In a first for the southern ocean, the Deep Sea Probe Argo was recovered from waters about 500km/310 miles south of Tasmania.
The recovery was done by Australia’s CSIRO research vessel (RV) Investigator, and it came after the probe spent three years sampling these deep waters.
The probe spends most of its time parked at a depth of 1,000m/3,300ft; it then sinks to 2,000m/6,600ft to take measurements and samples. Every 10 days, the probe returns to the surface, where it transmits its data via satellite uplink before plunging to the depths one more time. In its three-year mission, the probe provided data on various things, including oxygen nutrients, light, seawater pH, and more.
Commenting on the work, CSIRO scientist Dr. Christina Schallenberg stated:
“In addition to the full set of biogeochemical sensors, this float has an Underwater Vision Profiler, which is basically a camera that takes pictures of particles in the water column. While the float is only able to transmit counts of particles, it should have stored the actual images. Now we’ve recovered the float, we’ll get access to the images. Not only will this tell us the size of particles, but what they are – faecal pellets, fresh plankton, other detritus – which is crucial for knowing how the sinking of these particles moves carbon from the surface to the deep ocean.”
