Pulling Out All the Stops

Mission Overview

For this expedition, the OTZ team will embark on an unprecedented four-ship expedition in the northwest Atlantic, using two research vessels (R/V Endeavor and R/V Henry B. Bigelow), and a commercial fishing vessel (F/V Monica). The work of these three ships will be supplemented by an unmanned, AI-driven surface ship (USV Mayflower 400), which will survey the same area after the crewed vessels return to port.

While at sea, the team will deploy almost every tool it has developed to study the twilight zone over the last three years, including Mesobot, Deep-See, TZEx, ROAM tags, MINON floats, and eDNA samplers. This technology will be used in conjunction with the new Twilight Zone Observation Network, which will let scientists accurately track positions of tagged apex predators as they forage deep in the twilight zone. (The network will also continuously monitor the movements of marine organisms as they migrate up and down through the water each day, and will help researchers measure the downward movement of carbon from the surface).

Each ship will serve a different yet complimentary purpose on this voyage. The Monica will capture and tag sharks that dive into deep water to feed, helping the OTZ team understand these predators' behavior in the twilight zone. The Bigelow will characterize migrating fish and other organisms, both by capturing them in traditional nets and viewing them with using acoustic signals from the Deep-See towed vehicle. On the Endeavor, scientists will measure the movement of carbon through the twilight zone, collect images of gelatinous animals with the Stingray Tow Sled, gather environmental DNA for analysis, and deploy Mesobot to capture acoustic data, light data, video footage and still images.

After the crewed ships complete their operations, the nimble, autonomous Mayflower will then comb the waters that the other three ships studied using onboard sonar and other instruments—plus data from the tagged sharks—to continue monitoring the twilight zone. All the data collected by each vessel will be coordinated and cross-referenced with data collected from the other vessels.

While each of these different activities is exciting in its own right, the combination of all this research on one mission is truly groundbreaking. In collecting dozens of complementary datasets, OTZ researchers will gain a previously unattainable level of detail on the twilight zone.

Clockwise from top left: the R/V <i>Endeavor</i>, F/V  <i>Monica</i>, R/V <i>Henry B. Bigelow</i>, USV <i> Mayflower 400</i>
Clockwise from top left: the R/V Endeavor, F/V Monica, R/V Henry B. Bigelow, USV Mayflower 400

Quick Facts

DatesAugust 6-19, 2022
LocationNorthwest Atlantic
ShipsR/V Endeavor, R/V Henry B. Bigelow, F/V Andrea, USV Mayflower 400
Chief ScientistHeidi Sosik
Scientific Objectives
  • What role does daily vertical migration play in the movement of carbon through the twilight zone?
  • What percentage of the twilight zone population migrates vertically?
  • What triggers that vertical migration?
  • Where and how do top predators prefer to forage?
  • How does eDNA correlate with biomass?
  • Can we use acoustic information to ID specific types of animals?
  • What are the food webs for gelatinous animals and fish in the zone?
  • Can we combine our samples and data to estimate twilight zone biomass?
TechnologyMOCNESS tow net, sediment traps, TZEx, Mesobot, Deep-See, ROAM tags, MINON floats, eDNA samplers, Stingray imaging sled, Observation Network acoustic sound sources, bioacoustic sensors, Imaging Flow Cytobot (ICFB), Equilibrator Inlet Mass Spectrometer

Field Notes: All is not lost

By ehugus | August 11, 2022

The echogram from aboard the R/V Bigelow shows a distinct three-layer migration of creatures coming from twilight zone depths to…

Field Notes: Technical difficulties

By ehugus | August 10, 2022

An engineer supervises as the MOCNESS is deployed for the first time during this OTZ cruise. The winch failed while…

Field Notes: The big reveal

By ehugus | August 9, 2022

The Deep-See is pulled back on board after its first deployment. The vehicle is used for acoustic monitoring and gathering…

UPDATES FROM THE FIELD