The swordfish fishery has expanded rapidly in the past few years off eastern Australia with an annual catch now of ~2400 tonnes. When the fishery first began AFMA set a ‘trigger’ point of 800 tonnes, after which they would review the amount of fish taken. Similar rapid growth has been reported for the fishery for swordfish off Western Australia where the catch is now at ~1000 tonnes. Added to this is the developing New Zealand fishery now also reaching 1000 tonnes. This last point is relevant in that recent genetic evidence indicates a single stock encompassing all three fisheries (Reeb et al 2000). There is an urgent need, therefore to determine whether these catches are sustainable. However, the population parameters from which accurate stock assessment can be made have not yet been determined for the Australian region. To this end Eastern Tuna MAC and SWTBF MAC listed age and growth determination as priorities three and one respectively in their list of ten priority research issues. The latest meeting of the Standing Committee on Tuna and Billfish (SCTB 13) held in Noumea noted the increase in swordfish fishing in the Western Central Pacific Ocean. They listed age and growth as a priority research issue for this species.
Assessments require input data on mortality, longevity and age structure; estimates that can be obtained from age and growth studies. There is a clear need therefore, for an age and growth study of this species. However, without validation over a number age classes, incorrect interpretations have lead to the wrong decisions by management. Therefore, before such an ageing study is begun the first priority is validation of the annual cycle of growth. With appropriate validation a length at age key, which is presently lacking, could be provided.