Catch per unit effort (CPUE) data from the early years of commercail krill fishing operations in the Atlantic sector of the Antarctic
Catch per unit effort (CPUE) data are presented from krill fishing operations in CCAMLR Subareas 48.1, 48.2, 48.3 (South Atlantic) for the period 1975/76 to 1987/88. Comparisons are carried out between subareas in single years, between years on a subarea and area basis, and between oceanic and shelf regions. Results show that the CPUE may differ between subareas, years and shelf/oceanic regions. Obviously, a consistent pattern of CPUE values does not occur over time for the entire area. High average CPUE were observed in the years 1975/76 and 1980/81, whereas the lowest CPUE occurred in Subarea 48.3 in 1977/78. The validity of the CPUE index is discussed as an indicator of krill abundance/biomass and caution is expressed in this regard. Depending on the circumstances, a commercial CPUE index may seriously under- or overestimate the amount of krill available in a statistical subarea. Overall length-frequency distributions from commercial fishing operations in general tend to show little interannual variation because several factors influence the representativeness of krill smaller than 35 mm in the catches.