CCAMLR

The average CPUE values, annual and calculated for the periods of 1977-1986 and 1986- 1991 are considered. It is assumed that these values adequately describe trends in krill density fluctuations. Rather high stability of the values investigated is revealed. It is proposed that krill density of 170-200 g/m2 may be considered as an average characteristic value for the area 48. It was revealed, that interannual CPUEs variability is lower for the area 48 as a whole, comparing subareas, most probable due to the certain krill transport between subareas.

Diet sampling of Adélie penguins (Pygoscelis adeliae) was carried out at two colonies, in the Ross Sea, Antarctica, to study the feeding ecology of this species for the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) Ecosystem Monitoring Program. The study took place at Edmonson Point CEMP site over five years, 1995-97, 1999, 2001 and was extended to Inexpressible Island in 2001. Mean diet composition varied from year to year and between the two locations in 2001. Meal size for chicks was found to be higher during the crèche than the guard period and males were found to return with a larger mean meal weight containing more krill than females. The overall composition of diet varied between locations: mean weight of food and krill content were generally higher at Edmonson Point. In the guard period, mean weight of food was lower at Inexpressible Island. Mean content of Euphausia superba was significantly higher at Inexpressible Island while more E. crystallorophias was found in stomach contents from Edmonson Point.

This document outlines 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 planned survey will utilise a standardised design as adopted in previous B0 surveys in the CCAMLR Area and will use a similar methodology for collecting an analysing the data to that used on the CCAMLR2000 survey. The survey will be conducted from a single ship and will consist of 15 parallel transects between 30° and 80°E. The survey design is presented to WG-EMM for their comment so that any suggestions can be incorporated into the final design which will be presented to the Working Group in 2005.

This list of publications is for information only; it comprises a set of BAS papers that have relevance to the work of WG-EMM, but which do not relate directly to the current agenda.
These papers were produced by two BAS core funded science programmes: Dynamics and Management of Ocean Ecosystems (Principal Investigator: Eugene Murphy; Project Leaders: Phil Trathan and Jon Watkins); and, Albatross (Principal Investigator: John Croxall).

Dual frequency (120 and 38 kHz) acoustic surveys were conducted around the Willis Islands and off the Barff Peninsula, South Georgia, from a 59 foot yacht in January 2004. The purpose of the surveys was to determine krill density near shore, in regions that have not traditionally been surveyed by large research vessels, and to survey responsively in areas where adult Macaroni penguins provisioning chicks ashore were foraging. Despite its relatively small size, the yacht (Golden Fleece) proved to be well suited as an acoustic survey platform. The echosounder transducers were deployed on a removable scaffold-tubing frame midships. With sails up the yacht had good roll stability and useable data were collected in seastate 6 with winds up to 30 knots and swells of approximately 2.5 m at survey speeds of up to 7 knots. Echo intensity data were scaled to krill density using a target strength determined from the length distribution of krill sampled from fur seal scats at Bird Island (mean krill length 53.13 mm, TS = -38.43 dB kg-1). Mean krill densities were 7.1 g m-2 off the Barff Peninsula and 5.7 g m-2 around the Willis Islands. Krill densities in both regions were low compared to time-series of observations from the past 20 years. A low density was perhaps not unexpected in line with recent cyclical patterns in density but may have been exacerbated by the presence of a large iceberg (40 miles by 30 miles) aground on the shelf edge to the north east of South Georgia that may have been blocking the influx of krill. In conclusion, acoustic surveys from small vessels enable data to be collected from regions where large vessels cannot operate safely, and offer flexibility to sample reactively on time scales that cannot always be accommodated under the scheduling constraints of multidisciplinary cruises. Combination of data from small vessels operating near shore with data collected over more extensive, off shore areas by large ocean-going research vessels will provide a more comprehensive understanding of the prey field available to krill predators.

In the southwest Atlantic sector of the Southern Ocean, temporal variability in the physical environment has been recorded since the early part of the last century. For example, ocean temperatures are known to vary both between seasons and between years. Time series analysis of sea surface temperature at South Georgia shows the presence of high levels of autocorrelation, with periodicity evident in temperature anomalies at lag periods of approximately 3 to 4 years. Crosscorrelation analyses with temperature anomaly data for the El Niño 4 region in the Pacific show that variability at South Georgia also reflects temperature fluctuations in the Pacific, with the Pacific leading South Georgia by approximately 3 years.
Biological variability is also apparent at South Georgia, being evident in data from a suite of top predators as well as in data from fish and Antarctic krill. Increased krill biomass appears to coincide with cold anomaly periods. In contrast, periods of reduced predator breeding performance are strongly correlated with warm anomaly periods, but lagged by a number of months. For some predators the most critical periods appear to be prior to the breeding season during the summer and early autumn of the preceding year. Thus, gentoo penguins (Pygoscelis papua) show a strong negative relationship between the number of chicks fledged and sea surface temperatures in the preceding February some 12 months earlier. Antarctic fur seals (Arctocephalus gazella) show a similar negative relationship between the number of pups surviving at birth and the temperature 14 months earlier in the preceding November. Such relationships with the physical environment most likely reflect prey (krill) availability. However, the full explanation of the observed relationships requires a more detailed understanding of the temporal and spatial interactions between predator demography and foraging dynamics, prey biomass and recruitment, and environmental variability.

