CCAMLR

The Ross Sea, Antarctica, is amongst the least human-impacted marine environments, and the site of the world’s largest Marine Protected Area, the Ross Sea region Marine Protected Area. We present research on two components of the Ross Sea benthic fauna: mega-epifauna, and macro-infauna, sampled using video and multicore, respectively, on the continental shelf and in previously unsampled habitats on the northern continental slope and abyssal plain. We describe physical habitat characteristics and community composition, in terms of faunal diversity, abundance, and functional traits, and compare similarities within and between habitats. We also examine relationships between faunal distributions and ice cover and productivity, using summaries of satellite-derived data over the decade prior to our sampling. Clear differences in seafloor characteristics and communities were noted between environments. Seafloor substrates were more diverse on the Slope and Abyss, while taxa were generally more diverse on the Shelf. Mega-epifauna were predominantly suspension feeders across the Shelf and Slope, with deposit feeder-grazers found in higher or equal abundances in the Abyss. In contrast, suspension feeders were the least common macro-infaunal feeding type on the Shelf and Slope. Concordance between the mega-epifauna and macro-infauna data suggests that non-destructive video sampling of mega-epifauna can be used to indicate likely composition of macro-infauna, at larger spatial scales, at least. Primary productivity, seabed organic flux, and sea ice concentrations, and their variability over time, were important structuring factors for both community types. This illustrates the importance of better understanding bentho-pelagic coupling and incorporating this in biogeographic and process-distribution models, to enable meaningful predictions of how these ecosystems may be impacted by projected environmental changes. This study has enhanced our understanding of the distributions and functions of seabed habitats and fauna inside and outside the Ross Sea MPA boundaries, expanding the baseline dataset against which the success of the MPA, as well as variability and change in benthic communities can be evaluated longer term.

We provide a summary of the New Zealand research voyage to the Ross Sea region in 2021. The Ross Sea Life in a Changing Climate (ReLiCC) 2021 voyage on RV Tangaroa, TAN2101, was the first of two research voyages to the Ross Sea region funded by the New Zealand Ministry of Business, Innovation, and Employment (MBIE) for the 2021 and 2023 austral summer seasons. The over-arching purpose of this multi-disciplinary research voyage was to increase knowledge about key environmental and biological processes in the Ross Sea region of Antarctica and the Southern Ocean, and thereby improve understanding of ecosystem function and likely responses to future change. The focus was on providing baseline information about the Ross Sea region Marine Protected Area (MPA) to allow scientific evaluation of its effectiveness. There were nine voyage objectives: 1) microbial plankton communities; 2) biogeochemistry; 3) coastal marine processes; 4) oceanography; 5) underway mapping; 6) mesopelagic fish; 7) zooplankton; 8) cetaceans; and 9) Southern Ocean safety systems evaluation. Weather and sea conditions were generally favourable during the voyage, and most of the work planned across the nine research objectives was completed. In addition to the nine core research proposals, the voyage also deployed surface-drifting weather buoys as part of the international Global Drifter Program, and several wave-monitoring drifters.

Sea ice algae in the Southern Ocean have strong ecological and biogeochemical significance, providing a lipid rich food-resource to keystone species such as Antarctic krill. Despite their ecological importance, estimating seasonal or interannual changes in ice algal production at the Antarctic circumpolar scale is not presently possible. We show that the product of ice concentration and irradiance penetrating into sea ice (E_ice) explains 69% of the variability in ice algal production at the sector and seasonal scale estimated from two respected sea ice algae models. After allowing for a greater quantum yield of sea ice algae in summer than in other seasons we estimated a simple light-based index of potential ice algal production (P_ice) and this explained 91% of the variability in modelled ice algal production. Our results suggest that between 1987 and 2017, ice algal production has generally increased with the largest increases seen off East Antarctica, the Weddell Sea, and the western Ross Sea.

Within the framework of the Marine Ecosystem Assessment for the Southern Ocean (MEASO), Pinkerton et al. (2021) brings together analyses of recent trends in phytoplankton biomass, primary production and irradiance at the base of the mixed layer in the Southern Ocean and summarises future projections. Satellite observations suggest that phytoplankton biomass in the mixed-layer has increased over the last 20 years in most (but not all) parts of the Southern Ocean, whereas primary production at the base of the mixed-layer has likely decreased over the same period. Different satellite models of primary production (Vertically Generalised versus Carbon Based Production Models) give different patterns and directions of recent change in net primary production (NPP) as they index different components of productivity. At present, the satellite record is not long enough to distinguish between trends and climate-related cycles in primary production. Over the next 100 years, Earth system models project increasing NPP in the water column in the MEASO northern and Antarctic zones but decreases in the Subantarctic zone. Low confidence in these projections arises from: (1) the difficulty in mapping supply mechanisms for key nutrients (silicate, iron); and (2) understanding the effects of multiple stressors (including irradiance, nutrients, temperature, pCO2, pH, grazing) on different species of Antarctic phytoplankton. Notwithstanding these uncertainties, there are likely to be changes to the seasonal patterns of production and the microbial community present over the next 50–100 years and these changes will have ecological consequences across Southern Ocean food-webs, especially on key species such as Antarctic krill and silverfish.

