Originally Posted by Frozen_Feet
In this case, "nothing of value" could mean species that would still remain abundant (and potentially be more vital) elsewhere, or nothing, period, as is the case with rocky portions of certain deserts.
Also, don't go discounting solar power at sea. There are working plans for stations at sea, which would capture worthwhile amount of energy while not severely impacting planktons you mentioned. (Well, not any more severely than current travel by oceans, but that's a can of worms on its own.) Plus, plankton and seaweed farms, which would increase the conversion rate while also giving us fuel and/or food.
Now there is a possibility.
I like the idea of using algae based biofuels because, unlike soybeans and corn, much more of the organism is creating the hydrocarbons. And unlike hydrogen as an energy battary, even if we can get around the volume and storability problems we already have over a hundred years of infrastructure devoted to transporting and using petrochemicals.