The larval stages of the southern rock lobster are relatively long, ranging between 12 and 20 months from hatching of eggs to settlement of pueruli.  The planktonic larvae or phyllosomas are dispersed by ocean currents; however, this process is not well understood in southern Australia.  Phyllosomas metamorphose into pueruli larvae which settle on inshore reefs.  The study of settlement of pueruli is being conducted in all southern Australian states.  

Little is known about the relationships between larval settlement, juvenile abundance and adult abundance for Jasus edwardsii in Australia; however, such relationships have been determined for the western rock lobster (Panulirus cygnus) and used to predict catches four years in advance.

The present study aimed to establish larval and juvenile monitoring at three sites in central Victoria, Flinders, Ocean Grove and Torquay.  Larval collection sites were set up and monitored monthly.  Twice yearly, commercial fishers set pots (including fine-meshed research pots) in reef areas near the settlement sites to monitor juvenile and adult abundance.  Extensive tagging was carried out during this fishing and movement of subsequent recaptures analysed.

 

Settlement of larvae was very low at all sites and showed no pattern.  The study sites appear to be in a very low settlement area compared with results from other work to the southwest at Apollo Bay.  

Juvenile and adult abundance was monitored at each site although some practical problems were experienced in fishing near the Flinders site.  There was a lack of animals below 60 mm carapace length in the catches and further work needs to be undertaken to enable sampling of these early benthic stages.

Tagging showed that overall movement was localised with some movement occurring from inshore reefs to deeper water.  A low level of movement was observed but a small proportion of immature females and one male undertook large migrations in a south-westerly direction towards King Island.