The most common and widespread salp in the Southern Ocean is Salpa thompsoni. It is characterized by a circumpolar distribution and its appearance is clearly associated with the occurrence of the Antarctic Circumpolar Current (ACC). This area of the Southern Ocean is characterized by a relatively low productivity and high water temperature. In recent years the expansion of distribution range of this invertebrate species has been observed. This process may be a result of the ACC southward movement, which is caused by ocean warming and variability in sea ice extent. The presented time series is based on samples collected between 1975 and 2001 in the region of Western Antarctic Peninsula. The results of laboratory analyses, coupled with environmental data, obtained both during sampling and from satellite data, allowed to prove that the distribution of salps was significantly correlated with water temperature and presence of sea-ice, while their abundance resulted from salinity and temperature. The results of our study suggest that with climatic changes, such as temperature increase and reduction of sea-ice cover, the distribution range and abundance of Salpa thompsoni is likely to increase in the Western Antarctic.

Feedback Management (FBM) requires adequate data that can be collected with a minimum of extra effort. Traditional survey practice requires a pre determined survey design that support statistical handling of the collected data into stock abundance information. Godø et al. (2015) (WG-EMM-15/13) show the inherent variability of catch and acoustic data collected during fishing operation. At the same time the data might inform about patterns in the ecosystem of importance to FBM. Similarly, Niklitschek and Skaret (2015) (EMM-16 doc) utilize spatial statistics to show that fisheries acoustic data recorded during regular fishing operations give consistent information about spatial and temporal distribution and abundance of krill in the South Orkney Islands. However, due to the lack of survey design there is an unknown impact/uncertainty of the effect of using data collected during aimed trawling at high krill concentrations.  It is suggested that combining their approach with a conventional design might inform about some of this uncertainties. In this paper we discuss how the information of these two papers can be used in an operational FBM.

There is a substantial harvestfor Antarctic krill in the Southern Ocean, butlittle regular scientific monitoring of the resource. Recently, however, the Commission for the Conservation of Marine Living Resources (CCAMLR) has initialised a process to make use of acoustic data from commercial fisheries to increase the amount of relevant information available for making management decisions. We here provide an example where 34 days of acoustic data, collected during commercial krill fishing operations on the vessel ‘Saga Sea’ were processed to produce probability of presence, conditional density and relative abundance estimates on monthly, weekly and daily basis. Data were analyzed using a maximum likelihood time-series and geostatistical approaches, selected to account for the lack of sampling design, and likely correlation in space and time. The applied method showed low sensitivity of monthly estimates to different repeated measure criteria and location sub-settings. Most weekly estimates, but the last one, were also consistent with the full data (monthly) estimate. Highly variable and lower estimates were obtained, however, from daily data sets. Although our results suggest the method had provided an adequate treatment for time and space correlation, we were not able to evaluate potential bias due to preferential sampling of high density krill aggregations and/or limited area coverage within short time periods. The results suggest that this method, combined with some additional design based coverage by the fishing vessels, can be useful to obtain quantitative evaluations of krill density and distribution for management purposes.

Weather extremes are one important element of ongoing climate change, but their impacts are poorly understood because they are, by definition, rare events. If the frequency and severity of extreme weather events increase, there is an urgent need to understand and predict the ecological consequences of such events. In this study, we aimed to quantify the effects of snow storms on nest survival in Antarctic petrels and assess whether snow storms are an important driver of annual breeding success and population growth rate. We used detailed data on daily individual nest survival in a year with frequent and heavy snow storms, and long term data on petrel productivity (i.e., number of chicks pro- duced) at the colony level. Our results indicated that snow storms are an important determinant of nest survival and overall productivity. Snow storm events explained 30% of the daily nest survival within the 2011/2012 season and nearly 30% of the interannual variation in colony productivity in period 1985–2014. Snow storms are a key driver of Antarctic petrel breeding success, and potentially population dynamics. We also found state-dependent effects of snow storms and chicks in poor condition were more likely to die during a snow storm than chicks in good condition. This stresses the importance of con- sidering interactions between individual heterogeneity and extreme weather events to understand both individual and population responses to climate change. 

