The current season (2014/15) is the final one of the first three-season research which began in 2013 in data-poor fisheries. In the present report, catch, effort and biological data recorded by all effective vessels were analyzed for the improvement of stock assessment in the research blocks. Based on the result, the next three-season (2016-18) research plan in Division 58.4.1 is also presented.

The stock sizes for five research blocks (58.4.1_1, 58.4.1_2, 58.4.1_3, 58.4.1_4 and 58.4.1_5) were estimated by the Petersen estimator and the CPUE x seabed analogy method using updated CCAMLR C2 data and reference area sizes.

Although no toothfish fishery data along the shelf area in austral autumn – winter was available, SSRU 58.4.1 C may be also one of the important spawning grounds for D. mawsoni from the degrees in development of GSI in summer comparable with those in the north of Subarea 48.6 and Banzare Bank.

Understanding of the resource structure through clarification of their life history is essential to establish stock assessment and robust stock/ fisheries management of Dissostichus spp. population(s) in data- poor exploratory fisheries. During the second three-season research, we will continue enhanced tagging program, and collection and analysis of biological data including otoliths and gonads to clarify migration route and associated life stages of the fish.

To this end, we propose to follow the current research style in the current research blocks for the second three-season research with the sample sizes estimated following the procedure recommended at the WG-FSA in 2013 in order to maximize the expectation of tag-recapture to the extent possible under the precautionary exploitation rate.

The current season (2014/15) is the final one of the first three-season research which began in 2013 in data-poor fisheries. In the present report, catch, effort and biological data recorded by all effective vessels were analyzed for the improvement of stock assessment in the research blocks. Based on the result, the next three-season (2016-18) research plan in Division 58.4.2 is also presented.

The stock sizes for a research block (58.4.2_1) were estimated by the Petersen estimator and the CPUE x seabed analogy method using updated CCAMLR C2 data and reference area sizes.

The occurrence of juvenile fish for each ice shelf block suggests that the recruitment occurs along the ice-shelf zones of Subarea 58.4.2, especially SSRUs 58.4.2C and 58.4.2D. The GSIs during the austral summer over years tend to be more progressed in SSRU 58.4.2A.

Understanding of the resource structure through clarification of their life history is essential to establish stock assessment and robust stock/ fisheries management of Dissostichus spp. population(s) in data- poor exploratory fisheries. During the second three-season research, we will continue enhanced tagging program, and collection and analysis of biological data including otoliths and gonads to clarify migration route and associated life stages of the fish.

To this end, we propose to follow the current research style in the current research blocks for the second three-season research with the sample sizes estimated following the procedure recommended at the WG-FSA in 2013 in order to maximize the expectation of tag-recapture to the extent possible under the precautionary exploitation rate.

The current season (2014/15) is the final one of the first three-season research which began in 2013 in data-poor fisheries. In the present report, catch, effort and biological data recorded by all effective vessels were analyzed for the improvement of stock assessment in the research blocks. Based on the result, the next three-season (2016-18) research plan in Division 58.4.3a is also presented.

The stock sizes for block 58.4.3a_1 was estimated by the Petersen estimator and the CPUE x seabed analogy method using updated CCAMLR C2 data and reference area sizes. The stock size using the Petersen estimator was largely different from that using the CPUE method. Predicted numbers of tag recaptures from the estimated stock sizes using those methods were generally inconsistent with the observed number during 2013-14 seasons.

Understanding of the resource structure through clarification of their life history is essential to establish stock assessment and robust stock/ fisheries management of Dissostichus spp. population(s) in data- poor exploratory fisheries. During the second three-season research, we will continue enhanced tagging program, and collection and analysis of biological data including otoliths and gonads to clarify migration route and associated life stages of the fish.

To this end, we propose to follow the current research style in the current research blocks for the second three-season research with the sample sizes estimated following the procedure recommended at the WG-FSA in 2013 in order to maximize the expectation of tag-recapture to the extent possible under the precautionary exploitation rate.