CCAMLR

A revision of the research plan for the Spanish exploratory longline fishery for Dissostichus spp in Divisions 58.4.1 and 58.4.2, submitted to the XXXI-WG-SAM, taking into account the suggestions made by the Working Group is presented. Two methods to estimate the local biomass of the toothfish are proposed, a depletion experiment together with the tag of some specimens using the DeLury model and the tag-recapture estimates using the Simple Petersen model.

To evaluate the potential success in achieving the objectives three study areas with high historical effort have been selected in different SSRUs with four different scenarios related to the extent of the area . The regression coefficients between the CPUE and the cumulative catch seem to be a practical way to stablish the area (10 nautical miles) and the minimum effort (0.3 k/hook) to perform the depletion experiment. Historical recaptures of Spanish tagged toothfish were examined within these areas and Subareas/Division (88.1, 88.2, 58.4.1 and 58.4.2). Results strongly related to the effort made within those areas suggest that the likelihood of achieving the objectives with this research plan is high.             
 

Waters around South Georgia are amongst the most productive in the Southern Ocean, and support internationally important fisheries. However, there is significant inter-annual variability in fish stocks, and some species have failed to recover from historical overfishing. Dispersal and retention of the planktonic stages (eggs and larvae) of marine fish can play a key role in the maintenance of adult stocks. Here we use a numerical modelling approach to examine the influence of oceanographic and life history variability on the dispersal and retention of two species of Antarctic fish: Champsocephalus gunnari (mackerel icefish) and Notothenia rossii (marbled rockcod). Mean retention of N. rossii larvae was predicted to be 5.3%, considerably lower than that of C. gunnari (31.3%), a difference related to the longer planktonic period of the former. Such apparent loss of larvae from local recruitment grounds may contribute to the failure of the N. rossii population to recover from its collapse in the 1970s. However, retention of both species showed high inter-annual variability. Dispersal and retention of C. gunnari were strongly influenced by location of the spawning site, with the greatest contribution to overall retention from spawning sites on the southwest South Georgia shelf. In addition, a consistent feature in C. gunnari was a lack of larval exchange between the proximate South Georgia and Shag Rocks shelves, regions separated by only 240 km. Our findings provide insights into the demographic dynamics and connectivity of C. gunnari and N. rossii populations at South Georgia in relation to prospects for recovery and ongoing responses to environmental variability and change in the region.

We studied the annual distribution, activity and breeding foraging trips of the sibling species of giant petrels, Northern Giant Petrel Macronectes halli and Southern Giant Petrel Macronectes giganteus from the  Crozet Islands (46°25'S; 51°51'E) where the 2 species breed sympatrically and Kerguelen Island (49°19'S; 69°15'E where Northern Giant petrels breed). Distribution and activity data were provided by GLS loggers (Global Location Sensing), and detail of breeding foraging trips were provided by ARGOS PTT. In order to assess differences in bycatch susceptibility, comparisons were made between species, sexes, stages (adult breeding, adult non breeding and juveniles) and sites. Activity patterns were investigated using GLMM and distribution ranges were determined using kernels analysis.

Overall, in adults, all stages remained close to nesting sites, during and outside the breeding season, while juveniles dispersed throughout the southern ocean. In adults, the intersexual differences were higher than interspecific ones, with females showing a greater distribution range than males in both species. Females also spent more time sitting on the water than males, particularly during wintering months. These results have important conservation implications, with males and females facing different kinds of threat in relation to their at-sea behavior. Adults, especially males, are more likely to be threatened by toothfish longline fisheries on shelf area of EEZs, and adult females as well as juveniles, are more likely to overlap with high sea longlining such as tuna fisheries.

This paper summarises the data collected by National and International Scientific Observers operating in the Convention Area on board longline and trawl fishing vessels during the 2011/12 season.  Only data processed by the Secretariat up until 21 September 2012 has been used in this paper, covering longline observations in Subarea 48.4, 48.6 and Area 88, and trawl observations in Area 48 and Division 58.5.2.  This paper will be updated in full prior to the start of WG-FSA when all of the available data had been received and processed.

The material obtained between 1986 and 1991 has allowed to study the pattern of geographical and depth distribution of Pseudochaenichthys georgianus in the area of Scotia Arc Islands and on shelf of South Georgia Island. In the Antarctic colder waters in the Palmer Archipelago there were mostly young, small fishes. They have stomach filled well with krill so swim probably to match with distribution of krill, which flow further to North and East with geostrophic currents. Following after them, with stomach often full of them, they became large, so the numbers of small individuals are disappearing farther from continent. Their gonad are more developed as the temperature further from continent get warmer. Finally at the end of Scotia Arc Islands - at South Orkney, P. georgianus are large with gonad ready to spawn, and mostly concerning on reproduction, they do not feeding, so they do not have reason to follow after krill driven to the East to deep open Scotia Sea.

