Fish and krill schools and regions detected from acoustic backscatter along the slope of the Central Beaufort Shelf, Aug-Sept. 2018

he goal of this study is to reveal the spatial variation of biological backscatter and the distributions of fish (assumed Arctic cod) and zooplankton (assumed euphausiids/krill or large copepods) in a region of the Beaufort Shelf known for intense upwelling. Data were collected during two cruises to the Central Beaufort Sea Shelf in 2017 (Aug. 25 – Sept. 19) and in 2018 (Aug. 3 – 27) using the Simrad EK80 bioacoustics sonar suite located on the centerboard of the Research Vessel (R/V) Sikuliaq. Fish (assumed Arctic cod or Boreogadus saida) schools and regions (portions of the water column with contiguous presence of fish) were identified using the 38 kilohertz (kHz) data while krill (euphausiid) schools and regions were identified using the 120 kHz data. All processing and analyses were conducted in Echoview. This dataset contains preliminary data from 2018; problems with calibration are delaying final data sets.