McGarvey: Estimating emigration rates from marine sanctuaries using tag-recovery data 



465 



Gleesons Sanctuary and surrounding blocks 



| | Yorke Peninsula and outlying blocks 



'-,- | Gleesons Landing Lobster Sanctuary 

 I | Block 33 



1 Block 40 



Yotke Peninsula 





40 



39 



35 S 



Figure 1 



Location of Gleesons Landing Lobster Sanctuary (small dark area on the bound- 

 ary of MFA blocks 33 and 40) along the west coast of the Yorke Peninsula in 

 South Australia. 



As part of this tagging program (Table 1), 3235 south- 

 ern rock lobsters ijasus edwardsii) were tagged and 

 released into the "fished zone" surrounding Gleesons 

 Sanctuary, namely into statistical reporting blocks 33 

 and 40 (Fig. 1). In January 1994, 413 lobsters were cap- 

 tured, tagged, and released inside the Gleesons Sanctu- 

 ary. These lobsters were predominantly in the range of 

 80-120 mm carapace length (CL), around the size of 

 maturity of about 100 mm CL; more lobsters below the 

 legal minimum length (98.5 mm CL) were released in 

 the fished zone. 



Gleesons Landing Lobster Sanctuary (Fig. 1) is an 

 area where lobster fishing has been prohibited since 

 1982. It lies along the Yorke Peninsula's western coast 

 in an area of medium to low lobster catches. In width, 

 this sanctuary extends 1-2 km from shore to seaward 

 and runs 7-8 km north-south. 



Nearly all tag recoveries were reported by commercial 

 lobster fishermen who noticed tagged lobsters in their 

 catch in the course of day-to-day fishing operations. Tag 

 recoveries of lobsters released into both the sanctuary 

 and the fished zone were, therefore, only possible from 



the fished zone. GPS coordinates, date, and carapace 

 length were recorded for all tagged and recaptured 

 lobsters. Longer-range movements from both sanctu- 

 ary and fished zone were directed southwest towards 

 the shelf edge. 



Prescott et al. 2 previously described qualitative fea- 

 tures of the movement of South Australian Jasus ed- 

 wardsii: 1) nearly all longer-distance movements were 

 directed offshore to deeper water and away from the 

 coast; 2) in order of greater to lesser average distances 

 moved, were i) immature females, ii) males, and iii) 

 mature or egg-bearing females, for nearly all five South 

 Australian regions analyzed; 3 1 movements were largely 

 restricted to lobsters in a specific length range at time 



2 Prescott, J., R. McGarvey, G. Ferguson, and M. Lorkin. 

 1998. Population dynamics of the southern rock in South 

 Australian waters. Fisheries Research and Development 

 Corporation of Australia Report 93/086, p. 23-27. Aquatic 

 Sciences, South Australian Research and Development Insti- 

 tute (SARDI), P.O. Box 120, Henley Beach, South Australia 

 5022, Australia. 



