CCAMLR

The development of methods to estimate unaccounted fishing mortality from lost fishing lines requires an estimate of the number of lost hooks that are attached to sections of line. In 2011 hook loss data was provided by 21 of the 34 vessel/fishery reports with an estimated 317920 hooks lost attached to sections of lines.  In 2012 15 of the 26 vessel/fishery reports provided non-zero data with an estimated total of 313548 hooks lost attached to sections of line. In exploratory fisheries, particularly those in data-poor regions, the requirement and appropriate mechanism for reporting these data may need to be reiterated in order to achieve a greater level of engagement with the requirements to complete the C2 data reporting form.

In 2012 data on beach surveys, debris associated with seabird colonies, marine mammal entanglements and hydrocarbon soilings were received from South Africa, the United Kingdom, and Uruguay.  Non-fishing items such as plastics, packaging materials and wood remain the most common type of debris items found in beach surveys.  The fishing items found were mostly from longline and trawl origins. Plastic packaging bands continue to be found in beach surveys, however, for the first time since these surveys originated in 2002 there have been no closed bands found at any of the three sites.  The amount of debris in colonies of grey-headed albatrosses, wandering albatrosses and black-browed albatrosses at Bird Island decreased significantly since 2011, with the major category of items found being plastics.  The amount of fishing related items (fishing lines and hooks) found in wandering albatross colonies remains the foremost debris item found in each season. The number of marine mammal entanglements decreased since 2011 with packaging bands and fishing gear the main entangling materials. There was only one new hydrocarbon soiling reported from King Edward Point in 2010.   The results of the ongoing monitoring of marine debris in the Convention Area suggest that while the type and amount of debris varies from annually there have been no long-term trends over the past decade.  Extrapolation of these findings to areas outside Area 48 are limited by data on long-term monitoring of marine debris and Members with opportunities to engage in such monitoring are encouraged to submit data to the Secretariat.

Since its inception in 1992 the CCAMLR Scheme of International Scientific Observation  the complexity of documenting procedures, variety of sampling requirements and associated data management have all increased. Given  the likely continued increase in complexity it is essential to have processes in place to review, revise and adapt existing procedures to ensure that the scheme overall remains robust.   This is a scoping paper to initiate discussion on a task group with representation from all interested parties (including WG-FSA, WG-EMM, WG-IMAF and SCIC) to review observer sampling requirements across all fishing sectors and conservation measures.

This paper has been provided by the Secretariat to assist WG-FSA and the Scientific Committee to give additional consideration, at their 2012 meetings, to methods to estimate trends in IUU fishing and estimates of IUU catches, including further consideration of the recommendations of JAG.  The paper includes:

1. consideration of patterns and activities associated with IUU fishing in the CAMLR Convention Area
2. the methodology used in estimating IUU catches and trends in the CAMLR Convention Area
3. a program of work for consideration aimed at improving the quality of information available to estimate IUU fishing trends and catches in the CAMLR Convention Area.

This paper summarises fishery-related scientific research notified under Conservation Measure 24-01 for 2011/12 and 2012/13.

This paper presents an analysis prepared by the  Secretariat and Korea to provide the context to the more variable and anomalously high CPUEs of the two Korean ships the Insung No. 2 and the Insung No. 7 while participating in CCAMLR exploratory fisheries. The operational characteristics of these ships showed distinct differences to the other ships that have participated in longline toothfish fisheries in Divisions 58.4.1, 58.4.2 and subarea 48.6. These differences are reflected in CPUEs with large mean and high variability, arising from periods of repeated low/zero catches and highly spatially and temporally aggregated sets with the largest catches reported across the fleet.

To infer important prey resources for Antarctic toothfish (Dissostichus mawsoni) in the south of SSRUs 881.J and 881.L in the southern Ross Sea, their lipid composition was determined and compared tolipid profiles of fish and invertebrate species taken as bycatch in the fishery or collected from stomachs of toothfish. Stable carbon and nitrogen isotope ratios were also determined to further identify feeding relationships between these species. The aim of this study was to establish the feasibility of tracking main dietary items of pre-recruit Antarctic toothfish by comparing results of biomarker analysis and conventional diet analysis. Sampling collections were made during a longline survey of pre-recruit toothfish from research vessel in February 2012. Results of fatty acid (FA) and stable isotope analyses from this study provide evidence that a combination of these two techniques can delineate the main prey items of Antarctic toothfish and trophic structure of the toothfish-related fish food web in the southern Ross Sea ecosystem. Similarities in total FA compositions and the FA profiles in muscle tissue of Antarctic toothfish and Pleuragramma antarctica, Pogonophryne barsukovi, Dacodraco hunteri, and Trematomus loennbergii indicated a trophic connection between toothfish and these fish species. Meanδ¹⁵N values of Antarctic toothfish were higher than those of P. antarcticum, P. barsukovi, and T. loennbergii, indicating a higher trophic position of thetoothfish. In contrast, similar δ¹⁵N values between Antarctic toothfish and icefish (D. hunteri) suggested that they occupy the same trophic position. Overall results of this survey are consistent with the frequency and percentage occurrence of prey in Antarctic toothfish stomachs. Further collection and subsequent biomarker analyses for more pelagic and benthic biota are needed to better understand entire food web structure in the southern Ross Sea.

