By Shannon Brown, CICOES

The Ocean Molecular Ecology (OME) group at NOAA’s Pacific Marine Environmental Laboratory—which is supported by several CICOES scientists—is expanding its technological capabilities to monitor long-term marine ecosystem dynamics across the Pacific Northwest and U.S. Arctic through the collection and analysis of environmental DNA (eDNA), the genetic material of living organisms that has shed into the surrounding waters. Building on five years of deployments using the McLane Phytoplankton and Particle Sampler (PPS) in the Olympic Coast National Marine Sanctuary and Alaskan waters, OME is moving toward more frequent, automated observations over longer periods. To achieve this, OME and the Engineering Development Division (EDD) are evaluating the newly acquired McLane Robotic Cartridge Sampling Instrument (RoCSI) on stationary moorings under a Cooperative Research and Development Agreement (CRADA). While previously deployed on robotic platforms, such as remotely operated vehicles (ROVs), this testing focuses on its mooring performance. The 6,000-meter depth-rated RoCSI features a smaller footprint and holds up to 48 sample cartridges, offering expanded sampling capacity compared to current OME field units.

In close collaboration with CICOES engineer Courtney Avioli, we have been testing and adapting the instrument for moored operation:

• In-House Testing: We put the new unit through its paces in the lab, running a series of creative stress tests, including using food coloring to trace water flow and to measure flushing volumes, and tilting the unit to see how the cartridge rotor handles rough sea motion. We sent detailed feedback to McLane, driving key hardware and software upgrades.
• Mooring Adaptation: Courtney designed and constructed a temporary mooring cage and cartridge hopper tailored for the initial testing phase.
• Successful Field Test: In late May, the unit completed its initial pilot deployment in Puget Sound aboard the S.P. Hayes, successfully collecting eDNA across 34 of 38 planned sampling events. For direct comparison, it was deployed alongside a PPS unit, which completed all 24 of its planned sampling events.

Following the field test, the instrument was returned to McLane to repair an injector issue encountered during preparation for the May deployment. Up next, we are preparing for a 3-month local deployment, scaling up closer to the unit’s full 48-sample capacity while testing how it handles ocean biofouling (marine growth) over time. This winter, OME plans to work with EDD to further upgrade the frame and cartridge capacity, paving the way for full deployments in Alaskan waters in upcoming field seasons.

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