THE CCAMLR-2000 KRILL SYNOPTIC SURVEY: A DESCRIPTION OF THE RATIONALE AND DESIGN

The design of the CCAMLR-2000 Krill Synoptic Survey (CCAMLR-2000 Survey) is described. The primary objective of the survey was to improve estimates of the preexploitation biomass of krill which are used in models to estimate sustainable yield in Area 48. The survey design includes two large-scale oceanic strata: one in the southwest Atlantic located in the Scotia Sea, and the other to the north of the Antarctic Peninsula (CCAMLR Statistical Subareas 48.1,48.2,48.3 and 48.4). Within these large-scale strata, four mesoscale strata were included in the survey design; these were located close to the South Sandwich Islands, north of South Georgia, north of the South Orkney Islands and north of the South Shetland Islands. The rationale underlying the selection of the strata and survey boundaries is described. The methods used for selecting the location of each survey transect are explained and the planned cruise tracks for each of the four vessels participating in the survey are shown. Details are also described for adaptively modifying the survey during its execution. This includes information how net haul stations sl~ould be selected and how transects should be modified if the planned survey tracks cannot be completed.