682 



Fishery Bulletin 89(4), 1991 



Marlborough Sounds 



1 74' E 



D'Urville Island sites 



C " Northern Marlborough 

 Sounds sites 



Southern Marlborough 

 Sounds sites 



Figure 1 



Location of study sites in New Zealand. 

 Black circles indicate sites sampled in this 

 study; open circles indicate sites of mark- 

 recapture experiments done by Talbot 

 Murray (unpubl. data). The three regions 

 into which sites were grouped are in- 

 dicated for the Marlborough Sounds and 

 Stewart I. 



Auckland 

 North Island 



Stewart Island 



population parameters are required to manage the 

 fishery effectively. In this paper we assess the size 

 structure, age structure, and mortality of paua 

 populations. 



We estimate 'age' from growth rings in shells and 

 assess the usefulness of this ageing technique for paua. 

 This is potentially one of the most powerful tools 

 available for estimating growth and mortality rates 

 (Shepherd and Breen 1991). Cross sections of H. iris 



shells have obvious rings. These have previously been 

 used to estimate age and growth (Murray and Akroyd 

 1984, Murray 1986, Hahn 1989), but no verification has 

 been reported. Similar rings have been used elsewhere 

 to age abalones. For instance, rings in H. tuberculata 

 (in the English Channel) have been verified by growth 

 studies (Forster 1967, Hayashi 1980). Verification is 

 also reported in Japanese H. discus discus (Kojima et 

 al. 1977) and the Korean H. diversicolor diversicolor 



