CCAMLR

When considering establishment of MPAs, a set of criteria to properly evaluate proposals is necessary and essential to streamline and facilitate examinations.  On the basis of the discussions at the last Commission meeting, Japan is planning to propose a resolution “Standardized Procedure to Establish CCAMLR MPAs in accordance with the Conservation Measure 91-04”, hoping to contribute to constructive discussions thereon at the Commission meeting in 2014, in order for CCAMLR’s efficient and effective achievements in its leading work towards proper establishment of MPAs on the high seas.

We are submitting this paper to the WG-EMM meeting, which has competence on area management including MPA matters, in order to inform the CCAMLR members of our intention and expect to have initial inputs from the members to start dialogue.

Top predators are useful ecological indicators of changes in marine prey stocks and other ecosystem drivers. In the Ross Sea region, most south polar skuas (Catharacta maccormicki) nest near Adélie penguin (Pygoscelis adeliae) colonies, feeding on fish, penguin eggs and chicks, and carrion. We estimated skua abundance at Adélie penguin colonies on Ross Island in two consecutive years and tested for a relationship between these estimates and penguin colony sizes. We used distance sampling to estimate numbers of skuas and skua breeding pairs (based on nests), at five penguin nesting areas of varying size within the three main Ross Island colonies. We considered skua populations in ice-free areas within 500-m buffers around penguin sub-colonies at Cape Bird and within 1000 m at Cape Crozier and Cape Royds, where skuas were more widely dispersed. Estimated skua numbers were highest at Cape Crozier (4054–4892 individuals) and lowest at Cape Royds (141–152). Comparison with our skua breeding population estimates suggested that most skuas at these locations were breeding or attempting to breed. We found a strong log-log linear relationship between numbers of skuas and penguin breeding pairs. Many historical paired estimates of skua numbers and penguin colony sizes in the Ross Sea fell below this regression line. We probably overestimated skua numbers at some colonies by overestimating the areas that skuas occupied. Applying our regression model to published mean Adélie penguin colony sizes at 23 locations predicted 18 000 skuas (9 000 breeding pairs) total in the western Ross Sea, which is also likely an overestimate. We plan to revise our estimates and regression model by redefining the areas surveyed and recalculating abundances. We propose to validate the model by surveying skuas at a subset of Adélie penguin colonies. The revised, validated skua population estimate can then inform ecosystem models applied to fisheries management in the Ross Sea.

Software has been written to enable semi-automated census counting and count validation of nesting Adélie penguins (Pygoscelis adeliae), on aerial photographs of the Ross Sea sector of Antarctica. The software is written in MATLAB^®, is freely available and is deployed to users as a graphical user interface program. Previously, this task had been accomplished by manual marking of printed images, which is slow, and highly-dependent on the skill of the operator. The basis of the semi-automated counting procedure is linear discriminant analysis to separate the background (snow, water, rock, bare ground) from the guano-covered colony area, followed by morphological image processing operators to select the breeding penguins within the colony. Interactive features are provided in the software that allow an operator to add penguins omitted in the pattern recognition process, delete falsely-detected breeding penguins singly or in groups, selectively process a defined area, and record the running census counts. Validation of the counts against an experienced human counter is assisted by facilities to randomly sample the counted penguins, provide corrections to the census, and estimate the uncertainty of the counting process. The software has also been extended to allow for efficient counting of nesting Adélie penguins, although not automated pattern recognition, from historical black-and-white medium-format transparencies. We propose that our census software has much wider applicability than just counting penguins. While the present software has been written specifically for census counts of breeding Adélie penguins, there is no reason why the present approach could not be used for census counts of other species, such as seals on ice or farm animals on pasture. We outline the extent to which this software approach can be used with other species, and to aid the accuracy and reliability of count estimates from moderate-resolution satellite imagery.

