Dark Region of Ocean May Shed Light on Climate Change and Other Issues

"The tiny fish known as the bristlemouth is part of a detective story that bears on everything from feeding the planet and monitoring ocean health to learning how to better predict climate change.

The case centers on the ocean’s twilight zone — a dim region that extends from just below sunlit waters down to a depth of 1,000 meters, or 3,300 feet. Its darkness is broken up only by the rays that filter down on bright days. That weak light, even at its best, is insufficient to support photosynthesis and microscopic plants. So the zone cannot empower an oceanic food chain from scratch.

Given that knowledge, it was long suggested that this region — known as the mesopelagic zone, from the Greek words for “middle” and “sea” — was relatively empty. Instead, it churns with life."

William J. Broad reports for the New York Times June 29, 2015.