In 2016 the Commission adopted Conservation Measure (CM) 91-05, establishing the Ross Sea region Marine Protected Area. This paper updates the research and monitoring activities conducted by New Zealand relevant to the Ross Sea region Marine Protected Area, as encouraged by CM 91-05 paragraph 16(i)–(ii). Annex B of this Conservation Measure specifies the RSrMPA specific objectives and the Management Plan. In addition, Annex C specifies the Priority Elements for Scientific Research and Monitoring, including research and monitoring priorities and research and monitoring questions that should be addressed. We also recall the objectives of the RSrMPA and the research questions for research and monitoring for the RSrMPA. In 2016 the Commission adopted Conservation Measure (CM) 91-05, establishing the Ross Sea region Marine Protected Area. This paper updates the research and monitoring activities conducted by New Zealand relevant to the Ross Sea region Marine Protected Area, as encouraged by CM 91-05 paragraph 16(i)–(ii). Annex B of this Conservation Measure specifies the RSrMPA specific objectives and the Management Plan. In addition, Annex C specifies the Priority Elements for Scientific Research and Monitoring, including research and monitoring priorities and research and monitoring questions that should be addressed. We also recall the objectives of the RSrMPA and the research questions for research and monitoring for the RSrMPA.

A key aim in managing the harvest of Antarctic krill is to ensure the long-term sustainability of the fishery and the marine ecosystem, including krill-dependent predators such as seals, penguins and whales. If predators are to be used as indicators in the management of marine ecosystems (e.g., CCAMLR Ecosystem Monitoring Program; CEMP), the functional responses between predators and prey (i.e., the relationships between predators foraging rate and prey abundance) is a critical. Current CEMP predator response variables, however, show variable relationships with estimates of krill abundance and those associated with monitoring foraging behaviour makes poor use of modern telemetry technology. Our primary objective is to develop monitoring indices that can quantify and characterize functional responses of penguins to changes in their prey field, as a precursor to developing additional CEMP monitoring parameters that will improve ecosystem-based Feedback Management (FBM). Here we present exploratory analyses of chinstrap penguins Pygoscelis antarctica foraging behaviour at two sites in the Bransfield Strait (Deception Island, Kopaitic Island) as a first step towards developing alternate monitoring indices of the functional relationships between predator foraging behaviour and prey abundance.

The Russian  krill research in Subarea 48.1 and 48.2 under CM 24-01 paragraph 2 were carried out by  RV “Atlantida”  in the period January-March 2020  including acoustic surveys, accompanied by a wide range of ecosystem studies on the biology of  krill and its habitat (hydrometeorological, oceanological and hydrochemical data) and  bio-productivity indices  (chlorophyll, primary production, phyto-, zoo- and ichthyoplankton).  This krill research was carried out in accordance with the CCAMLR Survey 2000 formats and CCAMLR recommendations.  The study area in Subarea 48.1 and 48.2 was about 480 thousand km².  Survey provides up-to-date information on krill biomass distribution and environments at varies spatial scales.  The total krill biomass estimated at the survey area was 39, 29 mln.t , CV=9,29%.  Statistical characteristics of krill biomass by stratum are shown. An analysis of oceanological conditions in January-March 2020 confirmed the main patterns of krill  distribution depending on the structure and dynamics of waters. Krill concentrations were observed in the zone of interaction between the waters of high latitude modification (Weddell Sea waters) and the waters of the southern periphery of the ACC  as well as in the marginal (shadow) zones, with eddies and gyres characteristic of shelf and slope areas. The krill length compositions are characterized by spatial heterogeneity, which is demonstrated by its distribution across strata and in different modifications of water masses (ACC  and the Weddell Circulation ).   The latter primarily relates to the content of the recruitment share. In the long term, the distribution patterns of krill and their habitat environment in Subarea 48.1 and 48.2 practically did not undergo significant changes

This paper discussed the krill flux indices through the Antarctic Peninsula based on the results complex survey provided by RV Atlantida in 2020 including   repeated complex acoustic surveys in the Brnsfield Strait and repeated transect across Elephant Island.  Geostrophical water masses circulations, spatial distribution of krill density, water flow intensity (m³/s) and krill biomass (g/m³) transported by water flow , variability of krill length compositions are shown.  There was no krill fishing in the Bransfil Strait during the research surveys as well as between these surveys. The latter provided favorable conditions for understanding the effect of krill flux on krill  distribution and biomass in context of krill fishery management.

The length distribution and biological indicators (weight, sex, maturity phases and nutrition indicators) of Antarctic krill obtained  during the Russian complex survey on the RV "Atlantida" in January-March 2020 are shown. Analysis is based on 179 standard  double oblique tows with research trawl.  The length distribution and biological indicators were analyzed by strata including the South Shetland Islands stratum (SSI), the Bransfield Strait stratum (BS), the Elephant Island and the Joinvile Island strata (EI), the Scotia Sea stratum (SS).   The catch basis was formed by mature and post-spawning krill individuals, females of stage IIIA and IIIE, males of stage-IIIB.

This report summarizes the spatial layers developed to date to support the development of the Weddell Sea Marine Protected Area Phase 2.  We link these spatial layers to the conservation objectives complementary to the Weddell Sea Marine Protected Area Phase 1 and preliminary specific conservation objectives for the Weddell Sea Marine Protected Area Phase 2. We include a summary of further considerations from expert discussions at and since the WSMPA Phase 2 International Scientific Workshop (digital) 10-12 May 2021. A summary report of this workshop is provided as supplementary material.