CCAMLR

In the report we describe the season activity in the Ukrainian Vernadsky Antarctic Station area on installation CEMP cameras in penguin colonies as part of the CEMP project run by USA, Argentina, Poland and Ukraine 'Establishing a CEMP Camera Network in Subarea 48.1'. In season 2015/2016 we installed nine cameras at penguine colonies at Petermann, Yalour and Galindez Islands to monitor pengiune nests for breeding success and chronology. Cameras have been installed in the middle of breeding season due to late arrival and hard ice conditions in Argentine Islands area. In time of cameras establishing in all colonies the penguine chicks were in the nests already. We expect to receive photo sequences for all breeding activity the next season in 2016/2017. The training of winterers-biologists has been provided for CEMP rules activity and for monitoring that can assist with camera data validation.

During the last years, a large amount of information was gathered and shared in one unique project for the development of a representative system of MPAs in Domain 1. This process integrates, compiles, analyses and exposes a large amount of information, not only contributing to the best science available but also providing a platform for the sharing and visualization of information, further improving the decision making process. Data was shared according to CCAMLR rules, providing the opportunity for other countries to develop their own analyses. During these years a solid foundation of collaboration and cooperation amongst Members involved in the development was built. However, there are still a number of Members currently doing research and/or undertaking commercial activities, that desirably could became involved in the development of the MPA proposal and contribute to the state of knowledge. This document highlights the progress made towards a common framework for Domain 1 MPA and further encourages the establishment of a cooperation network among countries.

This report is a presentation of environmental information on the Crozet oceanic zone that was obtained during the CROMEBA project (CROzet Marine Ecosystem Based Management). This project aims to determine the prerequisites at the environmental or biodiversity levels to propose new conservation measures that would expand geographically in the EEZ the actual National Marine Nature Reserve. The natural reserve is actually limited to the 12 nautical miles surrounding 4 islands of the archipelago.

This report follows the CCAMLR workshop on Planning Domain 5 with focusing on the Crozet islands oceanic zone (Koubbi et al., 2012).

This report is gives:

1.    A summary of the ecological characteristics of the Crozet oceanic zone on:

-        Pelagic and benthic biodiversity,

-        Marine birds and mammals tracked from the Possession islands,

-        Killer whales and sperm whales linked to fisheries observations.

2.     An ecoregionalisation combining:

-        The pelagic regions obtained from a classification of physical oceanographic features (fronts, retention zones, …) and chlorophyll-a which influence the pelagic food web including top predators,

-        Bathomes influencing benthic and demersal fish ichthyofauna,

3.     Recommendations for future researches and monitoring in the context of climate change consequences on subantarctic areas. 

Given their ecological and economic importance, understanding how climate change will affect krill resources and the marine ecosystem in Antarctic waters is critical. Previous research has demonstrated possible climate change impacts on krill habitat and growth. In this preliminary study, we assessed the potential consequences of these impacts for both the krill stock and its dependent predators using a peer-reviewed krill-predator-fishery ecosystem dynamics model. Initial results demonstrate the potential for projected temperature changes to negatively affect the individual weight and population biomass of krill as well as the abundance of krill-dependent predators. These outcomes have implications for our expectations about krill resources, and the larger Southern Ocean ecosystem. Further exploration is planned.

The analysis of euphausiid larvae collected during january 2011 in the Weddell Scotia Confluence region show a strong decrease in the abundance of Euphausia superba larvae and an increase in Thysanoessa macrura. Oceanographic conditions didn’t show any significant variations respect historical information. The analysis was conducted using cluster and correspondence analysis finding that the associations of the different larvae and especies correspond to the available information. The densities observed during the cruise were compared with densities obtained in 1981 and 1995 calculating expected values at a fixed grid of points. Significance of the differences was established using a binomial test on their signs.

Antarctic krill is a key species in the Southern Ocean food web and is also the target of the greatest fishery in Antarctic waters. Management of the fishery is based on a precautionary catch limit, representing 0.11 the allowable catch limit for CCAMLR Area 48, and further divided by subarea. Despite that the fishery is operating in the Antarctic Peninsula area since 1980s, the spatial and temporal pattern of the fishery is only described in meso to macro scales (>>10⁴ km²). Here we present a novel analysis to identified fishing grounds, using statistical analysis of hotspots, in this case, fishing hotspots (FH), combined with a temporal analysis to assess persistence of these FHs. Results indicate that the fishery is presenting consistent FH across years, particularly during those years when the precautionary catch limit is reached. These events occur mainly in the centre of the Bransfield Strait and the northern section of the Gerlache Strait, and have a duration of 3 to 5 months. FH identified are small, equivalent to a circle of radius 25 km, and have a high catch density (>10 ton∙km^-2) during years when the catch limit is reached. The analysis show that the krill fishing fleet is concurring to know fishing grounds year after year, where they obtain high catches, and that the catch density (ton∙km^-2) inside the FHs is correlated with the total catch obtained, suggesting its use as an index of krill abundance in an area.

We studied Ross Sea killer whales (RSKWs; Orcinus orca, Antarctic type C), a fish-eating ecotype, in McMurdo Sound, Antarctica, during 7 seasons, over a 14-year period from 2001/02 to 2014/15. Using photo-identification methods, we identified 352 individual RSKWs in the Sound and up to 175 there annually. Despite high turnover of different whales between years, we used a Bayesian mark-recapture approach to identify a seasonal ‘resident’ population with an average annual abundance of 55 individuals (95% probability = 44-68) that exhibited strong inter- and intra-annual site fidelity, with individuals resighted over 2-14 years. Contrary to recent reports that commercial overfishing of Antarctic toothfish (Dissostichus mawsoni) may have led to a marked decline RSKW numbers in the southwestern Ross Sea, our analysis suggests that at least the resident killer whale population in McMurdo Sound is stable with the average annual estimated number of deaths (= 2.4, 95% probability = 1.2-4) being balanced by the estimated number of recruits (= 2.6, 95% probability = 0.9-4.4).

