Preliminary assessment of mackerel icefish (Champsocephalus gunnari) in the vicinity of Heard Island and McDonald Islands (Division 58.5.2), based on a survey in July 2007, using the generalised yield model

A survey of mackerel icefish, Champsocephalus gunnari, was undertaken in Division 58.5.2 in the vicinity of Heard Island in July 2007 to provide the information for an assessment of short-term annual yield in the 2007/2008 CCAMLR season. This paper provides a preliminary assessment of yield for the area of Division 58.5.2 to the west of 79o 20’ E using standard CCAMLR methods. Evidence of strong 1+ year class recruiting to the population has led to an increase in the estimated biomass of mackerel icefish, and an increase on the recommended catch over the projection. Based on a similar cohort structure seen in the population in 2003, this estimate is likely to increase further as this cohort is more fully selected.