Yesterday we said goodbye to a foggy Moss Landing as we headed out to deploy the SINKing Ecology Robot (SINKER) at MARS, MBARI’s cabled ocean observatory located on the deep seafloor just outside of Monterey Bay. After successfully deploying the instrument using the A-frame on R/V David Packard, we launched the remotely operated vehicle (ROV) Doc Ricketts and our team of skilled ROV pilots plugged SINKER into the MARS node to power our camera systems and enable real-time data transmission. 

After the ROV dive, we proceeded to deploy the surface-tethered trap (STT), a free-drifting array of sediment traps that collects sinking particles at five depths from 100 meters (330 feet) down to 500 meters (1,640 feet). Our recently built SnoCam+ cameras were attached to the collection frames at four of these depths. These time-lapse cameras will help us see day/night variability in particle fluxes. 

Two of MBARI’s long-range autonomous underwater vehicles (LRAUVs) met us at the STT deployment coordinates, collecting images of plankton, particles, and animals with their onboard Planktivore and Triton imaging systems and measuring the physical conditions of the research site. The STT is equipped with a beacon, and the LRAUVs will use this acoustic signal to maintain proximity and sample the area around the deployment. 

Finally, we conducted two CTD casts. CTD instruments profile salinity (via conductivity of seawater) and temperature with depth. The first cast occurred in the afternoon while the sun was still up, and we collected water samples and deployed the ISIIS shadowgraph camera to capture images as the CTD descended through the water column. The second cast occurred after sunset and involved only the ISIIS camera. We hope these day versus night casts will allow us to detect the impact of animal migration on the distribution of particles in the water column.