Ok, but...
It's a strong message, but without explaining the "cause" you've neutered the "effect". Follow me here...
I live in the middle of a land-locked city. How does my unrecycled plastic end up in the ocean? You need to explain that. You need to explain that by tossing plastic bottles in the street, even in a land-locked city, rainwater can wash them into sewer systems, then into rivers which lead to the ocean.
Also, you could explain the economic implications of plastic recycling. It takes far more energy to create a new plastic bottle than it does to recycle an old one. Better yet, it takes more energy to create a new plastic bottle than it does to re-use an old one. It takes far more time, energy, money (resources) to produce and ship bottled water than it does to simply install a water filter on your faucet (something people are starting to realize, especially since bottled water really doesn't have to follow any kind of standards for purity.)
There's more to this than just showing some fish in the ocean with a coke bottle ringer around it's neck. I understand the emotional impact you're going for, but unless you follow and show the viewer the chain of precedence on how it's THEIR fault or why THEY should care, some folks will just blow this off as an emotional plea with little logic supporting it.