Spring Expeditions: Keeping OOI Arrays Fully Operational

The Endurance Array 14 team is aboard the R/V Sikuliaq as she goes under the bridge at Newport, Oregon. The team will be at sea for 14 days recovering and deploying equipment to keep the array operational. Credit: David Neiman, OSU

OOI teams were in the water on opposite coasts in late March to service the Pioneer and Endurance Arrays. The teams will “turn” the moorings (recover old and deploy new) to keep the arrays continually collecting and reporting data back to shore. This is the 14th turn of the Endurance Array; the 16th for the Pioneer Array.

The Endurance 14 Team set sail from Newport Oregon aboard the R/V Sikuliaq on 24 March for a 15-day expedition. The Pioneer 16 Team departed from Woods Hole, MA, a few days later on 29 March aboard the R/V Armstrong for a 21-day mission. Both expeditions will require two legs because of the need to transport a huge amount of equipment. The equipment for the Pioneer Array weighs more than 129 tons. The Endurance equipment tops the scale at 95 tons.

Departures for both teams occurred after arranging for reduced occupancy on site and social distancing during preparation, followed by 14 days of quarantine to meet COVID-19 restrictions. And while onboard, COVID has necessitated other changes ranging from smaller science parties to scheduled meal times to allow for social distancing.

“It is very impressive that the OOI team has been able to continue to service these arrays in spite of the challenges presented by COVID,” said Al Plueddemann, Chief Scientist of the Pioneer 16 Expedition. “The ocean is a tough environment in which to keep equipment operational, even in normal times. This year, in particular, has required both our shore-based staff and those onboard to be adaptable, flexible, and innovative to get the job done.”

The full cycle of preparation for an OOI mooring service cruise takes many months. The “burn-in” period for Pioneer-16, during which equipment is assembled and tested, began in January 2021 with snow on the ground outside of the LOSOS building on the WHOI campus. Credit:Rebecca Travis © WHOI.

In addition to the mooring and deployment recoveries, both teams are deploying and recovering gliders that collect additional data within the water column and the area between the moorings. They also are conducting CTD casts and water sampling at the mooring sites, and doing meteorological comparisons between ship and buoys. The Pioneer Team will be operating autonomous underwater vehicles (AUVs), while the Endurance Team will have its inaugural use of OOI’s own remotely operated vehicle (ROV) to recover anchors at the Oregon shelf site.

“In normal times, we would invite external students and scientists along to conduct ancillary experiments on the cruise,” said Edward Dever, Chief Scientist for Endurance 14. “But given the limited science party allowed onboard due to COVID-19, the OOI team will be conducting some of this additional work to ensure the continuity of these experiments.”

For Endurance 14, this work includes collection of organisms that grow on panels attached to Endurance buoys for invasive species research, collection of settling organisms on devices attached to Multi-Function Nodes, which power near bottom data instruments, and test deployments of tagged fish acoustic monitors on near surface instrument frames on three moorings.

Likewise, the Pioneer 16 Team is helping ensure ongoing science investigations installing and operating unattended underway sampling for the Northeast U.S. Shelf Long-Term Ecological Research (LTER) project and conducting CTD casts at LTER sites during the cruise. They will also conduct communication tests at the Offshore mooring site in support of the Keck-funded 3-D Acoustic Telescope project.

Science teams of 9-10 people on each cruise are sharing the multitude of tasks needed for the moored array service.

OOI’s remotely operated vehicle will be used for the first-time during Endurance 14. Credit: Seaview Systems.