The 2-year programme of exploratory fishing provided for by SPRFMO CMM 4.14 has been successfully completed and new and important biological information has been collected on toothfish outside the CCAMLR convention area. The key findings are that only Antarctic toothfish, Dissostichus mawsoni, were caught, that these were mostly male (~85%), and that most fish were in spawning condition or spent. These surveys provide information on the life history of Antarctic toothfish that is consistent with the current hypothesis on Antarctic toothfish growth and movement, and have provided the some of the first empirical scientific observations of spawning Antarctic toothfish. Information collected during these first two voyages will be shared with CCAMLR and had been used in the stock assessment of Antarctic toothfish in the Ross Sea region. Over the coming months, New Zealand will screen video footage and analyse all data collected in more detail than the timing of the voyages has allowed so far. In addition, to maximise the value of future data collection for both organisations’ understanding of the distribution, dynamics and status of stocks of Antarctic toothfish, New Zealand will also assess the optimum quantity and nature of data required to enable the development of a spatially-explicit integrated stock assessment model of Antarctic toothfish in the region. It is anticipated that this model, targeted for completion in 2021, will include those components of the Antarctic toothfish stock residing in the SPRFMO Area as well as in the CCAMLR Area. At this stage, it is intended that a comprehensive proposal for the future of the exploratory fishery will be presented to SPRFMO Scientific Committee in 2018.
Abstract:
The Ross Sea region has been known as an ecologically important area in the Antarctic with an extraordinary rich biota. To conserve marine living resources and the ecosystem of the Ross Sea, CCAMLR designated the area as a Marine Protected Area (MPA) at the 35th annual meetings in 2016. Since 2015, the Korean government (Ministry of Oceans and Fisheries) has been preparing to launch a research and development project (R&D) to contribute to CCAMLR’s efforts to conserve the area, and approved the budget for the said project for 5 years (2017-2022). The goal of the project is to understand the impact of climate change on the structure and function of the ecosystem of the Ross Sea region MPA. To that end, investigations on the spatial distribution of krill, biodiversity, the structure of the food web and biomagnification will be undertaken. To provide monitoring data on breeding parameters of krill-dependent species to the CCAMLR Ecosystem Monitoring Program (CEMP), investigations on population dynamics, breeding success and foraging behavior of the Adélie penguin will be conducted at Cape Hallett. Polynya dynamics, sea ice concentration and primary production will be observed in order to analyze how environmental changes affect the ecosystem. We look forward to taking a lead role in these research activities using our research infrastructure, such as the icebreaker research vessel ‘ARAON’, the air-network based on Jang Bogo Station, and the field camp at Cape Hallett.
Data on fish by-catch in the krill fishery from commercial catch data (100 153 hauls) and CCAMLR SISO data (20 766 hauls) up to 1 Sept 2017 was used to examine the frequency of occurrence, length-frequency distribution and geographic provenance of the key fish taxa reported. There is continued evidence of an increase in the data quality from the observer scheme, as well as an increase in the reporting of fish by-catch in the commercial krill fishery catch data. There was a high degree of overlap in the most frequently reported taxa in the C1 data and SISO data, with Lepidonothen larseni the most frequently reported in both datasets. The length-frequency distribution of all taxa for which >200 fish were measured had modal size class of ≤10 cm. The characteristics (species and size frequency) of fish taken as bycatch in the krill fishery are consistent with those reported in the diet of ‘krill-dependent’ predators from the region in which the krill fishery operates.
Abstract:
This paper presents an update of the metrics of capacity and capacity utilisation presented in WG-SAM 14/19 and WG-FSA 15/09 in order to monitor trends in capacity in exploratory toothfish fisheries in Subareas 88.1 and 88.2. The updated metrics show the same pattern as in previous updates and do not indicate an excess of capacity in the fishery. As previously reported, based on a measure of potential daily fishing capacity and the catch limit for an area the notified fishing capacity in some management areas compromises the ability of the Secretariat to forecast and issue a timely closure notice to reduce the possibility of an overrun using the current fishery forecasting procedure.
Abstract:
Patagonian toothfish (Dissostichus eleginoides) are found around South America from Ecuador to Uruguay, and in the sub-Antarctic and Antarctic while Antarctic toothfish (D. mawsoni) are found closer to the Antarctic continental shelf and generally south of the Polar Frontal Zone. Data from existing tagging studies indicate that both species are generally non-migratory with the majority of individuals exhibiting strong site fidelity. Between 2006–2016 there were 111 288 Patagonian toothfish tagged and released of which 10 511 (9.4%) have been recaptured; for Antarctic toothfish there have been 69 067 fish tagged and released of which 2 072 (3.0%) have been recaptured; the median distance between release and recapture was 12km (max 5 708km) and 20km (max 4 525 km) respectively. There were 210 records of Patagonian and 14 Antarctic toothfish where fish had made movements greater than 200km. Of the fish making long-distance movements 91% of D. eleginoides and 86% of D. mawsoni moved in a counter-clockwise direction around Antarctica. The low frequency of long-distance movement of toothfish between management stock units it is unlikely to adversely influence the outcomes of tag-based assessments for toothfish. However, understanding the relative scales of, and interactions between, biological populations and management stock units for toothfish is clearly important element in CCAMLR’s ecosystem-based approach to fisheries management.
The first CCAMLR Scheme of International Scientific Observation workshop (WS-SISO) was held in Buenos Aires in 2017, and discussed and agreed revisions to observer logbooks for all CCAMLR fisheries (see SC-CCAMLR-XXXVI/08). This paper summarises the proposed changes to the observer logbooks for the longline and finfish trawl fisheries, and outlines their introduction leading up the proposed adoption for the beginning of the 2019 fishing season.