As companies race to expand renewable energy and the batteries to store it, finding sufficient amounts of rare earth metals to build the technology is no easy feat. That's leading mining companies to take a closer look at a largely unexplored frontier – the deep ocean seabed. A wealth of these metals can be found in manganese nodules that look like cobblestones scattered across wide areas of deep ocean seabed. But the fragile ecosystems deep in the oceans are little understood, and the mining codes to sustainably mine these areas are in their infancy. A fierce debate is now playing…