Results of the krill and oceanographic survey under the NEWREP-A in the Antarctic in 2017/18
Atsushi Wada, Toshihiro Mogoe, Shunjiro Banjo, Hidenori Kasai, Yasuaki Saskai, Tsutomu Tamura
International Whaling Commission
The krill and oceanographic surveys were conducted in the Antarctic area V-E and VI-W during the 2017/18 austral summer season as part of third dedicated sighting survey of the New Scientific Whale Research Program in the Antarctic Ocean (NEWREP-A). These surveys, which were conducted by two research vessels Yushin Maru No. 2 (YS2) and Kaiyo Maru No. 7 (KY7), are associated with the main objective II of NEWREP-A. The krill survey was conducted along the zig-zag tracklines designed for the whale sighting survey. Acoustic data using quantitative echosounders EK80 (YS2) and EK60 (KY7) were recorded continuously for total 73 days and 6,608 n.miles. Net sampling using a small ring net (YS2 and KY7) and an Issak-Kid Midwater Trawl (IKMT) (KY7) was carried out to identify species and size composition of plankton echo signs at 47 stations and 11 stations, respectively. Oceanographic observations were also conducted at 112 stations using a Conductivity-Temperature-Depth profiler (CTD) and seawater sampling occurred at 16 stations. Calibration among EK80 and EK60 quantitative echosounders, and simultaneous samplings between small ring net and IKMT were also conducted. Krill and oceanographic data are currently being examined, and results will be reported in related CCAMLR working group and/or the mid-term review of NEWREP-A.