CCAMLR

A Marine Ecosystem Assessment for the Southern Ocean (MEASO) is a quantitative assessment of the status and trends of habitats, species and food webs in different regions.  It aims to provide a common foundation for all end-users on which science can be developed, and policies and decisions can be made.  It is intended to enable managers to achieve consensus in adapting their management strategies to ecosystem change, in order to continue to achieve their objectives for ecosystems. ​ This paper briefly describes MEASO activities during 2018.  

This paper reports on available CEMP data and details of use as a guide for CEMP-related analyses, including an update on CEMP metadata available on the CCAMLR GIS and as hosted on the NASA Global Change Master Directory (GCMD). CEMP data submissions for the 2017/18 season are detailed by site and species, and a brief overview on general trends from the past three seasons by Subarea or Division has been included.

The Combined Standardised Index (CSI) analysis has been updated from 2017 for Area 48 in order to compare patterns of inter-annual variability. Spatial analysis shows evidence of concordance of response to changes in the ecosystem between sites by Subarea, suggesting CEMP data are tracking similar processes. Further analysis to understand emerging trends and specific indices driving these patterns are required.

• The Antarctic region is characterized by complex interaction of natural climate variability and anthropogenic climate change that produce high levels of variability in both physical and biological systems, including impacts on key fishery taxa such as Antarctic krill.

• The impact of anthropogenic climate change in the short-term could be expected to be related to changes in sea ice and physical access to fishing grounds, whereas longer-term implications are likely to include changes in ecosystem productivity affecting target stocks.

• There are no resident human populations or fishery-dependent livelihoods in the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) Area, therefore climate change will have limited direct implications for regional food security. However, as an “under-exploited” fishery, there is potential for krill to play a role in global food security in the longer term.

•The institutional and management approach taken by CCAMLR, including the ecosystem-based approach, the establishment of large marine protected areas, and scientific monitoring programmes, provides measures of resilience to climate change.

The abundance of the Antarctic krill (Euphausia superba) has been declining in the western Antarctic Peninsula (WAP), probably as a consequence of the effects of the considerable increase in the sea surface temperature observed in the region. Thus, the performance (reproduction and survival) of the krill consumers may be compromised. In the present study, we investigated the reproductive success of humpback whales (Megaptera novaeangliae) from Breeding Stock G in relation to krill density.  The result we found suggests that the warming off the WAP and the expected future increase in the frequency of extreme El Niño events may compromise humpback whale’s rate of recovery in the Southern Hemisphere if such changes negatively affect the production of krill. Therefore, it is recommended that management strategies for krill fisheries consider the effect of climate on the whole Antarctic ecosystem and the potential effect of krill removal on the population recovery of whales.

Climate change will alter the structure and functioning of Southern Ocean ecosystems and affect the ecosystem services they provide. The impacts of climate change will require development of conservation and management strategies that anticipate and adapt to potential changes in krill population dynamics. A recent collaborative workshop between the Integrating Climate and Ecosystem Dynamics in the Southern Ocean (ICED) programme and CCAMLR brought together a range of ecologists, physical and ecological modellers and fisheries scientists to consider the development of projections of the impacts of climate change upon krill in Area 48. Here we present the preliminary findings of this workshop: ‘Developing projections of the future state of Southern Ocean ecosystems: Incorporating uncertainties associated with climate variability and change in CCAMLR’s decision making’ held at CCAMLR Headquarters, 5-7 April 2018. The Workshop highlighted the high level of natural spatial and temporal variability of the ecosystem in Area 48. The current suite of scenarios of future changes in physical, chemical and ecological drivers across the region are highly uncertain and global climate models do not resolve ocean and sea-ice processes that are important within Area 48. As a result of that uncertainty, signals of projected changes in SST and sea-ice are not distinguishable from model variability before ~2050. Surface waters are expected to warm and sea ice concentrations reduce, but the position of the polar front is not expected to change during this century. The changes expected by the end of the century are likely to cause distribution shifts and reconfiguration of food webs, with both positive and negative effects. The Workshop highlighted our poor understanding of krill recruitment processes, the key driver of variability in krill populations across the region, and particularly their links to sea ice. It also emphasized the need for a systematic development of krill population models and high spatial resolution ecosystem models. The Workshop noted the importance of developing a joint approach between ICED and CCAMLR to improve scenarios and ecosystem models and develop quantified model projections of ecosystem change in support of decision making for conservation and management. A final version of the report and agreed statements will be submitted as a Working Paper for consideration at SC-CAMLR-XXXVII.

