VPA as one of the approaches for settling a problem of Patagonian toothfish, Dissostichus eleginoides, population quantity (Subarea 48.3, South Georgia)

In order to avoid several problems associated with assessing the D. eleginoides stock in Subarea 48.3, it has been proposed to use the FAO programme ANACO (Mesnil, 1989) which allows one to make coefficients of fishing mortality F more precise by using catch data on age groups without resorting to additional information on effort. VPBAS files for running the programme were created using our data as well as CCAMLR data. Some assumptions were made for this exercise. Assessments for the period 1984 to 1994 revealed that at a level of M = 14, the mean value of F is 0.148, while the toothfish spawning stock for 1989 to 1994 is between 17 and 29 thousand tonnes. The author believes that the ANACO cohort analysis programme has significant potential for further improving both stock assessments and calculations of F by adjusting the catch database and using variable parameters of natural mortality and mean fish weight.