The research fishing proposal for Dissostichus spp. in Subarea 48.6 and Divisions 58.4.1, 58.4.2 and 58.4.3a is resubmitted following paragraph 3.24 of WG-SAM-12. In the present proposal, we firstly showed information of catch, efforts, tagging experimental results based on the CCAMLR C2 data, and secondly showed the results of biological features with some discussion of life history in data-poor fisheries mainly using CCAMLR Biological data. Finally we made the proposal for the operations in the 2012/13 season for all vessels.

Catch and efforts were active in two areas in the north of Subarea 48.6, two areas in the south of Subarea 48.6, one area in Division 58.4.2, five areas in Division 58.4.1 and one area in Division 58.4.3a. In these areas, number of tags available for recaptures in 2013 was also higher. Recaptures were made also within these areas but those for D. mawsoni were scarce, especially in Division 58.4.2. Nominal CPUE in terms of weight of D. mawsoni in the south of Subarea 48.6 is two times higher than those in other areas.

According to the distribution of CPUE for small size groups, the west of Prydz Bay region seemed to be an important area for pre-adult D.mawsoni as reported previously. From the seasonal variations in development of GSI, the north of Subarea 48.6 is one of important spawning grounds for D. mawsoni, however, self-sustaining population may not exist in these areas because of very small proportion of immature fish. Highest GSI for D. mawsoni in March over years was observed in the shelf area at approximately 100°E (SSRU 58.4.1 C), which is consistent with previous report. The increase in abundance of fish with small sizes in SSRUs B and C of the south of Subarea 48.6 speculated the extension of the Weddell Sea population. The clarification of life history in data-poor fisheries may need more information of biological features in the wide areas including Weddle Sea and Ross Sea regions.

From the number of tags available for recaptures, a total of 12 blocks (aggregation of 1° longitude x 30’ latitude box) for research is produced over the data-poor fisheries area for all vessels. The research should be fundamentally conducted within the blocks. However, in case research hauls in the blocks along the ice-shelf area cannot be done sufficiently due to sea-ice and small number of fish caught etc., the vessel may operate at neighboring available area and accumulate tagged and released fish to clarify the migration of fish, biological feasters such as distribution of developmental and maturity stages, sex ratio, age-length relationship, and catch rate which help the progress in assessment of stock status.

Estimations on expected numbers of recaptures suggested that the increase of current catch limits may be needed to increase in success of the mark recapture research for D. mawsoni in the south of Subarea 48.6 and Divisions 58.4.1 and 58.4.2.

Following the advice from the CCAMLR Working Group in WG-SAM in 2012, a preliminary assessment of stock status of D. eleginoides in SSRU C in Ob-Lena Banks was made using a CASAL catch-at-length model. In this preliminary assessment, the model was started in 1990 and catch, proportions at length in the catch, and recapture data from SSRU C from 2007/08 to 2011/12 were fitted in the model. The MPD estimate of B₀ was 741 tonnes, and current biomass was 625 tonnes (84.4 % of B₀). MPD fits suggest suitable fits to the data, however, there appears to be a pattern of increasing YCS over the time, which is unlikely. Therefore, model where all of the YCS are fixed at 1 should be considered next time. MCMC plots and diagnostics suggest low mixing of the MCMC chain. Hence, the MCMC results are not yet robust. The reasons for this need to be investigated, and may require that the chain will need to be run for much longer (e.g. 10e6 iterations), and subsampled less frequently. The MCMC estimate of B₀ was 1 455 tonnes, and current biomass was 1 275 tonnes (87.6 % of B₀). An additional uncertainty in the current model is the historical IUU catch. The current model only includes the catch history since 2007/08 but there is a history of IUU catches for the whole Division starting from 1996/97. To provide a more realistic B₀ to consider the inclusion of IUU catches for this SSRU into the model. Possible approaches for this should be discussed during WG-FSA-2012.