Polar Regions are experiencing environmental changes at unprecedented rates. ese changes can spread throughout entire food webs from lower trophic levels to apex predators. As many top predators forage over large areas, these indirect e ects may be associated with large-scale patterns of climate variability. Using global climate indices that are known to impact the Southern Ocean ecosystem (the El Niño Southern Oscillation and Antarctic Oscillation Indices) we assessed their e cacy to predict variation in the demographic parameters of Antarctic seabirds. First, we used a long-term dataset on adult survival (estimated from capture–mark–recapture data) and reproduction of Antarctic petrel alassoica antarctica, from the largest known breeding colony (Svarthamaren, Dronning Maud Land) and examined whether large-scale oceanographic uctuations impact survival and reproduction. Second, we conducted an exhaustive literature review to determine whether the e ects of large-scale environmental variability on Antarctic seabirds have a coherent ngerprint across the Antarctic continent and nearby islands. We found that most of the variation in both reproductive success, timing of hatching, and survival of Antarctic petrels can be accurately modeled using the two modes of large-scale climate variability in Antarctica. e literature review, combined with the results from our eld study, suggests that while the anticipated trends in the global patterns of climatic variability will generally have detrimental e ects on populations of top predators in the Southwest Atlantic, these conclusions cannot be extrapolated to all seabird populations in Antarctica without additional data. 

Commercial fisheries may impact marine ecosystems and affect populations of predators like seabirds. In the Southern Ocean, there is an extensive fishery for Antarctic krill Euphausia superba that is projected to increase further. Comparing distribution and prey selection of fishing operations versus predators is needed to predict fishery-related impacts on krill-dependent predators. In this context, it is important to consider not only predators breeding near the fishing grounds but also the ones breeding far away and that disperse during the non- overlap between the distribution of the Antarctic krill fisheries and the distribution of a krill dependent seabird, the Antarctic petrel Thalassoica antarctica, during both the breeding and non-breeding season. We tracked birds from the world biggest Antarctic petrel colony (Svarthamaren, Dronning Maud Land), located >1000 km from the main fishing areas, during three consecutive seasons. The overall spatial overlap between krill fisheries and Antarctic petrels was limited but varied greatly among and within years, and was high in some periods during the non-breeding season. In a second step, we described the length frequency distribution of Antarctic krill consumed by Antarctic petrels, and compared this with results from fisheries, as well as from diet studies in other krill predators. Krill taken by Antarctic petrels did not differ in size from that taken by trawls or from krill taken by most Antarctic krill predators. Selectivity for specific Antarctic krill stages seems generally low in Antarctic predators. Overall, our results show that competition between Antarctic petrels and krill fisheries is currently likely negligible. However, if krill fisheries are to increase in the future, competition with the Antarctic petrel may occur, even with birds breeding thousands of kilometers away. 

Adaptive feedback management is a core component of the ecosystem based management approach that is being implemented by the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) and Antarctic Treaty System (ATS). The Mapping Application for Penguin Populations and Projected Dynamics (MAPPPD) is a web-based, open access, decision support tool that would greatly assist meeting the management objectives as set forth by CCAMLR and other components of the ATS (i.e., Consultative Meetings and the ATS Committee on Environmental Protection). The database underlying MAPPPD includes all available (published and unpublished) data on the four Sphenisciforme penguins (Emperor; Aptenodytes forsteri; gentoo; Pygoscelis papua; Chinstrap; P. antarcticus; and Adélie penguins; P. adelieae) for the region south of 60° S. A Bayesian population model integrates the available data to develop estimates of abundance for each site and for each year since 1979; estimates are easily aggregated across multiple sites to obtain abundance estimates over any user-defined area of interest. A front-end web interface located at www.penguinmap.com provides easy access to the data, with a web based map that allows users to select individual or groups of site(s) using polygons or text searches. Once selected, population data from the model (including future forecasts) are displayed and made available for download. Users can also generate a PDF report that summarizes the data for the sites selected from the application. MAPPPD provides free and ready access to the most recent count and modeled data, and can act as a facilitator for data transfer between Antarctic stakeholders to help inform management decisions for the continent.

