Supervised and unsupervised (RapidKrill) estimates of krill density from DY098

We compare supervised, using the interactive software Echoview™, and unsupervised, using python,  processing  of acoustic  data  collected  during  the  UK  cruise  DY098.  The  same  data processing procedures are applied in both methods, and we show that the unsupervised method comes  up  with  a  similar estimate  of krill  NASC  and  krill  density  as  the  supervised  method.  An estimate of krill density is supplied for the WCB survey using three methods. The multifrequency method produces a krill density of 8.60 gm^-2, compared with 21.76 gm^-2 (supervised) or 20.41 gm^-2 (unsupervised).