CCAMLR

The Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) is currently considering plausible models of the Southern Ocean ecosystem within the Working Group on Ecosystem Monitoring and Management (WG-EMM). While recognised to be an important component of this ecosystem, particularly with regard to food-web structure and function, squid have rarely been included in previous ecosystem models except perhaps to assess their potential impact as predators of Antarctic krill. This paper describes properties for three groups of squid that may be included in future ecosystem models of the Southern Ocean: onychoteuthids, ommastrephids and small – medium nektonic squids. Important ecological differences are considered to exist among these three groups (e.g. spatial and depth distribution, ontogenetic and vertical migrations). Furthermore, this paper reiterates findings from previous studies that squid should no longer be modelled as specialist predators on Antarctic krill.

This paper reports on the intersessional activities of the Steering Committee of the “Workshop on plausible ecosystem models for testing approaches to krill management” in preparation for the workshop at WG-EMM 2004. The overarching Terms of Reference are (i) to review the approaches used to model marine ecosystems, (ii) to consider plausible operating models for the Antarctic marine ecosystem, and to advance a program of work to develop and implement operating models to investigate the robustness of different management approaches to underlying uncertainties in the ecological, fishery, monitoring and assessment systems. As agreed at WG-EMM in 2003, intersessional activities have included (i) provision of advice on the potential contributions from experts in preparation for the workshop and in participating in the development of models at the workshop, (ii) a review of relevant literature and information on the development of ecosystem models elsewhere as per the first term of reference, (iii) compilation of a catalogue of available software and other simulation environments for ecosystem modelling, (iv) preliminary consideration of the requirements for datasets, estimates of parameters and other aspects related to the second term of reference, and (v) preliminary outline of the aims and specifications for ecosystem modelling as it relates to the development of management procedures for krill. The results of this work are outlined. Also provided in this report is a draft agenda for the workshop.

CCAMLR requires an assessment method for recommending a subdivision of the krill catch limit in Area 48 that will be highly likely to achieve the objectives of the convention despite the uncertainties in knowledge. This will be part of the management procedure governing the krill fishery. The agreed workplan for developing a management procedure includes the evaluation of candidate management procedures in a simulation framework, using plausible models of the Antarctic marine ecosystem. This paper develops a framework for erecting such models. It is divided into three main parts, addressing different aspects of model development. Part 1 outlines the issues to consider in assessing the requirements of plausible models. Part 2 discusses the general model requirements while Part 3 presents a possible framework for developing ecosystem models to evaluate krill management procedures. The first section of this part outlines a conceptual approach to the taxonomic/biological elements of a model and the manner in which linkages between those elements might be considered. The second section details a model framework for characterising (i) the different taxa depending on the status of knowledge and their importance for understanding the ecosystem effects of fishing, (ii) important physical processes that will influence the system and (iii) the fisheries. In developing these parts, the paper highlights areas that may be necessary to be considered by WG-EMM in the development of plausible models.

Standardized krill net sampling surveys were conducted in the Lazarev Sea (Subarea 48.6) in April 2004 and in the Elephant Island area (Subarea 48.1) in January and February/March 2004. Krill densities in the Elephant Island area were below the long-term average which mark a substantial decline after the good krill years in 2001 and 2002. Krill density was lower in the Lazarev Sea, even after taking substantial day/night differences in the catches into account. Recruitment indices of one-year- old (R1) and two-year-old krill (R2) were calculated for both areas, showing low values for R1 and high, but different values for R2. Spatial distribution of krill density and size/age classes is discussed for the Lazarev Sea. Information are given on the development of maturity stages and “re-juvenation processes” after the spawning season. Distribution and density of krill calyptopis and furcilia larvae are provided for the Lazarev Sea.

