CCAMLR

Following the recommendation of WG-FSA in 2014 the Secretariat has undertaken an analysis of bycatch in CCAMLR longline fisheries. The numerical target catch ratio (the number of target fish as a proportion of the total number of fish caught), using haul by haul data from the Ross Sea toothfish fishery from 2008 – 2014, was used as a single metric to examine the amount of bycatch reported by vessels. This analysis indicated that, as expected, differences in this index arose due to gear and location of fishing. However, there was also evidence of distinct differences in the mean (and distribution) in the index from two groups of Members flagged vessels, that together contribute 84% of the haul by haul data. These differences do not appear to be explained by differences in gear or location and are also apparent in the data reported by observers. However, the way in which observer sampling of bycatch is reported requires clarification. In order to further develop the analysis of bycatch it is essential to consider what additional factors need to be included in that analysis. This consideration should also review whether there have been any misinterpretations of the data, or the assumptions underlying the analysis, that may have led to errors in the results and subsequent interpretation. Correspondence from Members that have been active in CCAMLR longline fisheries on how the data on catch and bycatch are collected and reported is provided.

In 2014, the Scientific Committee noted that it needed to develop advice routinely on the potential impacts on dependent and related species for proposed exploratory fisheries and requested working groups consider how to report on these issues, which also form part of the review procedures under Conservation Measure 22-06 and 22-07. It requested Members to submit analyses for consideration.  Here, we present (i) a method for automating these requirements irrespective of the data layers being used, and (ii) examples on how to report rapid assessments of interactions with ecological features, using  bottom fishing on benthic habitats in East Antarctica.  The assessment method has (i) an overall process for reporting on interactions of fishing with ecological features, (ii) an automated process for determining boundaries of independent patches of each class of an ecological feature, (iii) a procedure for assessing interactions of fishing within cells of a patch, (iv) aggregate measures of interactions with classes of ecological features within reporting areas, and (v) a plotting method to support assessment of interactions.  

The investigations in March-April 2015 were conducted in subarea 48.2 by Ukrainian longliner SIMEIZ . 29 sets were completed during the survey. Altogether 157 specimens of Dissostichus mawsoni and 21 specimens of Dissostichus eleginoides were tagged.  124 otolith pairs of Dissostichus mawsoni and 87 - Dissostichus eleginoides were collected. The average sizes of  Dissostichus mawsoni  from the catches made up about 156 cm. Investigated maturity stages and stomach composition of Dissostichus spp.

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. Accordingly, a research plan has been developed under Conservation Measure 41–01 to support a proposal for an Australian vessel to participate in exploratory fishing within Divisions 58.4.1 (SSRUs C, E, G) and 58.4.2 (SSRU E). This document is identical to WG-SAM-15/10 with the exception of responses to Agenda Item No. 3.12 of the Draft Report of the WG-SAM-15 (highlighted in blue). Standardised longline fishing, in conjunction with fish biological measurements, tagging and aging, will be used to develop a stock assessment for these divisions 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.

The annual Random Stratified Trawl Survey was undertaken in Division 58.5.2 in the vicinity of Heard Island during May 2015. This paper provides a preliminary assessment of mackerel icefish population structure, abundance and yield for the area of Division 58.5.2 to the west of 79o 20’ E using standard CCAMLR methods. A large 2+ cohort is dominating the population. These projections indicate that catches of 482 t in the 2015/16 season and 357 t in the 2016/17 season.