No, because this will blend into the existing background radiation already present in the ocean.

I'd worry a lot more about other pollutants we've been dumping for decades. You get more radioactivity exposure from the world's active coal plants than a bunch of Fukushimas.

Hard to know without more info. It likely depends on the rate with which they release it and the currents, i.e. how the radioactive water dilutes with the ocean. What should matter for the fish consumption there should be the local concentration.