Search title, summary and keywords


Acoustic Doppler Current Profiler (ADCP) data from shallow and deep ocean moorings deployed on multiple marine cruises investigating krill abundance variability around South Georgia, 2002-2006


Acoustic Doppler Current Profiler (ADCP) data collected in the Southern Ocean, northwest of South Georgia, between 2002 and 2006. The ADCP measures speed and direction of the water current at different levels of the water column, as well as recording the backscatter of zooplankton in the water column (it used sound waves of 300kHz).

Data were collected by deployment of sub-surface moorings equipped with physical and biological sensor systems. The main buoys with the sensor systems were designed to float 200m below the water surface, to minimise the impact of icebergs while giving good sample coverage for the upper water column. The acoustic instruments were oriented upwards towards the surface and each mooring had 3 monitoring systems on-board: 1) a water column profiler (WCP), 2) an Acoustic Doppler Current Profiler (ADCP) and 3) a Conductivity/ Temperature/ Depth (CTD) analyser.

This work took place as part of a project to: a) quantify the magnitude and timing of short-term, ecologically-significant, intra-annual variability in krill abundance at South Georgia; b) describe the effect of oceanic tides at the two locations; c) test the hypothesis that krill immigration to, and hence abundance at, South Georgia is mediated by influx of cold waters; and d) determine functional responses of predators to short term variations in prey (krill) abundance. Antarctic krill (Euphausia superba) is of vital importance to the South Georgia marine ecosystem providing food for a high proportion of Antarctic wildlife, and is eaten by most animals (seals, whales, birds, fish, squid, penguins).

acoustic backscatter, biological sensor, mooring, physical sensor, upper water column

Basic Information