CCAMLR

The purpose of this paper is to clarify the concept of “representativeness” in Marine Protected Areas (MPAs) design and to review discussions and agreements at CCAMLR meetings relating to its application to the designation of a representative system of MPAs in the Southern Ocean. In 2005, CCAMLR endorsed advice from the Scientific Committee, which noted that representative areas, defined as “areas that would aim to provide a comprehensive, adequate and representative system of MPAs to contribute to the long-term ecological viability of marine systems, to maintain ecological processes and systems, and to protect the Antarctic marine biological diversity at all levels” would contribute to furthering the objectives of CCAMLR.

The principle of representativeness aims to ensure that differences in particular ecosystems or habitats in a particular region are captured within a system of MPAs. A key part of the process of creating a representative system of MPAs is the identification of representative areas of biodiversity through biogeographic analysis in a systematic conservation planning process. The value of biogeographic analysis for representative Southern Ocean MPAs is reflected through CCAMLR’s commitment to bioregionalisation, and this analysis has subsequently underpinned the whole process of MPA development within CCAMLR. Thus, CCAMLR has extensively considered and refined the concept of representativeness in the past 10 years.

At the CCAMLR meeting in 2012, the Commission welcomed the offer of Germany to take the lead in developing a Weddell Sea MPA for consideration in 2014. Subsequently, the German Federal Ministry of Food, Agriculture and Consumer Protection tasked the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research to compile and analyse scientific data for identifying areas which require particular protection in the Weddell Sea. Work under this project started mid-April 2013. This progress report is based on WG-EMM-13/22 which was submitted to WG-EMM 2013 in Bremerhaven, Germany. Germany intends to update the Scientific Committee on the actual state of our project, particularly on the main proceeds of a national data workshop held in Bremerhaven early September 2013. The main objectives of this document are (i) to propose the planning area of our evaluation study, (ii) to provide an update on the data situation, (iii) to draw attention to the forthcoming (early April 2014) international expert workshop on the planning of a Weddell Sea MPA.

A multi-year plan for research by Japan and South Africa aimed at yielding a tag-based assessment of the Dissostichus resource in statistical Subarea 48.6 was adopted in 2012 and formulated in CM 41-04. This paper presents a revised work plan for the South African contribution to the second year of this research in 2013/14 and is to be read in conjunction with WG-SAM-13/11.

The local densities of Champsocephalus gunnari  observed in the 2013 survey are compared with those observed in 1994-1997. A significant increase in densities across 24 sites previously sampled was found. The comparison of the length distribution functions suggests that the stock depletion in the early 1990’s was due to recruitment collapse, probably a consequence of overfishing.

The stock of Antarctic toothfish in the CCAMLR subarea 48.4 was estimated using as the Petersen method as  640 tonnes. Application of the harvest rate used for D. eleginoides in Subarea 48.3 (γ = 0.038) gives yields of 24 t for the Antarctic toothfish in the region vs. previous estimation of 30 tonnes.

The present report re-analyses data regarding CPUE for both species of toothfish in northern area of 48.6 (SSRU 48.6A, 48.6G). This report is a re-analysis of the CPUE time series proposed in previous work (SAM 13/29) which includes all those comments and suggestions made in the last SAM meeting. Here, the  length of the line was used as effort unit and also high CPUE values reported by a Korean Vessel (Insung No 7) were further investigated by applying extreme value analysis. Antarctic and Patagonian toothfish presented a high proportion with sets in which both species are present, and thus, an analysis of catch intention was implemented by using multivariate statistical approach of the catch composition. Standardisation of CPUE was done by using Generalised Additive Models (GAM) considering temporal and location factors. A mix model using vessel nationality as random variable was also implemented.  These improvements did not change the CPUE time series in Antarctic Toohthfish and only produces minor changes in Patagonian toothfish. We believe extreme value analysis provides a useful tool to evaluate anomalous CPUE.  The same conclusion with previous work arise, the CPUE have little or none information as index of abundance and thus, it is highly recommendable to continue with the collection of the data by scientific observed and tagging and release program.

Information on biological aspects of the finfish catches obtained in the survey of BIP Dr.  E L  Holmberg, conducted around Shag Rocks and the South Georgias Islands in April-May 2013, is presented. A total of 25 tows were taken, catches comprised sixteen finfish species, being Champsocephalus gunnari, Chaenocephalus aceratus, Notothenia rossii, Pseudochaenichthys georgianus, Patagonotothen brevicauda guntheri and Gobionotothen gibberifrons, the most frequents. The highest fish densities were found in the shelf of the South Georgias Islands. Total lengths ranged from 4 to 55 cm, 7 to 63 cm, 9 to 51 cm, 31 to 78 cm, 11 to 20 cm and 4 to 43 cm for C. gunnari, C. aceratus, P. georgianus, N. rossii, P. brevicauda guntheri and G. gibberifrons, respectively. Males and females showed a similar population structure, in a relation 1:1 in all the species analyzed.

Two length-weight relationships were estimated for C. gunnari and C. aceratus; for specimens below and above 11 cm TL. Statiscally significant differences were found between them (ANCOVA p<0.05). Length at first maturity (L50) was estimated in 26.87 cm for C. gunnari for the pooled data. No significant differences were found between males and females. Juveniles of several species were present in significant numbers.

This report presents a summary of the work conducted onboard and a preliminary description of the results obtained during the research survey. The cruise started on april 26th and returned to Mar del Plata the 21st may 2013.

The work was conducted in the CCAMLR statistical area 48.3 and its main objective was to obtain information on the status of the stocks of Chamsocephalus gunnari and Notothenia rossii.