Norway is in the process of extending its monitoring efforts in the area around South Orkneys by deploying acoustic moorings in a commercially exploited area. Data gathered from the moorings will be used to parametrise models, in order to gain better understanding of the interaction between ocean physics and behaviour in driving krill biomass variation in the area.
Abstract:
The Antarctic minke whale (Balaenoptera bonaerensis) is the most abundant baleen whale species in the Southern Ocean. Quantitative information on prey consumption of whales is useful to understand their feeding ecology and role in the Antarctic marine ecosystem. The purposes of this study were 1) to investigate the feeding habits of Antarctic minke whales based on information on prey species in stomach contents, and 2) to estimate the amount of prey consumed by whales, accounting for some uncertainties. The analysis is based on the data from whales taken by JARPA (Japanese Whale Research Program under Special Permit in the Antarctic: 1989/90-2004/05) and JARPAII (2005/06-2013/14) in the Indo-Pacific region of the Antarctic (35°E-145°W). Sampling of Antarctic minke whales was conducted in the austral summer seasons, mainly in the months from December to March. The Antarctic minke whales fed mostly on Antarctic krill (Euphausia superba) in offshore area, and on ice krill E. crystarollophias in coastal (shallow) area on the continental shelf such as the Ross Sea and Prydz Bay. Daily prey consumption by the whales in each reproductive status group was estimated using an energy-requirement approach. Based on the results obtained by three equations combined and Monte Carlo simulations, the daily prey consumptions per capita of Antarctic minke whales were 207.1kg and 353.3kg for immature and mature males; and 229.3kg and 397.0kg for immature and mature females, respectively. The CVs of the daily prey consumption consumed by whales per capita were in the range 0.35-0.39. Consumption was equivalent to 4.9-6.3 % of body weight. The total per capita prey consumptions during the feeding season were 24.8 and 42.4tons for immature and mature males, 27.5 and 47.6tons for immature and mature females, respectively. Total prey consumptions of krill by Antarctic minke whales during the feeding season (120days) were estimated at 1.5 and 4.6 million tons in Areas IV and V, respectively. It is expected that the output of this study will assist the understanding of the role of the Antarctic minke whale in the ecosystem and development of ecosystem models.
Abstract:
The composition of penguin diet is currently monitored through the A8 CEMP Chick Diet monitoring parameter. The current Standard Method involves stomach lavage to collect the stomach contents of adult birds and sorting the samples to identify prey composition and mass. At WG-EMM-12 it was noted that Australia had stopped collecting penguin diet samples and that alternative, less invasive, procedures were under consideration. Here we discuss results from recent work using the extraction of prey DNA from penguin faecal samples as an alternative, non-invasive procedure. We describe the technique, discuss recent results and outline current thoughts on its advantages and limitations. We also outline a validation study currently underway on samples collected at Signy Island, South Orkneys, to compare the prey DNA from faecal samples and stomach lavage techniques.
Abstract:
Estimating the consumption of prey by higher-order predators is a priority for WG-EMM as an element in CCAMLR’s ecosystem-based approach to management for the krill fishery in the Southern Ocean. Previous assessments of prey consumption for seabirds have focussed on breeders using data recorded at the breeding colonies. However, recent work suggests that the size of the non-breeder component of an Adélie penguin population can be substantial compared with the size of the breeder population. This paper describes the extension and parameterisation of a bio-energetics model developed to estimate prey consumption by breeding Adélie penguins to include estimates of prey consumption for the non-breeder component of an Adélie penguin population. Given an estimate of non-breeder abundance, this development allows consumption to be estimated for the total population.
Abstract:
We outline progress on current work aimed to improve estimates of flying seabird abundance, and ultimately krill consumption, from land-based breeding bird counts of five species (Antarctic petrel, Cape petrel, southern fulmar, snow petrel and Wilson’s storm petrel) in Divisions 58.4.1 and 58.4.2. We compiled information on the historical search effort in potential seabird breeding habitat in these Divisions and conclude that only 2-3% of potential flying seabird breeding habitat has been searched for breeding populations. We conclude that a compilation of historical population counts where searches have been made substantially under-estimates the true breeding populations across all habitat, and alternate approaches are required to realistically estimate seabird abundance, and from that consumption. This conclusion is supported by preliminary results from a broad-scale sample survey of snow petrels. This work is an important contribution to estimating krill consumption by predators in Divisions 58.4.1 and 58.4.2 as part of a risk assessment for these Divisions. It complements similar work on other predator groups in the region including pack-ice seals and Adelie penguins and will contribute to estimating total krill consumption by these predator groups.
