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 pre-exploitation biomass of krill which are used in models to estimate sustainable yield in Area 48. The survey design includes two large-scale o ceanic strata: one in the southwest Atlantic located in the Scotia Sea, and the other to the north of the Antarctic Peninsula (CCAMLR Statistical Suba reas 48.1, 48.2, 48.3 and 48.4). Within these large-scale strata, four meso scale strata were included in the survey design; these were located close t o the South Sandwich Islands, north of South Georgia, north of the South Or kney Islands and north of the South Shetland Islands. The rationale underly ing the selection of the strata and survey boundaries is described. The met hods 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 sta tions should be selected and how transects should be modified if the planne d survey tracks cannot be completed. The survey took place in January-February 2000 and involved ships from Japa n, Russia, UK and the USA. Scientists from many more CCAMLR Member States a nd the International Whaling Commission (IWC) took part. The survey is by f ar the biggest single exercise ever carried out by Members in support of th e Convention. Full analysis of the results of the CCAMLR-2000 Survey will t ake several years and will result in a significant increase in the knowledg e of krill length frequencies, biomass and distribution in the area studied .