We can't continue to dump it in the ocean. And until that's done the world's oceans will continue to deteriorate. We have to bite the bullet, spend the money and clean up our own mess. It's not really a problem. The rigs become artificial reefs and increase fish populations, they become self contained ecosystems.
Oil spills cause short-term damage and marine creature kills.
But recovery is rapid and not long-lasting in its effects, as compared with homogenised pollution which goes over the seabed and throughout the water column. Oil spills are a surface problem. Even so, because they're the result of human error, we should increase the penalties to prevent them happening. Tankers - I don't know what you can do about them. They go from jurisdiction to jurisdiction and short of building double-hulled ships I can't see a solution.