CCAMLR

A survey of the Japanese R/V Kaiyo Maru was carried out to collect data simultaneously on ecological interaction of environment – Antarctic krill – whales in the Ross Sea and adjacent waters during December 2004 and February 2005. Transect lines along 165E, 175E, 180, 175W, 170W and 165W were investigated to cover hot spots which suggest high concentrated krill and whales such as the Scott Seamounts Island, the Balleny Islands, the shelf off the Victoria Land and the almost whole of the Ross Sea. The 175E and 170W lines, especially, were surveyed in detail from the surface to near the sea bottom from 60S to the edge of the Ross Ice Shelf on physical, chemical and biological parameters.

The distribution of krill females of the different maturity stages was considered to reveal the preferable bottom depths for the spawning. Calculations based on the three expanded scientific surveys and numerous data from observers revealed no statistically reliable tendency in the gravid females to move offshore to deeper waters. The possible reasons causing the spawning females distribution are discussed. It is assumed, that the most important factor determining gravid females distribution is food supply.

A key area of concern highlighted by the Scientific Committee of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) concerns the potential overlap of the krill fishery with the foraging area of land-based predators such as seals and penguins in the Antarctic Peninsula region. The dynamics of krill in this region are strongly influenced by advective processes. A key question is therefore whether or not limitations on fishing activities (reducing their economic efficiency) are necessary given that there is a flux of krill through this region with its islands habited by predator colonies. In order to estimate the krill production actually available for predator consumption, it is necessary not only to consider “snapshot” survey estimates of krill abundance in the vicinity of a breeding colony but also the flux of krill through such areas. This paper outlines a proposed spatial modelling framework that could be used to couple flux estimates with estimates of removals by both the fishery and predators, in an attempt to quantify what level and localisation of the fishing effort might impact the predators negatively. The approach described represents work still in progress as the focus thus far has been on first developing a model of the possible impact of pelagic fishing on seal and penguin colonies on the South African west coast. The latter ecosystem shares a number of common features with the Antarctic Peninsula ecosystem in that there is a substantial advective flux of either pelagic fish or of krill, with both species serving as dominant prey items for colonies of land-based predators in the region concerned. Subject to the availability of data from both predator studies and krill surveys, the West Coast model methodology could thus straightforwardly (initially at least) be adapted to the Antarctic Peninsula region. This would permit the evaluation of a wide range of management options pertaining to the issue of taking into account the needs of other species when setting precautionary krill catch limits at an appropriate spatial scale.

This document summarizes work that we completed after submitting background document WG-EMM-05/13. Our intent here is to augment and enhance WG-EMM-05/13, and the follwing text can be attached to WG-EMM-05/13 as its third appendix. To facilitate such attachment, we start the page numbering of this appendix at page 55. This appendix contains 1) example parameterizations and results for krill movement in the KPFM, 2) errata for the main text of WG-EMM-05/13, 3) errata for and extensions to Appendix 1 of WG-EMM- 05/13, and 4) a short, annotated script of S-plus commands that we hope to follow while demonstrating our KPFM to the WG-EMM and the Workshop on Management Procedures.

The CCAMLR has recognised the need to subdivide the precautionary krill catch limit for Statistical Area 48 amongst smaller spatial units in order to minimize the localized depletion of krill in predator foraging areas. These smaller spatial units, termed small-scale management units (SSMUs), have been defined, and six candidate procedures for subdividing the catch have been identified. It is now necessary to evaluate these procedures in terms of their likely effects on krill and predator populations as well as fishery performance. This evaluation must be conducted in the context of considerable uncertainty about how the krill-predator- fishery system operates. We describe a model designed to investigate the performance of these procedures and their sensitivity to numerical and structural uncertainty. The model is spatially resolved to the level of SSMUs and surrounding oceanic areas, and it includes the transport of krill between these areas. Krill and predator population dynamics are implemented with coupled delay-difference models, which are formulated to accommodate various assumptions about the recruitment and predation processes. The fishery is represented as a simultaneous and equal competitor for available krill. Straightforward Monte Carlo simulations are used to integrate the effects of numerical uncertainty, and structural uncertainty can be assessed by comparing and merging results from multiple such simulations. We present a range of performance measures that can be used to evaluate catch-allocation procedures and assess tradeoffs between predator and fishery performance. We provide basic instructions on running the model in S-Plus and illustrate its use. Finally, we conclude that although our model necessarily simplifies a complex system, it provides a flexible framework for investigating the roles of transport, production, predation and harvesting in the operation of the krill-predator-fishery system.

