Knowledge of abundance and rates of change of abundance are basic requirements for fisheries models. Catch per unit effort (CPUE) has traditionally been used in demersal fisheries assessments as an estimator of abundance. It is less satisfactory for pelagic fisheries. Evidence is given that CPUE estimated from data reported to the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) does not provide a realistic index of krill abundance.

Recognising that there is a large natural year to year variation in krill abundance it is important that this be quantified and separated from fishery induced variation. The timescale for such information is discussed in the light of the needs of fishery management.

(In press in: Sahrhage, D. (ed). Antarctic Ocean and Resources Variability.
Springer. Berlin, Heidelberg, New York, Tokyo).