CCAMLR

The Generalised Yield Model was used to estimate fishing mortality and spawning stock biomass reference points for the krill fishery in CCAMLR Area 48 consistent with the catch trigger level of 620,000 tonnes. Projections were run with various increased levels of recruitment variability to analyse the sensitivity of the estimates of the reference points to recruitment variability.
The estimates of F and SSB reference points for the krill stock in Area 48 consistent with the catch trigger level are 0.0159 (95 % CIs: 0.00750 – 0.0357) and 97.7 % SSB0 (80 % CIs: 71.6 – 135 %) respectively. In comparison, the F and SSB reference points for the precautionary catch limit of 5.61 million tonnes are 0.186 (95 % CIs: 0.0762 – 0.630) and 75.0 % (47.9 – 113 %) respectively.
The probability of stock depletion increases substantially with increased recruitment variability, though in absolute terms remains negligible. The uncertainty surrounding median estimates of F and SSB reference points for the catch trigger level increases with increased variability in recruitment, though the median estimates are unaffected.

The model terminated prematurely with a 40% increase in recruitment proportion SD. It is likely that this is due to a design feature of the Generalised Yield Model in place to prevent projections from running with potentially significant bias in projected recruitment resulting from poor parameterisation of the beta function.

During April 2011, a multi-national group of scientists with expertise on Antarctic krill Euphausia superba and environmental sciences attended a workshop aiming to evaluate new knowledge on the impact of climate change and increasing fisheries on Antarctic krill and Antarctic ecosystems, and possible repercussions for resource management. The workshop was organised by the Institute of Marine Resources and Ecosystem Studies (IMARES) in the Netherlands, and funded by the European Commission and the Dutch government. The scientific evaluation focused on major agents of climate change, such as ocean warming, sea ice loss, and ocean acidification. It was concluded that the cumulative impact of climate change on krill is probably negative. To be able to account for climate change-induced ramifications on Antarctic krill and ecosystems, the adaptive capacity of the fisheries management of CCAMLR must be enhanced. To achieve this, critical knowledge gaps in the biology and ecology of Antarctic krill need to be closed. Research needs to be intensified on recruitment processes in Antarctic krill, under-ice and benthic habitat use, their capacity to adapt to environmental change, their ecosystem function, as well as the energy demand and food consumption of krill-dependent predators. With respect to CCAMLR’s ecosystem-based management approach, several recommendations were agreed on during the workshop. In particular, it was concluded that current precautionary management measures need to be maintained, until sufficient knowledge exists about the population levels of sustainability. It was further agreed that increasing the efficiency of CEMP is fundamental for a solid science-based management of the fishery.

Two successful experiments on definition of Antarctic krill mortality have been carried out aboard Polish vessel Dalmor II according to the pattern submitted in paper SC-CAMLR-XXVIII/BG/10. Approximately 230 to 130 kg of krill are percolated and punched through per an hour of trawling if the average catch per an hour of trawling is about 8 tons and towing speed is 2.6-2.7 knots. The key parameters of trawling which influence the value of the Antarctic krill mortality rate are: the trawl configuration and the mesh size of its segments; the speed of the vessel and the towing duration.

Combination of conventional and continuous techniques during krill fishery at the Russian commercial vessel "Maxim Starostin" allowed to compare the size structure of the Antarctic krill (Euphausia superba) caught by these two techniques. Results of comparison are discussed in relation to the selectivity of fishing gears and the space-time variability of krill. Differences between size composition of krill caught by conventional and continuous techniques of fishery which could be connect with the trawls selectivity weren’t found. At the same time results of the analysis didn’t indicate that there were no differences between selectivity of conventional and continuous trawls. We assume that the possible influence of differences between selectivity of fishing gears were exceeded by significant space-time variability of Antarctic krill.

A krill net sampling survey was carried out west of the Antarctic Peninsula in January 2011 to collect data on krill distribution, abundance, demography, spawning and recruitment success. The survey was a joint German and US effort. While the US AMLR Survey section covered the area between Elephant Island and the western entrance of Bransfield Strait, the “Polarstern” survey grid followed back to back and extended southwest beyond Adelaide Island/Marguerite Bay. 177 quantitative net samples were taken and analyzed for post-larval and larval krill, Euphausia superba, as well as for salps, Salpa thompsoni.