Abstract:
We provide a brief update on the progress of our CEMP Special Fund project ‘Developing an image processing software tool for analysis of camera network monitoring data’. The project was initiated with support from the CEMP Fund in 2015/16. A software programmer has been engaged and is currently working within the Australian Antarctic Division’s Data Centre to refine the software and develop post-processing code according to specifications developed in consultation with the CCAMLR camera user community. We expect to complete a package of software and post-processing code by early 2018.
Abstract:
The distribution and abundance of krill aggregation inhabiting the Subarea 48.1, which includes the Elephant Island peripheries and the west and south of the South Shetland Island, were estimated using an acoustics survey. Acoustic data were collected with 38 and 120 kHz from April 13 to 24 in 2016 and 38 and 200 kHz from March 6 to 14 in 2017. Krill were collected by the commercial middle trawl fishing vessel. The data were processed and analyzed following CCAMLR standard protocols using swarm integration (SHAPES module within that software for swarm identification) based on data from a transect-based survey. The weighted krill density and biomass were estimated to be 0.20 g/m2 and 18 thousand tons (CV=33.8%) applying Sv difference 3.96-5.91 dB and 0.92 g/m2 and 83 thousand tonnes (CV=31.4%) applying Sv difference -3.0-13.8 dB in 2017, respectively. Krill density and biomass were significantly higher in 2016 than those in 2017.
Abstract:
This paper aims to bring to light specific issues which precluded support by Norway of the Weddell Sea MPA proposal tabled to CCAMLR in 2016 by the delegation of the European Union and its Member States. We present results from Marxan and other analyses conducted for the purpose of evaluating aspects of the Weddell Sea MPA planning process which were integral to the development of the proposal, focusing on the suitability of the Marxan analysis to inform MPA border delineation and the potential impact to fisheries. We pose questions and make recommendations regarding the technical and procedural decisions made during the Weddell Sea MPA planning process, and discuss these concerns in the context of the transparency of the process, the consistency with other CCAMLR MPA planning processes, and Norway’s commitment to ensuring that any area-based management it supports is founded on a consistent and rigorous scientific basis.
Abstract:
Breeding birds can increase their foraging efforts to feed chicks after hatching. We investigated how chinstrap penguins (Pygoscelis antarctica) differ foraging diving behaviors with breeding stages. During incubation and chick-rearing period, from December 2015 to January 2016 on King George Island, Antarctica, diving characteristics of breeding chinstrap penguin parents were recorded by deploying GPS and Time-Depth Recorder (TDR). Our results showed that chinstrap penguins have wider-range diving areas and longer foraging trips during incubation period while they dive in on-shore areas for a short trip hours during chick-rearing period. In addition, chinstrap penguins exhibited deeper dive depths during chick-rearing than during incubation. Our results suggest that chinstrap parents change their foraging area and dive depth between incubation and chick-rearing, possibly due to the increased need of chick-feeding and the temporal changes in prey availability between the two reproduction stages.
Abstract:
To develop a long-term ecological research program at a breeding site of Adélie penguins, located in the Northern Victoria Land Coast, the Korea Polar Research Institute (KOPRI) carried out a preliminary survey on the population size and foraging trips of penguins at Cape Hallett. All sub-colonies were mapped using a portable DGPS and the data were complemented by comparing them with aerial images using an unmanned aerial vehicle (UAV). The Cape Hallett colony was composed of approximately 700 sub-colonies occupied by 53,450 pairs of Adélie penguins in 2016. The foraging area of the Adélie penguins (Pygoscelis adelie) determined from our loggers was 218.8 ± 366.8 km2 (mean ± SD).