Petermann Island (65°10'S, 64°10'W), one of the Antarctic Peninsula’s most frequently visited locations, is at the epicenter of a rapid shift in which an Adélie penguin dominated fauna is becoming gentoo penguin dominated. Over the course of five seasons, the breeding productivity of Adélie and gentoo penguins breeding at Petermann Island were monitored to identify drivers of this rapid community change. The impact of tourist visitation on breeding success was also investigated. Consistent with larger trends in this region, the Adélie penguin population decreased by 29% and the gentoo penguin population increased by 27% between the 2003/2004 and 2007/2008 seasons. Reproductive success among Adélie penguins ranged from 1.09 to 1.32 crèched chicks/nest, which was higher than or comparable to other sites and is an unlikely explanation for the precipitous decline of Adélie penguins at Petermann Island. Whereas gentoo penguin reproductive success was lowest in colonies frequently visited by tourists, Adélie penguin colonies frequently visited by tourists had higher reproductive success than those visited only occasionally. These results are placed in the context of other studies on reproductive success and the impact of tourist visitation on breeding colonies of Adélie and gentoo penguins.

Changes in the Antarctic ecosystem have been triggered by anthropogenic and natural factors. This paper reviews the scientific information of whales that could be indicative of changes in the East Antarctica ecosystem in the context of two hypotheses, the ‘krill surplus’ hypothesis in the middle of the past century and the recovery of krill-eater large whales since the 1980’s. There was an interest to investigate the effects of those events on other krill predators such as the Antarctic minke whale, which had not been exploited on a large scale. A review of the scientific information in East Antarctica (70°E-170°W) showed that the increased krill availability in the middle of the past century could have been translated into better nutritional conditions for some krill predators like the Antarctic minke whale, resulting in a decreasing trend in the age at sexual maturity of this species between approximately 1940 and 1970. A low age at sexual maturity favored an increase in the recruitment rate and total population size in a similar period. The evidence available since the 1980’s showed a sharp increase in the abundance of some species in East Antarctica such as the humpback and fin whales. The evidences also showed that the nutritional conditions of Antarctic minke whales have deteriorated as revealed by a decrease in energy storage and stomach content weight since the 1980’s. This observation is consistent with the stable trend of age at sexual maturity and recruitment after 1970’s. The stable trend in recruitment is consistent with the total abundance of Antarctic minke whale estimated by sighting surveys, which has been broadly stable since the 1980’s. The observations above suggest availability of krill for Antarctic minke whales could have decreased in recent years. Decrease in availability of krill for this species could result from competition with other recovering krill-eater large whale species, e.g. the reversal of Law’s ‘krill surplus hypothesis’. Environmental factors alone are unlikely to explain the observed changes in demographic parameters in Antarctic minke whales. An implication of this is that in East Antarctica, competition for space and food could better explain the pattern of changes in biological and demographic parameters observed among sea-based krill predators. However to further investigate the plausibility of this hypothesis it will be necessary to obtain information on krill biomass trends in the research area. There is some partial information based on past dedicated krill surveys but the information is scattered and needs to be combined with new surveys in a comprehensive and consistent way so that a time series can be obtained.

Due to uncertainties in Antarctic krill stock, which do not allow scientists to develop comprehensive system of Feedback management of krill fishery and to provide work on forecast of the ecosystem changes, Ukraine proposes to change the Conservation Measure 51-06(2014) making the scientific observation system in the krill fishery mandatory.