Biology, distribution and abundance of Antarctic krill (Euphausia superba) and by-catch

During the First Indian Antarctic Krill Expedition (FIKEX), krill samples were collected from 34 stations of fishing area 58 in Indian Ocean sector of Antarctic region between lat.57°53'S to 61°13'S and long.30°02'E to 40°05'E. These were analysed onboard FORV Sagar Sampada for the study of biology, distribution and abundance. The samples were collected for a period of 18 days from 26th January to 12th February '96. Three types of gears were used viz. Isaacs Kidd Midwater Trawl (IKMT), 49.5m krill midwater trawl (Cosmos trawl Denmark) and 42m Polish krill midwater trawl. The length frequency analysis indicated a bimodel distribution with 19-20 mm and 53-54mm as the most abundant size in the fishing area 58. The average sex ratio of male and female Euphausia superba was observed to be 1:l.17 though it differs from swarm to swarm. The analysis showed that 47% of krills with high intensively feeding population and 25% with moderate feeding population which indicate the feeding of krill and availability of food in the area surveyed. Maturity stage IV (fully matured) was maximum among both the sex followed by stage V (spawned), indicating spawning period. Of the total catch of 12.470 tomes recorded, krill constituted 45.6% and the by-catch 54.4%. The by-catch included salps 54%, Antarctic squid 0.07%, jelly fish 0.02% and fin fishes 0.13%.