During the 1995/96 and 1996/97 summer seasons the foraging pattern of the Antarctic Shag Phalacrocorax bransfieldensis was studied by direct observation on individuals breeding at Harmony Point, Nelson Island, South Shetland Islands. During pre-laying and incubation individuals of both sexes usually foraged once a day; females early in the morning and males when their partners returned to the nests. During the rearing period the parents incremented the number of daily foraging trips usually alternating the time at sea. Compared to the incubating period, when rearing chicks individuals of both sexes reduce the extension of the foraging trips which in years of scarce food availability may no result in reducing the daily total time spent foraging due to the marked increment in the number of trips required to cover the demands at the nest. Rearing individuals respond to increasing energy requirements at the nest (i.e. as chick grew older or at increasing number of chicks at the nests) by incrementing the number of daily foraging trips and the time spent foraging. The information obtained suggest that the Antarctic Shag display mechanisms tending to buffer variable food abundance or energy requirements at the nest. The possibility of using the foraging parameters considered in this study in monitoring programmes is discussed.

The rationale for the proposed main review of the Scientific Observer Manual and a plan of intersessional work on the subject during 2004 are presented.

The Ross Sea Shelf Ecosystem (RSShelfE) offers the last chance to understand ecological processes in a system where both top-down and bottom-up forcing are still intact. Elsewhere in Earth’s oceans the systems used for understanding ecological processes and fishery effects all have lacked significant, natural top-down forcing for such a long time that it is a concept rarely considered by researchers who currently investigate open-ocean systems. Herein, the importance of top-down forcing in pelagic and neritic marine ecosystems is reviewed with concrete evidence given for its existence in the current functioning of the RSShelfE. In spite of this unique evidence for the Antarctic region, much remains to be learned about cross-component interactions in the Ross Sea system. Should the RSShelfE be un-naturally altered, an easy accomplishment given increasing fishery pressure, we will have lost the last opportunity to understand the processes that take place in a healthy, complete marine ecosystem.

At the 2003 meeting of the Commission, the Terms of Reference (TOR) for the Advisory Subgroup on Protected Areas were endorsed by the Commission (CCAMLR XXII (paragraph 4.26). One task, which was directed to the intersessional work of the Subgroup, was TOR (ii) “to revise and keep under review, as appropriate, guidelines for the production of maps of protected areas relevant to CCAMLR”. The following revision of Conservation measure 91- 01, Annex 91-01/A (2000) addresses the topic of maps. Changes were made to section A2 (Maps).
The Subgroup on Area Protection has had the opportunity to review the map guidelines produced by the Antarctic Treaty’s Committee for Environmental Protection (CEP) entitled “Guidance Notes for Producing Maps for Inclusion in Management Plans” (Report of CEP-1 Appendix 3). These guidelines provided an excellent framework for map production and were used as a starting point. Also, other items specific to CEMP sites and marine areas were included in the following revision of guidelines. The revision of the CEMP site mapping guidelines includes, for example, the addition of recommendations for including or identifying specific essential map and topographical features, natural features, anthropogenic features, boundary delineation, and general guidelines for improving map quality (i.e., verifying boundaries using GPS, using SCAR approved legend symbols, etc.).

Last year we established a new, dedicated database to archive research survey data submitted to CCAMLR. This database is ‘event-driven’ – i.e. each survey can be characterized by a series of events (eg trawl, CTD, acoustic etc) and each event has a set of measurements (eg amount caught, conductivity at depth, density estimate etc). The development of the trawl survey components has been reported to WG-FSA, and progress on archiving the acoustic data is reported here. In addition to the developments to date, WG-FSA’s Subgroup on Fisheries Acoustics (WG-FSA-SFA) has discussed the possibility of archiving acoustic data from finfish surveys and this matter was further discussed at SC-CAMLR-XXII. The Secretariat has begun working with past and present conveners of WG-FSA-SFA to identify the group’s needs for data storage and analysis.

Correspondence on:
• Collaborative program by Ukraine and Bulgaria on research into gentoo penguin breeding biology at Vernadsky Station, Antarctic Peninsula (Ukraine) and Livingston Island, South Shetland Islands (Bulgaria) (see SC-CAMLR-XXII, Annex 4, paragraph 7.14);
• Notes on the collection of CEMP data at Bouvetøya.