The previously presented document at the 2018 ASAM WG meeting (ASAM-18-07) described a design and plans for a synoptic krill acoustic survey in CCAMLR area 48 in 2019. The survey involves the collaborative efforts of Norway, Association of Responsible Krill fishing companies (ARK: companies from Norway, Korea, China and Chile), the United Kingdom, Ukraine, Korea and China, all of whom have confirmed a commitment of survey ship time. With these commitments it is feasible to implement all transects occupied during the 2000 survey. This document is a draft survey manual, produced at the recommendation of the 2018 ASAM meeting, and describes acoustic procedures, acoustic reporting - analysis procedures and contingency plans.

The estimates of fur seal consumption of krill in subareas 48.1 to 48.3 which have been used in ecosystem modelling and CCAMLR’s risk assessment approach, are based on the distribution of fur seal breeding populations. Fur seal breeding colonies south of 60^o have remained relatively small and their biomass is orders of magnitude less than those of penguins. As a result the estimates of fur seal consumption outside of the South Georgia region, where ~95% of the population breeds, are relatively insignificant. However evidence from the growing body of tracking data has revealed the importance of the South Orkneys and Peninsula regions to male fur seals during their post mating dispersal from breeding sites on South Georgia. Using a combination of published and BAS data we highlight the potential importance of this connectivity. Our estimates suggest that the influx of fur seal males from South Georgia has a significant impact on the marine environment around the South Orkney Islands with a potential total krill consumption of approximately 86,500 tonnes. This is very likely an underestimate as it is based on a census of the fur seal population at South Georgia from 1991 which represented a year of poor environmental conditions. This population has also undoubtedly grown since this count. Our estimates also do not account for the need of male fur seals to recover condition during this time after fasting during the mating season and a number of important data gaps exist. We recommend further detailed analysis is prioritised in order to provide more robust estimates of the fur seal impact on this region that can be used to inform management, including through the risk assessment framework.

Age information for commercial fish species is crucial to fishery management. Age information for Antarctic krill (Euphausia superba) will be important for stock assessment modeling and future feedback management of krill fisheries. Samples stored in 70% ethanol provide an opportunity to detect the growth bands of eyestalk sections. Moreover, information derived from samples preserved in formalin will have a greater impact on the feedback management process because this preservation method was more common in previous decades. Out of 162 Antarctic krill individuals preserved in 5% formalin, the growth bands from eyestalk sections of 134 samples were readable. The relationship between the total length and the growth bands in the eyestalk was analyzed. Three main parameters, including exact percent agreement (EPA), coefficient of variation (CV), and average percentage error (APE), were used to evaluate the precision of the growth bands.Results show decreased CV and APE values and an increase in the EPA value with the accumulation of reading runs.  The estimated VBFGs were expressed as L_t=60.50*(1-e^{-0.50*(t-0.45)}) for males and L_t=69.59*(1-e^{-0.25*(t+0.58)}) for females, respectively (note: those infromation were not including published paper). This method is direct and uses a grinding and polishing technique before reading, contrary to Krafft et al. (2016) and Kilada et al. (2017). Combined with published studies, specimens collected from autumn to winter in this study can provide a better understanding of Antarctic krill growth. This study presents important information for age determination, particularly for specimens preserved in formalin, and will benefit the stock assessment and acoustic estimation of this species in the future. Further studies are required to validate the correlation between growth bands and age. Additionally, more samples from different seasons and regions are also needed to fully understand the growth dynamics of this species.

The aim of the ECOgaps is to improve the knowledgebase on physical conditions and biota east of the 0 meridian in the MPA planning Domain 4. Focusing on the Astrid ridge, the continental shelf off of Dronning Maud Land, and the Maud rise, multidisciplinary investigations will be conducted in 2019 by the RV Kronprins Haakon. In this working document, the cruise being planned is outlined. Aims and activities of the six scientific work-packages of the project are described.

The RAPID-KRILL project is funded by the Antarctic Wildlife Research Fund to develop at-sea automated processing of acoustic data on fishing and research vessels. An update on the project progress is presented here, including an overview of the data processing methods.