CCAMLR

This report is a synthesis of mostly existing information which has been compiled for the purposes of addressing items on the FEMA 2 agenda. It summarises the management of the fishery, catch and effort, size distribution, and tagging data collected from the Antarctic toothfish fishery up to the 2007/08 fishing year. It focuses in particular on Antarctic toothfish catches taken from the continental shelf of the Ross Sea itself, because this is the area where any ecosystem effects related to predators of toothfish are most likely to occur. Of the total catch from the fishery to date of almost 19 000 t, about 20% has been taken from the northern grounds, 70% from the continental slope, and 10% from the continental shelf of the Ross Sea. The shelf catch has been taken from three quite localised fishing grounds of deep water (mainly > 800 m) off Terra Nova Bay, Ross Island, and in the south of 88.1L (adjacent to the Ross Ice Shelf). The catch rates from the exploratory longline fishery typically show high temporal and spatial variability, even between consecutive sets within the main fishing grounds. There are no reliable estimates of Antarctic toothfish abundance on the shelf at the current time. In preparing this paper we have identified some data sources which could potentially be used to estimate the abundance of toothfish on the Ross Sea shelf. However, CPUE is inherently variable both within and between seasons on the various fishing grounds and different vessels have fished different grounds in different years making interpretation difficult. Tag-recapture data from the Terra Nova Bay fishing ground would also be difficult to interpret because of the movement of tagged fish. There is also other information on the distribution of Antarctic toothfish from the area derived from other research surveys and from studies focusing on other species. US Scientists at McMurdo Sound have collected Antarctic toothfish since 1971 using vertical set lines. Their sampling has shown significant within and between season variability in catch rates. Very few Antarctic toothfish have been caught in the Ross Sea by other research sampling. Indirect observations from cameras mounted on seals shows that Antarctic toothfish at McMurdo Sound can occupy the entire water column, but the spatial and temporal extent of its midwater distribution and the proportion of the population which occurs off the bottom are unknown.

This paper provides a brief summary of progress of inter-sessional by the Sub-group on Status and Trend Assessment of Predator Populations (WG-EMM-STAPP) as a follow-up to the Predator Survey Workshop.

It is widely recognised that the interpretation of counts of penguin populations at their breeding sites during the breeding period are strongly dependent on the timing within a breeding season at which they are undertaken. While the need to adjust raw penguin count data obtained at varying times within a breeding season to minimise bias in estimates of the breeding population has long been recognised, the considerable work in obtaining one-off counts for population surveys have not been matched by the collection of adjustment data. This was recognised at the recent Predator Survey workshop, where the collection of adjustment data to improve estimation of penguin abundance was identified as a priority for future work. This paper reports on the collection and development of adjustment factor data for Adélie penguins in east Antarctica.

The first international workshop on implementing a Southern Ocean Sentinel program was held at the CCAMLR Headquarters in Hobart in April 2009. The conclusions of that workshop are provided to WG-EMM for consideration along with an overview, the program and abstracts of the keynote presentations. A report of the workshop will be submitted to the Scientific Committee for its considerations in October 2009, including discussion on the following questions: A key conclusion of the workshop was that the Sentinel program could start now with qualitative assessments of current and future climate change impacts on Southern Ocean marine ecosystems and work towards a quantitative assessment of impacts by 2014. This process will fill an important gap in current discussions on climate change impacts on marine ecosystems by the Intergovernmental Panel on Climate Change. It will also assist CCAMLR in addressing climate change impacts on the conservation of Antarctic marine living resources. Another key conclusion of the workshop is that it should be possible to identify indicators of climate change impacts in the Southern Ocean that these could be used as early warning indicators of future change in both the Southern Ocean and elsewhere in the world. Importantly for CCAMLR, work in designing such a system should be complementary with developmental work being undertaken in the CCAMLR Ecosystem Monitoring Program. CCAMLR Members are invited to participate in the qualitative and quantitative assessments of current and future climate change impacts on the Southern Ocean marine ecosystems as well participating in designing and implementing an early-warning system to identify imminent climate change impacts on global ecosystem services.

Besides the climate change impact on krill based ecosystem uncertainties the factors of the ozone distribution asymmetry influence over South Ocean is discussed. The existence of the considerable zonal asymmetry in total ozone distribution over Antarctica due to the planetary waves in a polar stratosphere is observed last decades. As was shown by authors earlier in the latitudinal interval of 55-75°S in Antarctic spring months (Sep-Nov) the minimum of quasi-stationary wave (QSW) in total ozone content distribution are continuously located over the Antarctic Peninsula and Weddell Sea area - most productive krill population region, and QSW maximum - in the Ross Sea area and Australian sector. We expect that zonal asymmetry in total ozone distribution and its long-term spatial changes should impact to South Ocean ecosystem food chain, especially in primary level. The quasi-stationary minimum in ozone distribution over north Weddell Sea area should cause the increased ultraviolet irradiation (UVR) on sea surface in comparison to opposite area, where the lack of UVR should exist in spring month. These factors add the uncertainties to the information gaps in the status of Antarctic krill resources existed due to the insufficient recent scientific data. To study the possible influence upon ecosystem the available data of phytoplankton distribution in South Ocean in 1997-2007 and the fine-scale catch and effort data (C1 data) from vessels fishing for krill in the CAMLR Convention Area in 1974-2007 is started to analyze.