The Antarctic Treaty area will become increasingly frequented by both researchers and tourists in the future. Three main areas are likely to be impacted by this increase in use and by alterations due to climate change: the Western Antarctic Peninsula, the Ross Sea, and coastal regions of East Antarctica. From previous reports we know that penguin species are highly susceptible to a number of infectious diseases. The number of investigations into infectious diseases of penguins has continued to increase over the last 50 years.  However, issues of data not being published and a lack of formal risk assessment regarding the introduction or transfer of infectious disease agents within the Antarctic Treaty System, means that our understanding is still patchy. A feather loss condition of unknown etiology, potentially due to an infectious agent, is affecting Adélie penguins (Pygoscelis adeliae) on Ross Island. This requires urgent further investigation. Also of concern, is that a number of mass mortality events have occurred. The majority of these events have occurred since the year 2000 in regions that will likely be affected by climate change and increased human activity.

As long-lived seabirds, Adélie penguins are valuable as indicators of the status of marine ecosystem health and are an indicator-species used in the CEMP program. One understudied aspect of penguin biology, however, is the effect of infectious diseases on these birds.  Long-term disease studies would therefore be useful as an adjunct to aid in identifying anthropogenic threats to ecosystem health within the Antarctic Treaty area.

For the above reasons, we recommend CCAMLR establish a health/disease monitoring program (including designated control sites and compilation of disease datasets) for Adélie penguins in the Western Antarctic Peninsula, the Ross Sea, and coastal regions of East Antarctica. We propose possible steps towards the goal of establishing baseline data and tracking infectious diseases in Adélie penguins, with the anticipated further increase in human activity and environmental changes in the Antarctic in mind.  This information could then be used by CCAMLR to help inform management decisions.

Weddell seals (Leptonychotes weddellii) and killer whales (Orcinus orca), specifically Type C killer whales (TCKW), have been identified as the top predators most likely to be directly affected by the removal of Antarctic toothfish (Dissostichus mawsoni; ‘toothfish’) in the Ross Sea region.  However, extreme paucity of information about the diet of TCKW, and uncertainty regarding the degree of reliance on toothfish as a critical prey item, have limited our ability to (a) assess the risk posed by the fishery to TCKW and other marine mammals and (b) mitigate potential risk by implementation of management strategies such as closures to protect key foraging habitats. During late January 2014, feeding by TCKW was recorded during 5 of 8 helicopter flights.  For 3 of these observations, the prey was identifiable as toothfish parts; no consumption of non-fish prey by TCKW was detected.  We also observed a large number of TCKW with small and presumably suckling calves.  Given that lactation represents a significant energy cost, we calculated energy expenditures of adult TCKW during maintenance, late-stage gestation, and lactation.  A comparison of energy expenditure with energy densities of fish prey indicates that available fish other than toothfish are insufficient to support the increased energetic costs of lactation.  This conclusion holds even assuming unlimited access to prey and without considering the energy cost of foraging (CPUE).  Marine mammals and birds contain more energy than fish prey, but re-orientation of TCKW towards non-fish prey would represent a major behavioural modification of unknown probability. A dependence of lactating TCKW on toothfish to support the additional cost of milk production implies a strong trophic dependency even if limited to a relatively brief period of the year.  We conclude that there is a probable risk to TCKW if there was a reduction in the availability of toothfish during the lactation period.  Further information on this dependency, including to what extent it has clear spatial or seasonal demarcation, is urgently required.

To explore the potential effects of the toothfish fishery on the population dynamics of Antarctic toothfish and its main prey, grenadiers (Macrouridae) and icefish (Channichthyidae), we develop a spatially explicit model using a predator-prey suitability model for the Ross Sea Region. We model the age-based population dynamics of toothfish, grenadier, and icefish, and include natural mortality (M1) and predation mortality (M2), in addition to fishing mortality (F) on all three species. The model suggests that the predation release caused by the fishery effect on toothfish abundance is greater than the direct fishing mortality on both prey species and that icefish is expected to show a larger increase in biomass through time than grenadiers. It also suggests that a prey-suitability function is more likely than a Holling type II function to describe the predatory relationships in the model. We use the model to compare the predicted population changes with available abundance data for each species to develop hypotheses of the nature of the interaction. Whilst this model is in a development stage, it provides a useful tool for evaluating potential impacts of the fishery on key prey species, and for assessing and designing monitoring tools for fish species associated with the toothfish fishery. We recommend targeted sampling of toothfish for diet analysis, and the monitoring of icefish and grenadier populations in SSRUs 88.1H and 88.1K through the development of age frequencies (length measurements and aging).

