Analysis and modelling of the Soviet Southern Ocean krill fleet, II: Estimating the number of concentrations and analytical justification for search data

In this paper, I show how data that are routinely collected by survey vessels can be used to estimate the number of Concentrations of krill (in the sense of Butterworth (1988), Mangel (1988)) in a given region of the southern ocean. Sample computations are performed, using data collected by Soviet research/survey vessels in the early 1980s. These examples highlight the need for a navigational log as well as a fishing log in order to make accurate inferences.