450 tons of water is a drop compared to the vast amount of water in the pacific, so feel free to keep on eating fish. As a sidenote: I've recently seen an increase in people submitting overhyped/scaremongering/dodgy as hell posts like OP's, hopefully the mods step in at some point.
You may accuse others of scaremongering, but I call you apathetic and you're trying to spread apathy to others. Why even bother commenting? Oh, I accidentally voted you up, and I want that vote back.
Trying to spread apathy? That's a new one. I'm just trying to stop the spread of unreasonable hyperbole on HN which used to be much more skeptical towards links like this. There are enough things to get riled up about (the NSA for starters), no need to add lies like in OP's link to that.
Here's a post to downvote, feel free.