I heard about that too, due to the ocean currents being conducive to the spread of larvae I believe. Essentially, the entire ocean is a giant whirlpool, at least, all those that are linked one way or another. Crucially, there is a strata which has similar conditions, stretching across the planet, most fascinating indeed. Its quite counter-intuitive, but I guess once you get that far down, it all seems the same anyhow...
