Soviet krill fishery in 1977–1992, Part 1. Distribution, fishing effort, interannual situation patterns

The data on Soviet krill fishery in i977-1992 are presented. The fishing effort (FE) developed in 1977-1991 was 50086 fishing days in total. According to the pictures presented FE was distributed between subareas 48.1, 48.2 and 48.3. Monthly FE distribution between subareas revealed the three types of FE distribution in subsequent groups of years: Type I: 1981 and 1982, partly 1979/1980: FE was concentrated in subarea 48.1 in January-April, then moved to 48.3 via 48.2. Type II: 1983, 1984, 1985, and 1986: FE was developed mostly in subarea 48.2, since 1985 the role of 48.3 is increasing. Type III: 1987, 1988 and 1989. FE was developed mostly in 48.3, from March-April to September-November. There are discussed several groups of factors influencing FE distribution, it is very difficult to determine the key one between them. However, it was revealed that the determined types of FE distribution well correspond to spatial and temporal variability of the zonal and meridional atmospheric processes. The prerequisites for the main fishing effort development exist in the subarea where Southern transfers are maximally developed for the moment. The phenomena occur in subareas 48.1 and 48.2 under increase of the zonal western transfers and in subarea 48.3 under their decrease.