Age, growth and size at sexual maturity of Macrourus carinatus from the CCAMLR fisheries in division 58.5.2

Estimates of age and growth were determined from 156 Macrourus carinatus otolith samples collected during two research voyages to Heard and McDonald Islands (Division 58.5.2) in 1992 and 1993. The estimated range of ages was 4 – 25 years. von Bertalanffy growth parameters were calculated for both sexes combined, resulting in values of: L8 = 635 mm, K = 0.088 and t0 = -1.8. The size at sexual maturity of M. carinatus was determined from 162 specimens collected during commercial fishing operations in the Heard Island region in 2000. The size at which 50% of the fish population is mature, L50 was 417 mm total length and the size at which 50% of the fish population have spawned for the first time, Lm50 was 512 mm total length. An updated length-weight relationship is provided from 633 specimens of M. carinatus collected from Heard and McDonald Islands and Macquarie Island. No difference was evident in the length-weight relationship from the two regions. Otolith and body size relationships were also calculated for M. carinatus from Division 58.5.2.