Krill biomass in Area 48 and Area 58: recalculations of FIBEX data
FIBEX acoustic and length frequency data held in the BIOMASS database were used to provide estimates of mean density and biomass for the Indian Ocean sector and the West Atlantic sector as well as for FAO Statistical Area 41, and CCAMLR Subareas 48.1, 48.2, 48.3, 48.6 and Division 58.4.2. Density estimates were calculated using the target strength relationships used at the original FIBEX acoustic workshop. Estimates for the different areas were also calculated using the target strength relationships of Green et al. (1990). The new estimates were on average 4.76 times larger than the old estimates for those cruises (seven out of the nine considered) that used an echosounder frequency of 120 kHz.