Woods Hole Oceanographic Institution
The Ocean Twilight Zone (OTZ) Project employs cutting-edge research and technology to help us understand how the extraction of resources from the twilight zone — a global ecosystem deeply intertwined with the entire marine food web and Earth’s climate system — could reverberate for centuries to come. By advancing human understanding of this vast new frontier, the OTZ Project will fuel smart policies for ocean stewardship, and shed new light on how our planet works.
Photo caption: The ocean’s twilight zone is home to more than a million new species. / WHOI
In the first quantitative assessment of twilight zone ecosystem services, the OTZ Project showed that the zone’s Biological Carbon Pump (BCP) — responsible for transporting carbon from the ocean’s surface into deeper waters — sequesters 2 to 6 billion metric tons of carbon annually. This is at least double, and perhaps as much as six times, the amount of carbon emitted by all automobiles worldwide.
Deep-See, a new OTZ survey tool, discovered that previous estimates about the total fish biomass in the twilight zone (10 billion metric tons) are likely overstated. Because commercial fishing interests use these estimates as a basis to exploit and harvest twilight zone species, Deep-See’s discoveries constitute a critical insight for developing new high seas fisheries management policies.
The OTZ Project is also influencing policies that impact the high seas. Currently, the United Nations is using their research to promote the sustainable use of the oceans and the conservation of marine biodiversity in areas beyond national jurisdiction, including the negotiations for a new treaty on Biodiversity Beyond National Jurisdiction (BBNJ).
Meet OTZ’s Mesobot
In March 2020, the purpose-built OTZ hybrid robot, Mesobot, participated in an OTZ research mission aboard WHOI’s research vessel Neil Armstrong. Mesobot put an array of sophisticated instrumentation to the test, executing five dives to 850 meters, surveying the twilight zone for 14 hours, collecting dozens of eDNA samples, capturing hours of video featuring strange lifeforms and precisely measuring light levels using a prototype radiometer. OTZ scientists are currently preparing a journal paper on the performance of the radiometer and related Mesobot operations.
“The ocean is referred to as the lungs of the planet, and the pandemic has done nothing if not raise our awareness of the importance of healthy lungs. Some of the most important work to come out of the project this year relates to the crucial role played by the Ocean Twilight Zone in sequestering carbon dioxide to the depths of the ocean.”
Mesobot is deployed for the first time. / Woods Hole Oceanographic Institution