Assessing the impacts of fishing on Vulnerable Marine Ecosystems (VMEs) in the Southern Ocean is hampered by the paucity of information on the resistance and resilience of these ecosystems to disturbance. Both resistance and resilience of individual VME-forming taxa are related to their life-history characteristics. A global database of life-history characteristics, including growth rate, age, maximum size and reproductive parameters, was established for benthic, habitat-forming taxa and associated physical and chemical variables, including depth, temperature, oxygen concentration, salinity and nutrients. Meta-analyses revealed that there were strong, consistent relationships among life-history characteristics and with physical and chemical variables. Where records for the Southern Ocean exist, they fall within general global patterns. To demonstrate how these relationships might be used to assess vulnerability to fishing data are presented for the phylum Cnidaria, an important group of habitat-forming organisms that are known to occur in the Southern Ocean. These data show significant relationships between growth, age with temperature and/or depth suggesting that these taxa will show low resilience to disturbance in the Southern Ocean. Furthermore, many deep or cold-water species brood their offspring, a trait correlated with low dispersal capability. Recovery trajectories in the orders of many decades or centuries are predicted.

Climate change in the Antarctic is having major impacts on physical and biological systems. For the Adélie penguin, which breeds around Antarctica, different populations have been subject to different environmental conditions over space and time. To assess the ability of the Adélie penguin to cope with recent rapid climate change, survivorship, fecundity, age at first breeding, and breeding success from long-term monitoring sites across the latitudinal range of Adélie habitats were compared. Inflexible life history traits associated with fecundity, but spatial variability in survival rates and the age of first breeding show that Adélie populations do respond, in situ, to local climate change. However, the responses have been insufficient to maintain positive population growth rates in the Antarctic Peninsula region. Here, the rapid rate of climate change appears to have exhausted the ability of Adélie penguins to persist in natal habitats.

Using data collected by U.S. Antarctic Marine Living Resources (AMLR) Program during January surveys 2003 to 2007, we examine the spatial relationships between baleen whale distributions and Antarctic krill (Euphausia superba) abundance and demography near the South Shetland Islands (Antarctic Peninsula) and test whether whales exhibit interspecific differences in their exploitation of krill resources. Whale distributions were based on visual surveys and krill distribution, abundance and demographic characteristics were derived from net haul data. Approximately 25,000 km² and 500 net hauls were sampled over five years resulting in the most comprehensive linked whale-krill study in the SW Atlantic Ocean. We used a combination of spatial regression techniques, incorporating spatial autocorrelation, to model the overlap between three species of baleen whales and their krill prey. Whales exhibited affinities for particular krill hotspots characterized by different length-maturity stages Humpback whales (Megaptera novaengliae) show strong spatial associations with small juvenile krill in Bransfield Strait, whereas fin whales (Balaenoptera physalus) are associated with large mature krill located offshore within the Antarctic Circumpolar Current. The spatial segregation of krill length-maturity stages provides an important link to understanding the spatial structure of whale feeding grounds. Implications for the conservation of whales and management of krill fisheries are discussed.

High densities of vulnerable marine ecosystem (VME) indicator taxa were encountered in 17 areas off the northern Antarctic Peninsula and 11 areas off the South Orkney Islands (CCAMLR Subareas 48.1 and 48.2). These areas, which have been proposed for inclusion in the CCAMLR VME registry, were detected during the 2006 and 2009 U.S. Antarctic Marine Living Resources Program surveys. The VMEs were detected in most cases utilizing occurrence and abundance of VME indicator taxa in research bottom trawl samples, as well as by way of in situ observations with an underwater photographic/video imaging system. Using standardized densities of VME taxa from bottom trawl samples, we propose one possible trigger level that could be used to provide a basis for notification of a VME, based on CCAMLR Scientific Committee deliberations and current CCAMLR Conservation Measures. We further present a breakdown of ‘heavy’ vs. ‘light’ VME indicator taxa with consequences on the proposed trigger, as well as the rationale for potential additional VMEs in Subarea 48.2 (not notified), based on rarity of taxa and/or uniqueness of community.

In 2008, the Ukraine submitted a paper to the Scientific Committee highlighting the magnitude of the scientific uncertainties and data gaps affecting the subdivision of precautionary catch limits among SSMUs in Area 48 (CCAMLR- XXVII/43). The Ukraine suggested that a research plan was necessary for CCAMLR to fill those gaps, together with developing in future a funding mechanism to support the data obtaining process financially. The discussion of that issue at 2009 WG-EMM meeting will be useful in a course of the consideration a decision on a Stage 1 allocation. In addition, this meeting provides a good opportunity to discuss the possibility for the working group to come up with a research and monitoring plan for krill in Area 48. Due to the high level of risk associated with maintaining the current fishing pattern, in the event that WG-EMM is not able to deliver a recommendation on Stage 1 allocation, the working group would consider interim protective measures to protect krill predators from the impacts of fishing. In order to adequately incorporate current uncertainties in regards to krill, krill catches, predators, and environmental, the level of combined uncertainties could be quantified through a simple index - “uncertainty coefficient”.