Deploying the Moorings

For the fifth year in a row the IVARS group deployed two moorings in the Southern Ross Sea. Vernon L. Asper (University of Southern Mississippi) prepared all the hardware and most of the sensors in Lyttelton, NZ. The two moorings (Calinectes and Xiphias) have similar configurations, each bearing a surface float equipped with an Argos satellite transmitter that regularly sends us the mooring position via e-mail. In the top 50 meters we mounted three Wetlabs fluorometers, a Chelsea Fast Repetition Rate Fluorometer (FRRF), a MBARI-ISUS nitrate sensor (only on Calinectes), a Microcat temperature/salinity recorder, and a Benthos transponder. A 240-meter S-Tether connects the surface part of the mooring to the bottom portion. The bottom array consists of a 40" Syntactic float, a current meter positioned at 210 meters below the surface, followed by a sediment trap, which is used to measure settling rates of particulate matter in the lower water column (see picture). Each mooring also has 10 glass floats attached to a Dual Edgetech acoustic release and a 2,200 pound anchor made of train wheels. SED Trap


We deployed the first mooring, Xiphias, most eastward, at 77° 39.98 S 179°59.94 W in a depth of 662 m. Exactly 30 hours later, we deployed Calinectes at (76°54.600S and 171°46.550 E) at a depth of 665 m. Thanks to calm seas and excellent support of the ship crew, both moorings were smoothly deployed in exactly two hours each. The back deck team had Annie Coward at the winch, Pete Delferro and Meghan King at the transom, and Skip Owen coordinating all the operations. Robert Dunbar and Dave Mucciarone (Stanford University) used their experience in mooring deployments to ensure the correct sequence of operation. Sasha Tozzi was responsible for the Chelsea Fast Repetition Rate Fluorometers (FRRF), and the MBARI-ISUS nitrate sensor and all other scientific equipment on the mooring. Isaiah Norton (ship Network Administrator) helped Sasha secure many of the sensors.

The moorings are scheduled to be recovered on February 1st, in conjunction with the last IVARS cruise. Until then, we hope for continued good weather and low ice conditions!