Spanish treasure .. or Native American treasure?

This deep-water shipwreck exploration company, Odyssey Marine Exploration, finds a sunken ship filled with millions of gold and silver coins. Spain argues that the ship, the Spanish naval vessel Nuestra Senora de las Mercedes and its contents belongs to them, and a U.S. judge has agreed.

I know international law says Spain owns the vessel. But the gold? Wasn’t that looted from the goldmines of the Incan and Mayan people? Shouldn’t their decendants have a stronger claim?

And what about the British, which sunk the Mercedes in 1804? Since it was their cannons made a reef out of the Mercedes wouldn’t they also have a claim?

It seems to me that all of this is simply a bunch of thieves fighting over loot none of them legally own. Perhaps it belongs beneath the waves after all.