@ARTICLE{Sosiński_Józef_State_1993, author={Sosiński, Józef and Paciorkowski, Andrzej}, volume={vol. 14}, number={No 4}, journal={Polish Polar Research}, pages={407-431}, howpublished={online}, year={1993}, publisher={Polish Academy of Sciences}, publisher={Committee on Polar Research}, abstract={Results of Polish biological investigations and surveys on the state of mackerel icefish (Champsocephalus gunnari Lonnberg, 1905) stock served to undertake an attempt at an independent estimation of some of its biological parameters as well as at the assessment of its biomass and fishing mortality during 1975/76—1991/92 fishing seasons with virtual population analysis (VPA) method (using MAFFVPA programme). Laurec-Shepherd and hybrid methods were applied for the VPA tuning. Von Bertalanffy equation parameters were estimated and compared with those published earlier. F0l and F max values were assessed using Beverton and Holt model and Thompson and Bell method. Based on data from available literature the coefficient of natural mortality (M) was assumed to be 0.5. VPA results indicate that the total stock biomass (TSB) during the last 1991/92 season amounted to 34,818 tonnes and was approximately 10 times lower than in 1975/76 season. Spawning stock biomass (SSB) declined to a minimum of 7,396 tonnes in 1989/90 season. The assessment results point out to the recruitment as a major factor contributing to the stock fluctuations.}, type={Article}, title={State of mackerel icefish (Champsocephalus gunnari Lonnberg, 1905) stock from South Georgia area based on Polish biological investigations in 1975 — 1992}, URL={http://ochroma.man.poznan.pl/Content/111073/PDF-MASTER/1993-4_407-431.pdf}, keywords={Antarctic, South Georgia, mackerel icefish, assessment, biomass}, }