to affect fish that are just passing by and going to other places, only to be caught and consumed some time later.
Now I'm curious: what do you think the furthest a fish has ever swam from the point at which it was spawned? I mean, for a human to go from Spain to, say, West Russia on foot would take forever and a half and would be pretty tough as well. What about for a fish just off the coast of China? You think it'd make it as far as the West coast of Africa? Or Australia?