Analysis of spatial and temporal structure in long-term krill fishery in the Area 48 and its relation to climate variability

The authors   analyzed the influence of climate changes on space-time dynamic of Antarctic krill fishery in the Area 48 using the CCAMLR fishery data and time series of ААО induces (Antarctic Oscillation Index) as the indication of climate variability.   Here we used the methods of the integrated ecosystem assessment used by ICES and the modern de-nosing data methods. The influence of climate variability was traced across long-term dynamic of fleet operation including standardized CPUE indices, monthly and daily catches.  The important evidence of ongoing climate variability is the fishery regimes switching observed in long-term fishery. Standardized CPUE index was used as an indicator of probable fishing regime switching.   The peculiarity of such switching in the entire Area 48 and its Subareas 48.2, 48.2 and 48.3 is considered.  It was found that the significant switching of fishery regime occurred in 2006, when fishery transferred to the state «high CPUE» retained during 2006-2010.  This period is characterized by the highest values of CPUE index and AAO index   reached in the Area 48 for the whole 1986-2011 observation period.  It was shown that over 2006-2011years the observed shift of the fishing seasons towards fall-winter months of the Southern hemisphere are accompanied by the shrinking of the fishing season itself. The ongoing climate variability demonstrates the possibility of new fishing regimes switching which can impact on fishery structure in years to come.   Climate changes can become the reason for the changes in abundance, distribution and life cycle of krill affecting space-time variability of fishery strategy and performance. Therefore   to support developing the approaches for management of krill fishery the following factors seem to be urgent: availability of information sufficient to detect and understand regularities and trends in krill distribution in the Area 48; forecasting methods to predict possible fishery regime switching in the years to come.