Acoustic backscatter from sites in McMurdo Sound from 2014-2015 (McMurdo Predator Prey project) (NCEI Accession 0278519)

This dataset contains optical and physical data collected on shoreside McMurdo_Backscatter during deployment McMurdo_Backscatter_2014-2015 in the South Pacific Ocean and Southern Ocean from 2014-11-23 to 2015-01-07. These data include beam attenuation and depth. The instruments used to collect these data include BioSonics DT-X Digital Scientific Echosounder and Remotely Operated Vehicle. These data were collected by Dr David G. Ainley of H.T. Harvey & Associates, Dr Stacy Kim of Moss Landing Marine Laboratories, Dr Grant Ballard of Point Blue Conservation Science, and Dr Kendra L. Daly of University of South Florida as part of the "Food web dynamics in an intact ecosystem: the role of top predators in McMurdo Sound (McMurdo Predator Prey)" project. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) submitted these data to NCEI on 2018-03-19.

The following is the text of the dataset description provided by BCO-DMO:

Acoustic backscatter from sites in McMurdo Sound.

Dataset Description:
Krill and fish were sampled acoustically and visually beneath the fast ice using the tethered SCINI ROV, which was deployed and operated through a 25 cm diameter hole drilled through the sea ice. SCINI contained cameras and thrusters, and towed a sensor package consisting of a WET Labs fluorometer (ECO-AFL/FL) and a single-beam Biosonics 120 kHz DT-X echosounder. Visual targets were identified to the lowest taxon possible; these observations were used primarily to verify classification of acoustic signals. The echosounder operated at a nominal ping rate of 1 ping s-1; however, this rate was occasionally adjusted if false bottom signals were observed. The general profile of a dive included a surface transect of ~300 m horizontal distance, where the acoustic transducer faced downward, and also a dive to ~120 m if conditions allowed. Echogram data were saved to a depth of 500 m, and background noise was removed. Given the effective range of the transducer of approximately 100 m (resolving -80 dB targets), surveys characterized the upper 200 m of the water column.