Exploring the ocean’s vast twilight zone, teeming with undiscovered life and solutions for climate change

The problem

The ocean’s twilight zone, known to scientists as the mesopelagic or midwater region, sits beyond human sight, about 200 to 1,000 meters beneath the surface. The sun in the twilight zone is barely a glimmer, but the region is teeming with life. In fact, the twilight zone is believed to be home to more than one million new species, and up to 90 percent of the world’s total fish biomass. The world’s largest animal migration takes place here every day. Yet, the region has been largely unexplored.

Big idea

Woods Hole Oceanographic Institution (WHOI) is launching a mission to explore the twilight zone, a globe-spanning ecosystem that is deeply intertwined with the entire marine food web and even Earth’s climate system. The goal is to understand how the extraction of resources from this zone might affect it in ways that could reverberate throughout the ocean and around the world, for centuries to come. Commercial fishing interests are scaling up efforts to harvest the twilight zone, despite our lack of knowledge about the region and its inhabitants. WHOI’s mission comes at a crucial time to advance human understanding of this vast frontier.

Plan

With this mission, WHOI aims to form a new body of knowledge that will promote responsible stewardship of the ocean and shed new light on how our planet works. WHOI's scientists, engineers and technicians are doing this by continuing their groundbreaking work developing new generations of smart robots and other tools necessary to explore the zone. The mission began by deploying autonomous underwater vehicles and sensors in the Atlantic Ocean, offshore from the recently created Northeast US Shelf Long-Term Ecological Research (LTER) site. Subsequent cruises have conducted research in the Northeast Pacific and off the coast of the Bahamas.  The stage is now set to open the twilight zone to comprehensive study, laying the groundwork for a network of hardware, software and data throughout the ocean worldwide.

Why will this succeed?

Exploring the twilight zone demands unprecedented depth and breadth of experience, and WHOI researchers have a long track record of pioneering ocean research, as well as experience building novel robots and sensors. They are a leading voice in ocean science and exploration, and their ability to conceive, build and deploy new underwater technologies is unparalleled. The twilight zone sits largely beyond national jurisdiction and holds massive potential for commercial fishing, which puts it at risk of unregulated extraction. The data collected by WHOI will help fuel smart policies that support sustainable use of the twilight zone in locations all around the world.