KRILL CATCHES INDICATE THE IMPACT OF THE EL-NIŇO – SOUTHERN OSCILLATION RELATED PROCESSES ON THE DISTRIBUTION OF KRILL BIOMASS BETWEEN SUBAREAS OF THE ATLANTIC SECTOR OF ANTARCTIC

This presentation addresses the need to incorporate recent studies aimed to identify different climate oceanographic regimes and its influence on krill biomass into the discussion of krill fishery management issues. Krill catch data in Subareas 48.1, 48.2 and 48.3 are compared to the AMLR Programme findings as described by Loeb et al. (2009). It is shown that krill fisheries statistics may be used to analyze the influence of the El-Niňo – Southern Oscillation (ENSO) related processes on the inter-annual variation of krill biomass distribution between the major statistical subareas. The analysis suggest that the dynamics of krill biomass in fishable aggregations in Subareas 48.1 and 48.2 is not synchronized while there are more connections between Subareas 48.1 and 48.3. Particularly strong negative anomalies of catches in the important Subarea 48.2 are seen in the year of oceanographical regime associated with La Niňa event in the South Pacific. The mechanisms for these phenomena associated with the role of the southern part of the Antarctic Circumpolar Current and the Weddell Gyre waters are discussed. In order to reach better understanding of the risks of different options for allocation of krill available catch to SSMUs the models should incorporate subarea specific krill biomass dynamics in the years with different oceanographical regime governed by ENSO.