Labelled water methodology was used to quantify energy expenditure during lactation and energy gain during the post-breeding aquatic phase in Southern elephant seal females at Stranger Point, King George Island (25 de Mayo). During lactation females spent a mean of 6021±1365 Mj, which resulted in a loss of 35% of the initial mass, comprising 63% of initial body fat and 20% of initial body protein. During the 58±5.4 d post-breeding foraging period, females gained 135±39 Kg, which allowed them to recover an average of 55% of the mass, including 46% of the fat, 71% of the protein and 47% of the energy lost during lactation. Neither the mass nor the energy lost during lactation were related to those gained while at sea. However, protein loss expressed in absolute terms or as a proportion of that present at the beginning of lactation explained about 50% of the variation in the protein gained during the post-breeding phase. This might indicate the presence of a mechanism favouring an increase in lean tissue during post-breeding.
Daily energy requirements for an average sized female during the post-breeding aquatic phase were estimated at 96 Mj. Estimation of prey consumption varies according to assumptions about diet composition. On a basis of 450 females, the total biomass of fish and squid consumed by the breeding group, assuming a diet composed of 75% cephalopods and 25% fish, was estimated at 521 t and 174 t respectively for the period examined.

Many international conservation treaties, non-binding agreements and other instruments that have relevance to marine protected area (MPA) development provide for action to be taken globally, and thus include Antarctica within the scope of a worldwide system of marine protected areas. However, depending on their specific provisions, full application in Antarctic waters may be difficult, inappropriate or even impossible because of the area’s unique political situation and existing regimes. It is concluded that although direct application of other international conservation agreements is in most cases unlikely to be feasible, efforts should be made to apply within the Antarctic Treaty System (ATS) certain principles and requirements agreed under instruments with global purview. These include the formulation of guidelines and criteria for MPA establishment, the consideration of marine protection as a separate, but linked issue to protection of other environments, and the development of more specific guidelines on the timeframe in which these should take place. In addition, the consideration of Antarctic waters in parallel with global work to develop high seas protected areas should be undertaken to achieve the goal of a global, representative system of MPAs, of which Antarctic MPAs should be an important component.

Observers on krill vessels fishing around South Georgia in the 2003 fishing season recorded fur seal captures by some krill fishing vessels. These captures can be attributed to the absence of effective mitigation measures (escape panels in the nets) and lack of experience of crews new to the fishery. Experienced vessels, employing effective mitigation measures, caught no seals. Although these levels of seal mortality are unlikely to impact significantly on fur seal populations, it is clearly important to have observers on krill vessels monitor the effectiveness of mitigation measures as well as to collect other biological data.

The USSR has fished in the Atlantic Sector of the Antarctic for three living marine resources: whales, krill and fish. In order to provide the fisheries with rational database the AtlantNIRO vessels conducted fishery and scientific studies. Investigations on whales were commenced in 1960. There were collected a big set of statistical and biological data on embryos growth rate of sperm whales, pigmy blue whales, southern baleen whales, physiological structure of the females share in the aggregations of various whale species, migrations etc. which is widely used for correct stocks evaluation and population dynamics. Using information collected by whalers, the world krill fishery was commenced by the AtlantNIRO vessel “Muxun” in 1961. From 1961 to 1970 eight scientific research and fishery voyages to the ASA were undertaken, from 1971 to 1980 – 25 voyages, from 1981 to 1989 – 22 voyages. For all the period of studies in the ASA an enormous primary database was collected by AtlantNIRO and VNIRO. Investigations of Antarctic fish were started by RV "Academik Knipovitch" in 1967. The main purpose of the researches was ecology of the commercially important species, stock and recruitment assessment and search for the new resources. Since 1960 AtlantNIRO’s contributions in the study of all three resources: whales, krill and fish, were very important, unique and may be used for oceanic ecosystem better understanding and protection and for planning and development of sustainable fisheries as well.