Dynamic of the krill fishery in the Area 48 and its relation to climate variability and changes in fishing technology

The authors analyzed the spatial-temporal structure of standardized indices of catch per effort unit (CPUE)  of Antarctic krill fishery in the Area 48    in  relation to dynamic of ААО indices (Antarctic Oscillation Index) as one of the factors used in analysis of inter-annual and long-period fluctuations of hydrometeorological conditions at high latitudes of the southern hemisphere.  Standardization of CPUE values was calculated on the basis of generalized linear models method with mixed effects (GLMM). Analysis of the time-series of CPUE and AAO indices were carried out using the modern de-nosing data methods, including wavelet transform, Markov’s regression model to determine the fishery regime shifts and multivariable wavelets de-noising. The influence of climate variability was traced in the long-term dynamics of fleet operation including standardized indices of catch per effort unit (CPUE), monthly catches and catches per vessel day.  It was shown that the most important evidence of ongoing climate variability is the fishery regimes switching observed in long-term fishery in the Area 48. It was found that the most significant switching of fishery regime occurred in 2006-2011, when fishery had transferred to the state «high CPUE». This period is characterized by the highest values of CPUE and AAO indices for the whole observation period 1985-2011.  Analysis of krill fishery indices obtained with using different fishing technologies revealed that the “high CPUEs” regime is not associated with the changes in fishery technology and using the continuous fishing method, but is due to the influence of the current climatic changes.