CCAMLR

The influence of the climate change on krill based Southern Ocean ecosystem is studied intensively last decade. To study the possible connections between Antarctic Peninsula regional climate warming and ecosystem changes the data of Antarctic krill density (KRILLBASE data) and of surface air temperature (READER data) were used. Decadal variability of winter temperature on the regional scale was analyzed. We apply Fourier and wavelet analysis to the averaged temperature anomaly time series and note the oscillations with 3-8 year periods and a decadal oscillation with a period of about 16 years. Preliminary analysis of Antarctic krill density variations shows about 8-year variability as well. Correlation coefficient between krill density data and temperature anomalies is small (less 0.2) however is increased significantly to 0.4 when applying 1-year data shift (krill density after anomalies occurrence). The 3-8 year periods possibly related to the ENSO variations and connected to sea ice change.

Species composition and abundance of by-catch fish were analyzed using the fish by-catch samples collected by scientific observers onboard Japanese commercial krill fishing vessels in the north of South Georgia during the austral winter from 2002 to 2008. A total of 19 species belonging to 8 families were identified in the by-catch samples, among which the 3 species, Krefftichthys anderssoni, Lepidonotothen larseni and Champsocephalus gunnari, were recorded in every year from 2002 to 2008, and also the most abundant. Different life stages of K. anderssoni, Gymnoscopelus nicholsi, C. gunnari and L. larseni from larvae to adults were found, suggesting that these species may have their nursery ground around South Georgia. The length frequency distribution of C. gunnari varied with years and may indicate the increase in size in recent years. Electrona antarctica was not a major component of the recent mesopelagic ichthyofauna. In contrast, P. choriodon, which is known as a South temperate species, became to dominate the recent samples. Additionally, the size distribution of P. choriodon was unimodal, indicating that the individuals probably migrated from the population in northern warmer areas. Since the distribution patterns and biological peculiarity of fish are related to oceanographic conditions, the shifts in species and size composition may demonstrate oceanographic and climatic changes in the Antarctic Ocean. Long-term monitoring of ichthyofauna through the scientific observer program and close examination of the biological samples would provide important information on environmental fluctuations in the Antarctic Ocean.

To investigate spatio-temporal variability of krill body length and number of bycatch fish, observer data sets on Japanese krill fishery from 1995 to 2008 were analyzed by using a hierarchical Bayesian model. The model was composed of multistage cluster units (i.e., years, subarea, vessels, and haul) based on a state-space model, which can separate biological process error in the population dynamics from observation error caused by the fishery activity and individual observation. In both krill length and bycatch fish number, the parameters estimated by MCMC showed the variation among years, subareas, and vessels. The potent interaction effect between year and subarea suggests large spatiotemporal variability of krill population structure and a difficulty in predicting krill population dynamics. Variances of krill length and bycatch fish number by sampling stages were calculated by the multistage sampling formula with the variance terms derived from the Bayesian model. For both krill length and bycatch fish number, haul coverage ranging 0–50% showed marked effects on CV, although vessel coverage hardly changed CV. The results of this study suggest that scientific data collectionby commercial fishery is an important source of information for the management of krill resources and Antarctic ecosystem, while enlarging haul coverage > 50% have smaller effects in improving data accuracy and may not balance the rising cost of observer program.

At WG-EMM-09 the Working Group noted that the photographic method used in WG-EMM-09/38 could be incorporated as a modification of CEMP Standard Method A3 (penguin breeding population size). This paper reviews aspects of Methods A3a, A3b and related A9 (breeding chronology) in the most recent version of the CEMP Standard Methods that are relevant to this proposal, outlines some difficulties in the practical application of these Methods, and proposes some general modifications to the Methods to allow greater flexibility in the collection and interpretation of penguin breeding population counts.

Cameras and other optical instruments are increasingly being used as cheap, convenient and reliable tools for surveillance and monitoring. This paper describes (1) the kinds of observations and measurements relevant to CEMP that can be obtained from an automated camera system specifically developed for use in the extreme conditions of Antarctica, (2) a preliminary assessment of the utility of cameras for measuring Adélie penguin breeding success, and (3) how cameras are currently being used to expand the spatial extent of Adélie penguin monitoring, and to extend monitoring to additional land-based breeding species, in east Antarctica.

We made a survey plan to observe krill escapement, attached an underwater video camera on a trawl net of a Japanese commercial trawler, and started observation to collect video images of krill passage through the rope and netting parts of the trawl net. Preliminary examination of video images obtained via satellite-linked transmission indicated very low incidence of krill escapement from top panels near the net opening.

Japan is trying to use information obtained through the fishery effectively, and planning an acoustic survey using a commercial krill fishing vessel that enables annual data collection. This proposal focuses on monitoring yearly trend of krill distribution and fishing ground formation. The goal of this survey is to obtain scientific information by fishing vessel on a regular basis.

A recent gap analysis of knowledge of the breeding distribution of the Adélie penguin across the Australian Antarctic Territory in east Antarctica found that approximately half of the species’ potential breeding habitat had no evidence of ever being searched. With such incomplete knowledge of the current breeding distribution, it is not possible to reliably assess possible future change in breeding distribution due to broad-scale environmental change, or to reliably estimate the current size of breeding populations. This paper describes a comprehensive, large-scale survey of the current breeding distribution of Adélie penguins along 3000 km of the east Antarctic coastline. The survey found 44 unreported breeding sites, increasing the number of known breeding sites in the survey region by 42% from 104 to 148.

Phenological changes are touted to be an early indication of species response to environmental change and have been reported for a range of species around the globe. In Antarctica, there is a clear indication of phenological changes for the Adélie penguin (Pygoscelis adeliae) with contrasting trends in clutch initiation dates reported for populations on opposite sides of Antarctica. Such shifts in breeding phenology can be indicative of environmental change when cues for breeding initiation are tightly linked with environmental conditions or may reflect other underlying causes such as changes in a species food supply. Here we outline the underlying factors which can affect the timing of various phenophases of the breeding cycle and describe shifts in Adélie penguin breeding phenology reported at different locations around the Antarctic continent.

Understanding circumpolar penguin abundance is critical for developing realistic ecosystem models that might be used to inform the management of impacts due to climate change or fisheries. A review of historical Adélie penguin survey data in east Antarctica revealed Prydz Bay as a priority region for new survey work to improve population estimates. Prydz Bay is considered to have the largest breeding population of Adélie penguins in east Antarctica but the most recent abundance survey was conducted 30 years ago. To understand current levels of prey consumption in east Antarctica it is therefore critical to understand if population numbers in Prydz Bay have changed in the past three decades. Accordingly, an aerial photography survey was undertaken in 2009/10. The survey used sample counts to estimate abundance for two sub-regions, comparative air and ground counts to assess detectability of penguins from the air, and data obtained from cameras to adjust counts to a point in the breeding chronology consistent with CEMP Standard Method A3. Recent abundance estimates are approximately double those obtained in the early 1980s. The new abundance estimates will significantly improve estimates of prey consumption by Adélie penguins in this region.