CCAMLR

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

The CCAMLR Ecosystem Monitoring Program (CEMP) uses indices derived from data on indicator species collected by standard methods in the three Integrated Study Regions of the Convention Area. Each year the Secretariat updates the standardised index values and provides a summary of trends and anomalies in these data. This report covers biological indices only.

Six Members submitted data for 13 sites and 12 CEMP parameters in 2010/11. No data was received from CEMP sites in Area 88. Since 1989/90, a total of 116 anomalous values (anomalies, see Appendix 1) have been observed in the times series of biological indices. All anomalies (both high and low) in the past 2 seasons have been from monitoring sites in Subarea 48.1. These are:

2009/10:

• Low number of chicks fledged per egg laid (A6a) for Adelie penguins at Stranger Point Station;
• Low chick fledgling weight (A7) for Adelie penguins at Admiralty Bay; and
• High pup growth rate deviate (C2b) for female Antarctic fur seals at Cape Shirreff.

2010/11:

• High fledging weight (A7) for Gentoo penguins at Cape Shirreff;
• Low stomach contents weight (A8a) for Gentoo penguins at Admiralty Bay;
• Low occurrence of fish in diet (A8c) for Gentoo penguins at Admiralty Bay.

So far this season (2010/11), twelve vessels from Chile, China, Japan, Korea, Norway and Poland have fished for krill in Area 48. The total catch reported to May 2011 was 110949 t, most of which has been taken from Subarea 48.2 between February and May. Approximately 55% of the catch has been taken by two vessels using the continuous fishing system. The forecast total catch of krill for the season falls in the range 153000-214000 t. In 2009/10, 10 vessels fished for krill in Area 48 and reported a total catch of 211974 t; three vessels used the continuous fishing system. For the first time, the catches of krill approached the apportioned limit for Subarea 48.1 (25% of the trigger level: 155000 t) and the subarea was closed to krill fishing during the remainder of the season on 10 October 2010 (153262 t). A total of 85764 t of krill was taken from SSMU APBSW (Antarctic Peninsula Bransfield Straight West), 37650 t from APBSE (Antarctic Peninsula Bransfield Straight East) and 17295 t from APDPW (Antarctic Peninsula Drake Passage West). The remainder of the catch for that season was taken predominantly in Subarea 48.2, notably 48444 t from SOW (South Orkney West). The catches of krill reported from SSMUs APBSE, APBSW and APW in 2009/10 were the highest catches reported from those SSMUs in the history of the fishery. The daily catching capacity of vessels in the fishery has increased markedly since 2003/04, with vessels using conventional trawls now capable of catching and processing up to 450 t of krill per day, and some vessels using the continuous fishing system have recently exceeded 900 t of krill per day