Should We Mine the Ocean?

Over 70 percent of the Earth is covered in water, leaving just 30 percent solid land for the six billion humans and countless plants, animals and insects to share.  For the past five thousand years, most of the metals and raw materials that we've collected has been from the land.  Gold, silver, iron, zinc, nickel ... all of these have been found in relative abundance in some parts of the world, and all on land.

With the existing quantities found on only 30 percent of the globe, it would only make sense that in the ocean depths there would be more.  However, I am concerned that in exchange for these base metals, we could seriously damage a little-understood ecosystem on the bottom of the oceans.

Nautilus Minerals, a Vancouver-based mining company with a focus on offshore strip-mining, is currently exploring the potential for gold and copper deposits off the coast of Papua New Guinea.  Their Solwara Project is currently only in the "exploratory stages", meaning that the project is still being investigated, and a few core samples will have been collected while the topography of the region is better mapped and studied.  But I'm wondering if we (as a species) should be collecting our resources from the oceans.

Already we've devastated fish stocks, introduced high levels of pollution to the waters, and interfered with the wildlife enough that their world will never be the same.  Should we now strip mine land that we cannot easily see in search of minerals that can be used in manufactured goods?

I really like the fact that Nautilus Minerals is paying attention to the underwater environment as best it can, and even brought several marine biologists from respected institutions such as the University of Toronto and James Cook University, but I fear that despite everyones best intentions, the fragile world down below could be damaged in ways we never envisioned.

The primary location of interest includes several areas rich in hydrothermal vents.  These areas are rich in sulfur and other minerals, and they also contain some of the least understood plant and animal lifeforms on the planet.  Some of the creatures that call this area home live in waters exceeding 350 degrees celcius.  On top of that, the top layer of the ocean floor is typically very nutrient-poor.  Strip mining the land would mean pulling that soil up to the surface, where it would then be sorted.  Minerals of worth would be kept, while the remaining soil and muck would be sent back to the ocean.  With the soil effectively "tilled", quite a bit of nutrient-rich dirt woud be sent down.  This could cause huge amounts of algae-bloom to occur, which would drastically change the environment for local fish stocks.

Mining the ocean in international waters is highly regulated by the UN, but mining in territorial waters is only regulated by the country pertaining to that area.  To what level will these countries go in order to preserve the oceans?  Will some poorer countries even consider the potential ecological damage that could be caused if a mining organization arrives at their door and offers millions for the rights to mine their oceans?

Nautilus Minerals, and other companies like them, are exploring ways to both collect the minerals that are in high demand while also preserving these underwanter ecosystems as best as possible.  My biggest fear is that despite our best intentions, we're going to make a mess that could have very broad unforseen circumstances.