Exploratory fishing for toothfish (Dissostichus spp.) in East Antarctica (Divisions 58.4.1 and 58.4.2) began in 2003. Robust stock assessment and catch limits according to CCAMLR decision rules remain to be determined for these Divisions. The 2015/16 season was the first of a three-year research plan which was developed by Australia (WG-FSA-15/47 Rev. 1) under Conservation Measure 41–01. Australia will present to WG-SAM-2016 a full report on the fishing operation, catch composition, tagging and biological sampling undertaken by Australia during 2015/16 in SSRUs 58.4.1E and 58.4.1G. Here, we evaluate the original research plan set out in WG-FSA-15/47 Rev. 1, and propose continuation of this research in the 2016/17 season. Ongoing standardised longline fishing, in conjunction with fish biological measurements, tagging and aging, will be used to develop a stock assessment/s for Divisions 58.4.1 and 58.4.2, and inform the necessary considerations of spatial structure, biomass and connectivity of toothfish populations. In addition, environmental data from CTD (conductivity, temperature and depth) and video loggers will contribute to models of toothfish habitat use. These models will inform spatial management approaches for toothfish, and the conservation of representative areas of benthic biodiversity. Additional outcomes include mapping of the bathymetry of fishable areas, and improved understanding of the distribution, relative abundance, and life histories of bycatch species.
Presentar antecedentes y el objetivo de contribuir con un barco mas en la pesca de investigación en la Subárea 48.6 que aumentaria las chances de cuota de pesca de investigación y asi el número de peces observados y marcados, a efectos de lograr un nivel que permita robustecer el tamaño del stock estimado. Este documento presenta un Plan de investigación para el período 2016/17 - 2018/19, en el marco de la Medida de Conservación 41-04.
Abstract:
The current season (2015/16) is the first one of the second three-season research in data-poor fisheries. In the present report, the next season research plan in Division 58.4.2 was made using the updated CCAMLR C2 and Observer data.
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.
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 next 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.
