Boris Worm says that's not surprising given how little we know about the abyssal plain.

NPR: Down Deep, An Unexpected Fish Boom

Marine biologist David Black(ph) of the Scripps Institution of Oceanography says the abyssal plain is at once the most common and least studied habitat in the world.

NPR: Down Deep, An Unexpected Fish Boom

If Iraq were to fall out of the sky onto a random part of the earth, odds are good that it would plunk into the ocean, sink for at least two miles and then settle into a seemingly endless mudflat called the abyssal plain.

NPR: Down Deep, An Unexpected Fish Boom