Stable isotopes of carbon and nitrogen (δ¹⁵N and δ¹³C) in Antarctic toothfish (Dissostichus mawsoni) muscle were measured to study the trophic connections of Antarctic toothfish in the Ross and Amundsen Sea regions (CCAMLR Subareas 88.1 and SSRU 88.2H respectively). More than 1700 toothfish were sampled by scientific observers on New Zealand vessels between 2005/06 and 2013/14. More than 100 samples each of four by-catch species (grenadiers, icefish, moray cods and deep-sea cod) were also analysed, but only from the Ross Sea region. Appropriate corrections were made to account for the effect of lipid in muscle on δ¹³C in a way that did not compromise the accuracy of δ¹⁵N measurements. We found considerable variability in δ¹⁵N and δ¹³C of toothfish that were not explained by fish length, sex, location, depth or year of capture. We found statistically significant but small relationships between δ¹⁵N and fish length, region, and year: (1) on average, larger toothfish fed on prey of higher trophic level; (2) δ¹⁵N values of toothfish on the Ross Sea slope were lower (~0.8‰ between medians) than in other areas (northern Ross Sea seamounts, Ross Sea shelf and 88.2H); (3) after allowing for fish length, sex, and location, there was a small but significant reduction in δ¹⁵N values (0.3‰) between 2010 and 2014. This study found that δ¹³C values of toothfish in the Amundsen Sea region were substantially higher than in the Ross Sea region (medians differed by 1.4‰). This result implies that most of toothfish sampled from the Amundsen Sea had not mixed with fish from the Ross Sea region for the 6 months – 2 years before capture (the likely turnover time of protein in fish muscle). The result is consistent with different spawning populations in the two regions. In the north and slope areas of the Ross Sea, “prey polygons” were used to investigate whether δ¹⁵N and δ¹³C values for toothfish were consistent with isotope values for the likely main prey species, assuming standard trophic fractionation factors. For the Ross Sea slope region, the predator-prey polygon largely enclosed the toothfish isotope values, indicating that the by-catch species caught the same area could have comprised most of the toothfish diet. However, the predator and prey isotope data were inconsistent for the northern seamount region because δ¹³C for by-catch species were higher in the north than the slope area of the Ross Sea, but δ¹³C for toothfish were similar in the two areas. The reason for this difference is as yet unclear but is consistent with toothfish feeding at a low rate in the northern Ross Sea area and staying there for less than a year.

In previous years we revealed that period 2006-2011 is characterized by the highest values of standardized CPUE indices in the Subarea 48.1 for the last 25 years. We continue to investigate krill fishery data for understanding reasons of this ‘high CPUE’ regime. The authors present the analysis of spatial - temporal variability of krill fishery based on CPUE trends, trawling duration, catch per haul, fishing efforts (hours fished) and vessel locations for traditional and continuous fishing methods. Our investigation shows how fishery operated by years and month in each SSMUs with special attention to differences between national fleets. It was shown also significant variability in fishing indices based on different fishing methods as well as between national fleets using traditional fishing method.

We obtained the additional evidence that ‘high CPUE’ regime’ in 2006-2011 is not associated with the changes in fishing methods but is result of the influence of changing environment. Impact of fishing methods on fleet locations was not revealed also.    

Our opinion is that climate changes can become the reason for the changes in sea ice locations and krill abundance and distribution affecting fishery strategy and performance. The important evidence of above said is the СPUE regimes switching observed in long-term fishery.

We suggest that information on variability of krill fishable biomass distribution in connection to the fishery performance will promote important platform for developing feedback management procedures for krill fishery in Subarea 48.1 as well as in Area 48. The source of this information should be acoustic surveys and observations onboard krill fishing vessels.

A National Workshop on CCAMLR MPAs was conducted at Valparaiso, Chile, 13-14 May 2014. Main points discussed were the significance of each conservation objective for the process, the best way to implement each objective in the analysis and data gaps. Outputs of the workshop are expected to contribute to the general discussion on MPA planning for Domain 1.

Presented Annex 21-03/A as required by Conservation Measure 21-03 with set nets configuration and scheme of marine mammal exclusion device.