Data from individual hauls carried out by krill F/V “Atlantic Navigator” operating in three fishing zones were analyzed: Elephant islands zone (48.1), South Georgias islands zone (48.3) and South Orkney islands zone (48.2). The fishing season was extended from 19/2/04 (summer 2004) to 7/4/05 (early winter 2005) with a total of 251 days of effective fishing. Descriptive study of the fishery operation was performed for the two fishing systems used: conventional fishing system (CON) and the continuous fishing system with air-bubbling suspension and suction of capture (CFS). Individual haul data were analyzed to describe differentialy catch rates (catch per day and catch per minute) of the three different fishing zones studied. The total catch registered was 41837 tonnes: 50% of this capture was obtained at South Orkney islands zone. The highest catch rate were calculated for the same fishing zone with CFS (293 kg/min) during summer 2005. The biggest krill size also corresponded to this zone and season: 50 mm total length. Sexual proportion determined when possible (summer 2005) was determined: males 64,59%, females 28,00% and immature individuals 7,38%. Predominant colour of sampled individuals was determined IC for winter season 2004 and IIC and IIB for summer to winter 2005. All data was recorded under the CCAMLR Scheme of International Scientific Observation (SC-CAMLR, 1993).

This document updates plans by Australia to conduct an acoustic biomass survey for krill in CCAMLR Division 58.4.2 (the South West Indian Ocean Sector) in January-March 2006. The survey is intended to produce a new estimate of B0 for this Division so that a revised precautionary catch limit can be established by CCAMLR. . The survey will be conducted from a single ship and will consist of 11 parallel transects between 30° and 80°E. The survey design was presented to WG-EMM for their comment in 1995 and suggested improvements have been incorporated into the final design.

At the request of the Scientific Committee, the Secretariat has prepared a single reference document which provides guidelines for the submission of meeting documents to the Scientific Committee, WG-EMM and WG-FSA (including ad hoc WG-IMAF). In the Secretariat’s view, the guidelines would benefit from some standardisation of the Working Group-specific differences in relation to: submission deadline; exception to the deadline; and approach to accepting revised documents. Some changes are proposed to standardise these specific differences. These changes would simplify the procedures which participants to both WG-EMM and WG-FSA must follow. Standardisation would also simplify the Secretariat’s work in preparing information and documents for meetings. The Secretariat plans to submit a similar proposal to WG-FSA for consideration at its meeting in 2005.

The eighth complete consecutive season of data collection at Cape Shirreff has enabled us to examine trends in penguin population dynamics, as well as inter-annual variation in penguin diet, and foraging behaviour. The chinstrap breeding population at Cape Shirreff has continued to decline over the past six years, and is at its lowest size in the past eight years of study, and fledging success was poor compared to earlier years of study. The gentoo breeding population, in contrast, has remained relatively stable and had similar fledging success in 2004as the long-term mean. Fledging weights of both species decreased from last year, and were the lowest average weights seen over nine years. The diet of both chinstrap and gentoo penguins contained primarily adult female Antarctic krill, peaking in the 46-50mm range, continuing a four year trend of increasing proportions of female krill and increasingly larger krill. The diet of both species contained less fish than in other years on average. Total chick meal mass was larger for chinstrap penguins compared to the past seven years of study, primarily in the digested portion of the meal. The interpretation of these diet patterns may be aided by analysis of foraging location and diving behaviour data.

A Management Plan for designating Admiralty Bay and its surroundings as an Antarctic Specially Managed Area (ASMA), under Annex 5 of the Protocol to the Antarctic Treaty on Environmental Protection, was jointly proposed by Brazil and Poland, in coordination with Ecuador and Peru and voluntarily adopted by the ATCPs at ATCM XX (Utrecht, 1996). The document presented here is a revision of the former Management Plan, as required at ATCM XX.