A firsthand look at the twilight zone

Mission Overview

To close out the first year of the OTZ Project, our team  mobilized a research expedition in record time—under two weeks—and set sail on the OceanX research vessel M/V Alucia near the coast of the Bahamas. During the 10-day expedition, Joel Llopiz, Heidi Sosik, and several other OTZ team members made submersible dives to explore the twilight zone in person for the first time.

The overall goal of the cruise was to explore and better understand the zone's vast ecosystem, and to study its organisms in detail. Specific objectives included measuring water column properties; sampling environmental DNA (eDNA), pigments, and microplankton; collecting twilight zone zooplankton and fish with large net sysems, and using the Alucia’s submarine Nadir to view the twilight zone with cameras and scientists’ eyes.

Four locations—including the Tongue of the Ocean and the open waters of the Sargasso Sea—were successfully explored over the course of the mission. The samples and footage we obtained are helping our team understand differences in the composition and functioning of the twilight zone ecosystem at different latitudes.