Aglantha ROV coming back from deep waters
Scientist facing the ROVs monitor
Date:June 22 2004
Author: Astthor Gislason, Marine Research Institute, Iceland and Marc Picheral, CNRS, Laboratoire dOceanologie de Villefranche, France
Early in the morning we completed the last station in the mid-box. We then steamed southwards for a transect that is located approximately mid way between the mid-box and the southern box. On the way we deployed an acoustic lander of the same type as the one that was deployed on June 17. Once the lander was deployed on a 900m sea mount, the Aglantha ROV (Remoted Operated Vehicle) was put out for the second inspection dive of the cruise.
After struggling against deep currents, the lander could be found at 890m using the high quality positioning system of the GO Sars and the sonar of the ROV.
This ROV (photo) is now owned by IMR, built in 1998, it has been recently upgraded to include more powerful thrusters (motors used to displace the system underwater) and more buoyancy. It is a stable oceanographic platform for science and investigation down to 2000 meters. Easy to manoeuvre, it has many cameras, which allows scientist to view underwater in real time as images are transmitted via the electro-optical umbilical. It can also be fitted with sampling gears or a manipulator arm. As the aim of the dive was only inspection, none of these accessories were installed.
After having inspected the lander site, we could survey the sea-floor around the mooring. The scientists remained very attached to the real time displays of benthic animals (photo). We saw some fascinating images of the living world in the deep ocean (see video-clip)
At todays meeting the main results from the zooplankton group were summarized. We collect information on zooplankton with a number of gears and instrumentation - acoustics, UVP (Underwater Video profiler), Multinet (photo), Juday net and Macrozooplankton/Micronecton trawl - each one designed to sample specific size categories of zooplankton. It is therefore very important to compare catches between the different gears. Until now, the findings indicate, that the biomass and productivity of zooplankton is relatively high in the frontal area located near the Charlie-Gibbs Fracture Zone.