CCAMLR

A first estimation of the ρ conversion factor for the flow meter, used for converting volume into green weight, is provided.

Uncertainty related to estimates of krill green weight from catches has recently been an issue raised repeatedly within CCAMLR for a number of years, resulting in a modification to the C1 form implemented for the fleet in 2012. There are at present three Norwegian vessels operating in the krill fishery for Euphausia superba in the Antarctic. These vessels have in recent years contributed to 50-60 % of the total krill harvest, and reliable uncertainty estimates from these vessels will therefore be important contributions to an estimate of total uncertainty in catch weight. Here, we present the procedures for uncertainty estimation on board the Norwegian vessels, including how measurements are carried out in practice and transferred to the C1 forms. We also present a brief evaluation of results and procedures.

The US AMLR Program has established a 5 year winter oceanographic and biological sampling program to better understand winter conditions affecting the productivity and survival of euphausiids in a changing ecosystem. Oceanographic sampling includes hydrographic measurements as well as collection and analysis of water samples from fixed depths. Net tows for euphausiids and other pelagic zooplankton taxa are also collected. Here we present preliminary results  of a first 8 day shakedown cruise reporting the distribution, size and properties of krill and other euphausiids and present some data on water column properties. Future years will include more detailed sampling using a multi-net tucker trawl, ice cores for examination of ice properties, and continued development of genomic studies to understand links between pico-plankton and meso-zooplankton.

The level of observer coverage in the krill fishery and  the  scientific sampling undertaken are summarised.  During 2012 all 12 of the vessels that participated in the krill fishery carried observers for some or all of their fishing operations. From a total of 860 vessel days of fishing in 2012 observations of krill length measurements were collected on 375 ‘days’ and fish bycatch was measured on 554 ‘days’. Krill length-frequency distributions showed that the greatest variability in size structure occurred  in subarea 48.1 during 2012 when fishing occurred both in Bransfield Strait and to the west of the South Shetland Islands.  The 4901 fish measurements from 34 taxa  indicate the vast majority of fish caught as bycatch are <5cm in length.

In 2011/12, 12 vessels from five Members fished for krill in Area 48 and the total catch of krill was 161085 t (Subarea 48.1: 75630 t; Subarea 48.2: 29040 t; Subarea 48.3: 56415 t). The largest catch of krill by small-scale management unit was taken in ‘South Georgia East’ in Subarea 48.3 with a total catch of 50218 t.

So far this season (2012/13), 11 vessels from Chile, China, Korea, Norway and Ukraine have fished for krill in Area 48. The total catch reported to the end of May 2013 was 151161 t, 86% of which was taken from Subarea 48.1. At the time of preparing this report, the cumulative catch in Subarea 48.1 was 146474 t (94% of catch limit 155000 t) and that subarea was closed on 14 June 2013.

Six Members (19 vessels) submitted notifications to fish for krill in Subareas 48.1, 48.2, 48.3 and 48.4 in 2013/14. The total notified, expected level of krill catches is 545000 t. There were no notifications for exploratory fisheries for krill.

A great challenge for Southern Ocean ecosystem science is to assess the status and trends of Southern Ocean marine ecosystems overall, against which change in ecosystem structure and function can be unambiguously assessed in the future.  This challenge includes being able to assess the likelihood of different states in the future.  These requirements are needed by different bodies regionally and globally for making tactical decisions, such as catch limits and conservation requirements in the Commission for the Conservation of Antarctic Marine Living Resources, and to provide strategic advice, such as in the Intergovernmental Panel on Climate Change.  There are three subsidiary questions to this challenge:

1. How should status and trends in those ecosystems be assessed and reported and how will the likelihood of future states be assessed?
2. What are the gaps in knowledge that are required to be able to undertake these assessments?
   a.    what is the current status of Antarctic and Southern Ocean ecosystems overall?
   b.    what are the critical processes, mechanisms and feedbacks that directly influence the population responses of biota to change in their habitats?
3. What observations need to be taken that will indicate a change in state of those ecosystems and provide suitable input to, validation or correction of assessments?

This paper summarises international initiatives and their current activities aimed at delivering circumpolar ecosystem assessments.

In this study, we introduce the initial results from three seasons (2011-2013) of penguin observations made in the waters off the South Orkney Islands. The surveys followed pre-determined transect lines during five consecutive days within late January and early February. Three species of penguins were observed and Chinstrap penguins (Pygoscelis antarctica) dominated in numbers during all three seasons, with Adélie (P. adeliae) and Gentoo penguins (P. papua) only present in modest numbers. The average number of penguins observed per hour increased from year to year, with 7.8 ind/hour in 2011, 32.8 ind/hour in 2012 and 58.5 ind/hour in 2013. Different results also appeared when comparing data collected two times in the same area during the same survey. Future research will consider these results to the differences in study design, density of prey resources and relevant physical factors. This study is part of a larger program that aims to establish and build time series of environmental data, Antarctic krill (Euphausia superba) and krill predator’s abundance and distribution patterns in this area.

The pelagic trawlers involved in the fishery for Antarctic krill (Euphausia superba) apply different trawl designs. Very little information exists on the size selectivity of E. superba. Size selectivity describes a given trawls designs ability to catch different sizes of a population and is valuable information for the management of harvested marine stocks. Size selectivity data is traditionally collected during timely and costly fishing experiments in the field where one design is tested at the time. FISHSELECT is developed as an alternative method, and is based on thorough measurements of the morphology of the species in quest and the shapes of the relevant mesh types, to predict the size selectivity by mathematical modeling. After making modifications with the procedures in FISHSELECT to parameterize morphology, the method proved applicable to determine size selectivity in different trawl designs for E. superba. We present design guides that predict the basic selective properties for E. superba in all relevant sizes of diamond meshes 5 - 40 mm and the opening angles of 10 - 90 degrees. Our predictions are based on the species morphology only, and do not take into account potential behavioral effects. Finally, we discuss how our result can be utilized for management purposes to increase the understanding of the catching process of E. superba and the selective properties in different fishing gear.