Well, he has basically tossed ~2,000 plastic bottles into the ocean that have not been recovered (yet). That's not a small number of bottles.
It seems cool, until you try to consider the externalities he has casually handed off.
Now, if he had used glass bottles, it would probably work out a little better. Though it still takes a long time, glass can be broken down by the ocean and incorporated into sand, which is part glass anyways.
2000 seems like a large number, until you realize that you have to compare it to the mindbogglingly large number that is the surface area of the ocean. He may as well pissed in it for all the harm he did.
Not to detract from the man's project (which I think is cool), but every little piece of garbage in the ocean does add up. Oceanographers have mapped garbage patches in each of the oceans, e.g.:
The Great Pacific Garbage Patch (http://en.wikipedia.org/wiki/Great_Pacific_Garbage_Patch) is a real problem. Estimates put its size between 270,000 sq miles 5,800,000 sq miles of floating trash, most of which is plastic. It pollutes the water, kills marine life, and introduces toxins into the food chain which can end up on your dinner plate.
Saying 2000 bottles is not a big deal in the grand scheme of things is shortsighted and irresponsible. Millions of tons of garbage doesn't appear in the ocean for no reason. It exists because everyone thinks to themselves "hey, the ocean is a really big place... what harm does a few bottles really have?" The problem is only getting worse, and after all.. we haven't had plastics for that long.
There's no justification for throwing plastic bottles in the ocean. It doesn't improve the environment in any way, but it currently negatively affects hundreds of species.
A one-off deposit of 2000 bottles has a negligible impact on the Patch. To tackle that, we need to fundamentally re-think a lot of the ways we conduct ourselves.
Perhaps a better, and more rational argument, is that we should care more about the oil being burned around the world, and not less about the amount of trash being thrown into the ocean.
What matters is the comparison of the 2k bottles to the rest of his garbage production, and his overall garbage production to the average.
If they represent only a few percent of his annual plastic-in-ocean contribution, it would be silly to worry about them while ignoring all that other stuff.
I certainly agree that it meets the definition, and this wouldn't work out well for a million people to do, but fortunately a million people don't do it.
Then there will be a mere 0.0000000027 bottles per square meter of the ocean. I'll leave working the numbers for cubic meters up to you, but sufficed to say it will hardly matter.
And what harm will these bottles cause, to anything but human aesthetic? Little to none.
The argument that the ocean is so vast that you can dump anything in it without ill effects was proven wrong decades ago. That's why there are laws against it. If you looked, you can find hundreds of sources to back this up.
I think this was a cool experiment. But people and animals live in these environments, and certainly matters to them when someone tosses non-degradable material in their backyard. How would you like it if people started dumping plastic garbage in your backyard? What about in your house? Surely it's only effects your aesthetic enjoyment, so it doesn't matter right?
Fifteen years ago there was no "Facebook, Twitter, Google+, Match.com or even GrubWithUs"... I was barely able to dial up on the nascent and overpriced Wanadoo at that time.
What is so special about plastic? In thousands of years there will be geological layers filled with the stuff, fundamentally no different than all the rock layers and fossil layers laid down at any other time.
Plastic decomposes in "only" 400-500 years. So while we might have a problem with it now, it's all gone in a fraction of a second, when seen in a geological timeframe.
I'd love to see a map of all the responses; I suspect it would have quite an interesting geographical distribution.
The sad thing: someone will read this and go after the guy for littering rather than saying "awesome!".