CCAMLR

On the ground of trawling of Ukrainian vessels made near the South Georgia from 16 June till 15 August 1995 peculiarities of krill distribution, their characteristics including time stability (tolerance), are examined, calculations of biomass and krill commercial concentrations values are given.
Interannual changes in some indices of krill fishing Resources in this subarea from 1985 till 1995 undergo analysis.

This paper presents a summary of the foraging locations of the Ad6lie penguin at 7 widely spaced locations along the coast of Eastern Antarctica between 55°E near Enderby Land and 175°E in the Ross Sea region. Birds feeding chicks regularly travel 100-120km offshore to the continental shelf and return with krill. The pattern of foraging is similar between sites. The potential for overlap with the krill fishery occurs where ice conditions permit the fishing fleet to cross onto the continental shelf. Observations at Casey and Dumont D'Urville from one season suggest such an overlap may not occur at these sites in normal ice years. It is suggested that an understanding of the potential for over lap between the areas of foraging of the birds and fishing be established by tracking before a decision is taken to establish new CEMP sites.

A time-dependent, size-structured, bioenergetically-based model was developed to examine the growth dynamics of Antarctic krill, Euphausia superba. A system of coupled, ordinary differential equations was developed to describe the growth of krill between 2 and 60 mm. The metabolic processes included in the model were ingestion, assimilation efficiency, a baseline respiration. respiratory losses due to feeding and digestion, and an activity-based respiration factor. Positive net production resulted in the transfer of individuals to the next highest size class (growth), whereas negative net production resulted in transfer to the next smallest size class (shrinkage). Size-dependent parameterizations of model coefficients were constructed from an analysis of field and laboratory measurements provided in the current literature. The model was forced with an environmental time series of food (pelagic phytoplankton concentration) that was derived from data sets collected west of the Antarctic Peninsula. Three time series were created to represent high, low, and intermediate food conditions with the high and low conditions representative of phytoplankton concentrations observed on the inner and outer shelf, respectively. Simulated growth rates during the spring and summer for all size classes were consistent with published growth rates; however, winter shrinkage rates were too large. Although the use of a seasonally-varying respiration activity factor (reduced winter respiration rates) resulted in winter shrinkage rates of adults that were consistent with observations of experimentally starved individuals. the annual change in length of specific size classes was still inconsistent with observations. Subsequent simulations were designed to examine the effect of the ingestion of sea-ice algae in the late winter and early spring. The annual growth cycle best matched observations with reduced winter respiration rates and ingestion of sea ice algae, particularly for larval and subadult krill (

The krill-predator modelling calculations of Thomson and Butterworth (1995) are extended to take account of a number of the suggestions made at the 1995 meeting of the CCAMLR Working Group on Ecosystem Monitoring and Management. The resilience of the Antarctic fur seal population to krill harvesting is found to be strongly dependent on the estimate of the maximum annual growth rate (R) which the population can achieve. For R=10%, it is estimated that a krill harvesting intensity rate γ of slightly more than 0.1 would be required to reduce the seal population to half its pre-exploitation level. Similar calculations are initiated for the black-browed albatross, but require the separation of fishery-related mortality effects from overall survival rate data before they can be taken further.