The results of this survey represent the most complete picture of the spatial distribution of krill abundance, demography, and production on the western side of the Antarctic Peninsula conducted since the late 1980s.

Automated camera systems deployed at Adélie penguin breeding colonies provide daily measurements that allow high resolution temporal availability functions to be estimated, which in turn can be used to correct population estimates for availability bias. However, such frequent data are time consuming and expensive to process, and it is of interest to determine if such data could be subsampled with significant loss of information content. To this end, a simulation study was undertaken to examine how the frequency of sampling attendance at Adélie penguin breeding colonies would affect models of attendance for correcting population counts for potential attendance bias. Generalised additive models of simulated time-series were shown to adequately recover known structure for sampling periodicities up to five days. Most precise estimates of attendance ratios to correct non-optimal population counts for availability bias are obtained from higher frequency sampling, with a trade-off observed between sampling frequency and precision. Subsampling at periodicities of six days or greater did not adequately recover known simulated model structure and cannot be recommended.

This paper presents a time series of relevant data reported from scientific observations in the CCAMLR krill fishery: 1999/2000 to 2009/10.

Dense assemblages of hyocrinid stalked crinoids (Echinodermata, Crinoidea, Hyocrinidae,) a vulnerable marine ecosystem (VME) indicator taxon, were encountered at four sites on two isolated knolls adjacent to the northwest and southeast of Admiralty Seamount (CCAMLR Subarea 88.1G) at 578-778 m depths. The details of these encounters, utilizing occurrence and density from underwater video transects, are provided. As a precautionary measure, two boxes around these respective knolls are proposed for designation as VMEs, and inclusion into the CCAMLR VME registry. These boxes are approximately 19.7 and 19.6 km2. This proposal is structured according to the guidelines set out in Conservation Measure 22-06 (2010), ANNEX 22-06/B, and provides published supporting documentation (Bowden et al, 2011; Appendix 1).

Six Members submitted notifications for a total 15 vessels for krill fisheries in Subareas 48.1, 48.2, 48.3 and 48.4 in 2011/12, and the total notified, expected level of catch of krill is 391,000 tonnes. There was no notification submitted for exploratory fisheries for krill in 2011/12.

The requirements for notifying encounters, and potential encounters with vulnerable marine ecosystems (VMEs) are described in Conservation Measures (CM). Notifications are made under CM 22-07 in the case of encounters with potential VMEs during the course of bottom fishing, and under CM 22-06 in other cases such as during research surveys. Notifications are held in the Secretariat’s VME registry.

Since 2008, the Secretariat has received a total of 32 notifications of encounters with VMEs arising from research surveys (CM 22-06): 17 notifications in Subarea 48.1; 13 notifications in Subarea 48.2; and 2 notifications in Division 58.4.1. No notification has been submitted to the Secretariat so far in 2010/11; however a notification for two VMEs in the Ross Sea has been submitted to WG-EMM for consideration (WG-EMM-11/10).

Since 2008, the Secretariat has also received a total of 112 VME-indicator notifications from exploratory bottom fisheries (CM 22-07): 29 in 2008/09; 24 in 2009/10; and 59 so far in 2010/11. These notifications originated from vessels operating in the exploratory crab fishery in Subarea 48.2 (1 notification), and exploratory longline fisheries in Subareas 48.6 (2 notifications), 88.1 (90 notifications) and 88.2 (19 notifications). No notification has been made from exploratory fisheries in Divisions 58.4.1, 58.4.2, 58.4.3a and 58.4.3b.

The VME-indicator notifications has led to the declaration of 42 VME risk areas in Subarea 88.1 and 4 risk areas in Subarea 88.2. In addition, 5 VME fine-scale rectangles were identified in Subarea 88.1 and 1 VME fine-scale rectangle was identified in Subarea 88.2