G-35 



8.8 



Biomaaa, Production and Yield 



The very recent build-up of fisheries in the Antarctic has meant that only limited 

 information on biomaos and production is available and this is dinperaed in a variety of 

 publications. Tlicre is nowhere in the literature a detailed analysis of information suit- 

 able for fishery mana,<Tomcnt decisions. The analysis which followB should be considered as 

 a first approximation (as far as Antarctic endemic fish are concerned) that wil] require 

 updating as more information from the fishery becomes available. The need for precise 

 reporting of catches by species has been clearly understood for some time in most sea areas 

 and it is hoped that the recommendations in Section 11.2 for the Antarctic areas will result 

 in much impro-'fed stock estimates in future years. 



The joint ACMR/CARPAo working group on the fish stocks of South America (fAO 1974) 

 gave information (Table 8.31) for MicromcGistius ' aus tralis and Merluccius hubbsi , the two 

 species that are thoufjit to migrate into tlie Antarctic. 



Table 8.31. Fish Stock assessments for Patagonian species which migrate into the 

 Southern Ocean (Data from ¥'^U 1974) 



The working ,'^oup considered the Hake as consisting of several distinct management stocks 

 limited geographically. The above results relate Lo the most northern group (35 - 45°S) 

 which represents the greater part of the present fishery. It is not clear how these figures 

 can be applied to the southern end of the range, bul in viei-f of the slower growth rate su^ 

 gested by Ilikheyev (1967) the optimum sustainable yield is likely to be less in proportion 

 to the biomass at the hij[^er latitudes. T'here is no information on biomass in the Southern 

 Ocean or on the proportion of the southern stock that migrate further south. 



The estimates for Micromnsistius are clearly based on very limited information and as 

 with Merluccius there is no information to indicate the proportion of the population migrating 

 south. Thin information is not likely to become available until commercial fishing takes a 

 much larger proportion of the optimum sustainable yield. Regarding these two species since 

 the available evidence suggests that they are migratory species it is probably best for the 

 time being to assume that catches from the Scotia Sea area are of Patagonian fish. 



There is no information on which to base estimates of ^.SY for stocks of MioromesistiuB 

 at Kerguelon or South of New Zealand. T'his should become a management priority now in view 



of the reported catch of over /\0 000 tons in area 

 Campbell Plateau area (see Ghimtov 1971). 



01 



this was probably taken from the 



In the section 8.7 it vno suggooted that a large proportion of the reported catch of 

 "Unapecified Demersal Percomorphs" in some areas adjacent to Antarctic waters was largely 

 made up of Antarctic Ilototheniiforms. T'here is no firm confirmation of this fact, but all 

 available evidence indicates that this Ic correct. 



