Established in 1989, Station M (4,000 meters depth) is one of three long-term abyssal time-series study sites worldwide, and the only site where carbon supply and demand have been recorded as a time series. Persistent monitoring by autonomous instruments has revealed the influence of climate and surface conditions on abyssal communities. Our ultimate goal is to model the carbon cycle from the surface to the seafloor. Our recent results have shown an increase in very large carbon-supply events, during which months- to years-worth of marine snow (i.e., food for marine communities) fell to the seafloor over short periods. These events are important to the carbon cycle, but they are not currently accounted for in models used to assess oceanic carbon sequestration. Our current focus is to understand what drives these important events, and how they impact abyssal communities.
During this cruise, we will bring the suite of instruments deployed at Station M up to the surface to change their batteries, download data, clean their o-rings, and make repairs if needed. This is not a small feat as the list of instruments includes: the Benthic Rover, two sediment trap moorings with time-lapse cameras at the base, the Sedimentation Event Sensor, and an ADCP current meter!
Senior Mechanical Technician Johnny Ferreira poses with the Benthic Rover on the back deck of the R/V Western Flyer. The Benthic Rover is an autonomous vehicle that cruise along the seafloor at nearly 4,000 meters deep!
We will also use the ROV Doc Ricketts to collect animals for food web studies, sediment for carbon and molecular studies, and video transects for studying change in animal community ecology. The ROV Doc Ricketts pilots will also deploy grab respirometers for studying oxygen consumption during the cruise, and larval settlement traps (for collaborator Luciana Génio), which we plan to bring back to the surface next year. Finally, we plan to use the CTD rosette to collect water for midwater molecular studies. This will be a busy cruise for sure.