At the close of the Commission for the Conservation of Antarctic Marine Living Resources meeting in 2015, New Zealand and the United States introduced a revision to the proposed Ross Sea Region Marine Protected Area (RSRMPA) that included the addition of a Krill Research Zone (KRZ). A central aim of the proposed KRZ is to enhance research opportunities within the RSRMPA. To provide a background for this future research, we reviewed previous scientific work relevant to the proposed KRZ, focusing primarily on krill and krill-dependent predators. Here we provide a summary of that review, which demonstrates the potential ecological importance of the proposed KRZ and gaps in our knowledge of the area. Our review further validates the opportunity presented by the proposed KRZ for future scientific research.

We present a Stage-2 strategy for in-season feedback management (FBM) of the krill fishery in Subarea 48.1.  This strategy is a combination of two strategies that were separately proposed to the WG-EMM in 2015 and is based on a broad foundation of work undertaken to address a suite of action items specified by the WG-EMM.  A decision rule to adjust catches in groups of SSMUs (gSSMUs) is central to the strategy proposed here.  In “plain English” that decision rule has four components.  1) If penguin recruitment is expected to be sufficient for population maintenance, CEMP monitoring indicates acceptable predator performance during the current breeding season, and krill biomass has increased during the present summer, the local catch limit will be increased.  2). If penguin recruitment is expected to be sufficient for population maintenance but CEMP monitoring indicates a poor breeding season or krill biomass has not increased during the summer, the local catch limit will not be adjusted.  3) If penguin recruitment is expected to be so poor that the population will decline even if adult survival through the forthcoming winter is very high, the local catch limit will be decreased.  4) If penguin recruitment is expected to be so poor that the population will decline even if almost all adults survive through the forthcoming winter, the local catch limit will be set to zero.  Implementation of the FBM strategy proposed here includes defining a base catch limit for each gSSMU (there are various options for this), collecting data on predators and krill, delaying the start of the fishing season until this data-collection effort is underway, submitting the data to the Secretariat, increasing the frequency of catch and effort reporting by the fishery, having the Secretariat compute various state variables from the submitted data and applying the decision rule with the state variables relevant to each gSSMU, providing advance notice to fishing vessels about the outcomes of applying the decision rule, and adjusting the catch limit in each gSSMU.  A time line for this implementation process is proposed.  Adjusted catch limits would only apply for a single fishing season and the implementation process would restart every year.  We used historical data to conduct retrospective analyses of our FBM strategy for two gSSMUs.  These analyses demonstrate that local catch limits would have been decreased about half the time, particularly when penguin populations were known to have been in decline.  Local catch limits would not have been adjusted or might have been increased when penguin populations were stable or increasing.  The retrospective analyses also suggest that delaying the start of the fishing season but permitting some fishing to occur prior to the “adjustment date” can be a reasonable compromise between minimizing risks to krill-dependent predators and minimizing impacts on the fishery.  The FBM strategy proposed here is fully consistent with the agreed definition of a Stage-2 strategy, and we advocate that it be trialed in real life.

Here we compile three vignettes that, together, provide the basis for making upward adjustments to local catch limits for the krill fishery in Subarea 48.1.  We use the term local catch limit to refer to a catch limit that applies to a group of SSMUs (gSSMU), and the work presented here is based on the gSSMUs defined in another compilation of vignettes (AERD 2016a, pp. 3-13).  We propose upward adjustments to local catch limits as one component of a larger strategy for feedback management (FBM) of the krill fishery in Subarea 48.1 (see Watters et al. 2016).  Our proposal to make upward adjustments is founded on 1) a “stoplight” classification of predator performance to identify years when predator performance is good and suggest that upward adjustments of local catch limits may not negatively impact predator populations, 2) repeat acoustic surveys to identify years when local krill biomass increases during the fishing season, and 3) a decision rule that can be used to increase local catch limits when the stoplight is “green” and there has been a concomitant increase in local krill biomass. We demonstrate that a simple index based on normalized CEMP parameters can be used to categorize predator performance as good (“green-light”) or poor (“red-light”). The approach is relatively insensitive to missing values, agrees generally with expert opinion, and suggests that indices of foraging trip duration, fledge weight, and reproductive success are highly influential in determining a green- or red-light classification of summer predator performance. We then show that local estimates of krill biomass around the Antarctic Peninsula are spatially and temporally correlated. Such patterns suggest that repeat surveys of standard transects within gSSMUs can be used to characterize larger-scale patterns of krill abundance and detect within-season increases in krill biomass. Thus, a ratio of late to early summer krill biomass estimates can be indicative of “surplus” krill potentially available to the fishery. To capitalize on such surpluses, we propose a step-change decision rule to increase local catch limits.  Provided the stoplight is green, the ratio of late-summer to early-summer estimates of krill biomass from acoustics surveys provides a simple catch-limit multiplier that can increase a local catch limit if the biomass ratio is greater than one. We advocate real-life testing of the ideas proposed here to prove the concept; in particular it would be useful for fishing vessels to collect acoustic data on repeat transects twice per summer.