In vast Antarctic Zone, enlarged by ice cover species are distributed into age groups separated geographically: first age group as was not in sampled area, have to be assumed to be near or under ice feeding on juvenile krill and fish; age 2 with 3 are in the South Shetlands; age 4+ are accumulating at South Orkney. While on shelf of one, small sub-antarctic island the group ages of P. georgianus are by time separated in a patterns of strong – week cohorts: age group of 4 is separated from the 2th by low numbers fish in previous age group 3. This may save them before feeding of own younger fish – common fish behavior among predators.

At South Orkney there are no small fishes. After hatching in cold winter waters as coming summer warm them, they swim upstream (as young fish usually do) to colder water of Palmer Archipelago to have more efficiency in food assimilation. This behavior save them before to be driven to open pelagic water and ensure good reproductive success as old fish drifting to warm water to gonad develop and to spawn.

At South Georgia similar pattern exist in the distribution of P. georgianus. Large specimens were closer surface near Eastern shores of South Georgia where water is warmer and sheltered before to be driven to Eastern large pelagic sea. After spawn young postlarvae swim upstream to the West, to the deep and cold waters. Spawning, feeding, diurnal and another migrations means changes of environments and physiology - events that have appropriate marks in the otolith microstructure.

The development of methods to estimate unaccounted fishing mortality from lost fishing lines requires an estimate of the number of lost hooks that are attached to sections of line. In 2011 hook loss data was provided by 21 of the 34 vessel/fishery reports with an estimated 317920 hooks lost attached to sections of lines.  In 2012 15 of the 26 vessel/fishery reports provided non-zero data with an estimated total of 313548 hooks lost attached to sections of line. In exploratory fisheries, particularly those in data-poor regions, the requirement and appropriate mechanism for reporting these data may need to be reiterated in order to achieve a greater level of engagement with the requirements to complete the C2 data reporting form.

In 2012 data on beach surveys, debris associated with seabird colonies, marine mammal entanglements and hydrocarbon soilings were received from South Africa, the United Kingdom, and Uruguay.  Non-fishing items such as plastics, packaging materials and wood remain the most common type of debris items found in beach surveys.  The fishing items found were mostly from longline and trawl origins. Plastic packaging bands continue to be found in beach surveys, however, for the first time since these surveys originated in 2002 there have been no closed bands found at any of the three sites.  The amount of debris in colonies of grey-headed albatrosses, wandering albatrosses and black-browed albatrosses at Bird Island decreased significantly since 2011, with the major category of items found being plastics.  The amount of fishing related items (fishing lines and hooks) found in wandering albatross colonies remains the foremost debris item found in each season. The number of marine mammal entanglements decreased since 2011 with packaging bands and fishing gear the main entangling materials. There was only one new hydrocarbon soiling reported from King Edward Point in 2010.   The results of the ongoing monitoring of marine debris in the Convention Area suggest that while the type and amount of debris varies from annually there have been no long-term trends over the past decade.  Extrapolation of these findings to areas outside Area 48 are limited by data on long-term monitoring of marine debris and Members with opportunities to engage in such monitoring are encouraged to submit data to the Secretariat.

Since its inception in 1992 the CCAMLR Scheme of International Scientific Observation  the complexity of documenting procedures, variety of sampling requirements and associated data management have all increased. Given  the likely continued increase in complexity it is essential to have processes in place to review, revise and adapt existing procedures to ensure that the scheme overall remains robust.   This is a scoping paper to initiate discussion on a task group with representation from all interested parties (including WG-FSA, WG-EMM, WG-IMAF and SCIC) to review observer sampling requirements across all fishing sectors and conservation measures.

This paper has been provided by the Secretariat to assist WG-FSA and the Scientific Committee to give additional consideration, at their 2012 meetings, to methods to estimate trends in IUU fishing and estimates of IUU catches, including further consideration of the recommendations of JAG.  The paper includes:

1. consideration of patterns and activities associated with IUU fishing in the CAMLR Convention Area
2. the methodology used in estimating IUU catches and trends in the CAMLR Convention Area
3. a program of work for consideration aimed at improving the quality of information available to estimate IUU fishing trends and catches in the CAMLR Convention Area.

This paper summarises fishery-related scientific research notified under Conservation Measure 24-01 for 2011/12 and 2012/13.