Are you asking me what is the problem with 100+ tons of reactor-contaminated groundwater effluent entering the sea on a daily basis? On the surface this seems like a weak attempt at a strawman, please clarify.

edit: s/irradiated/reactor-contaminated/

Yes, I'm asking that. Because all sea water is irradiated anyway, the effects depend on the amount of radiation in the water. So, what problems is this water entering the sea causing?

My understanding is not all isotopes are equally hazardous. The stuff coming with the reactor-contaminated water is particularly harmful to the marine environment and people of Japan, and not normally present at such levels in the surrounding waters.

The half-life as I understand it is relatively short for the especially harmful stuff, but that's not so helpful if leaks are ongoing.

Yes, he is, and I am as well. First of all, irradiated doesn't mean radioactive. Most food in the US is irradiated for health purposes before sale at grocery stores.

How is it contaminated? What's the distribution of contaminants? Do they actually have a significant effect?