Extension to the krill-predator modelling exercise

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.