CCAMLR

Traditional calculation of catch age composition estimate requires that the age-length data and random length frecuency be sampled from the same population, in other case an age-length key is capable of providing biased estimates of age distribution. By using the iteration algorithm is possible to overcome this limitation.
The catch age composition for Dissostichus eleginoides was obteined with the aplication of a single age-length key to all monthly length distribution using the nonlinear model (Hoenig and Heisey, 1987). We found a catch age distribution pattern wich is not significatly different from the one obteined by use of traditional method

With samples originated in the Chilean longline fishery of Dissostichus eleginoides of subarea 48.3 (N=7848) after Sparre (1990) the natural mortality was calculated . The Von Bertalanffy parameters obtained independently by three authors were used and considering as variables: fishing site, fishing depth and hook type.
It was determined that there was no significative differences, in M value, in the considered cases with the different growing parameters, with the exception of the case of fishing sites. By other hand, when comparing the different mean values of M for the different variables , it was found that there were significative differences between fishing sites and curve hooks N° 14 and straight hooks N° 22.
The general mean value of M calculated for the 44 analyzed situations was 0.14 ± 0.03, being the range between 0.0623 - 0.2727.

The incidence of entanglement of Antarctic fur seals (Arctocephalus gazella) in Man-made debris at Bird Island, South Georgia, was monitored throughout the austral winter and summer of 1991 as part of an on-going study by the British Antarctic Survey. Only seven seals were observed entangled during the winter months (April - October) while 48 were sighted during the pup-rearing period (November - March). Entanglement during the winter months was comparable to that during 1991 (7). While the incidence of entanglement during the pup-rearing period was slightly higher than in the previous year (48 compared to 30), it was substantially lower than during the 1988/89 and 1989/90 seasons (190 and 156, respectively). Polypropylene straps (44%), of the type used in packaging bands, and fishing net fragments (27%) were the most common item found on seals. These proportions are similar to those reported in previous years.

In the course of demographic studies of Arctocephalus gazella conducted at Cape Shirreff (62"27'S, 60°47'W) during the 1984185, 1987/88 and 1990/91 seasons, debris found on beaches was collected and transported to Santiago for analysis.
The analysis of 1 346 objects collected in three beach surveys (plastics, glass, metal, packaging and others) showed that, on average, 91% of them were made up of plastic material and synthetic fibres. From these samples it was possible to identify trademarks from Japan, Russia, Germany, England, Poland, Argentina, Norway, China and Brazil.
It is believed that this debris comes from different fishing areas (FAO Areas 48, 58 and 88), including areas in the South Atlantic, and it is estimated that a considerable amount of marine debris remains adrift in the Southern Ocean. Some of this debris is already causing damage, not only to fur seals but also to birds nesting at Cape Shirreff.
It is recommended that Parties to the Antarctic System Treaty, a) take action to reinforce MARPOL 73/78, encouraging those who have not yet signed the Convention to take steps to do so, and b) to establish a monitoring network around Antarctica and its islands, to assess whether this problem is increasing or decreasing and monitor its adverse effects on Antarctic marine biota.