Western Australia's fishery for western rock lobster (Panulirus cygnus) has received international acknowledgement as one of the best managed and most sustainable in the world. Several protective measures are used to ensure the sustainability of WA's rock lobster populations including a management plan, rules and licences for both commercial and recreational fishers, a seasonal closure, size limits, protection for any females in breeding condition and controls on the number of pots and on the gear used (such as pot size limits).
An extensive scientific program supports the management of the western rock lobster fishery. The program not only collects data on commercial and recreational catches and fishing activity, but also includes a number of independent monitoring programs that look at the abundance of the lobster breeding stock, the settlement from year-to-year of juvenile lobsters, and environmental factors that may affect breeding success and survival. This research allows fisheries scientists to predict catches up to four years in advance.
A key to predicting catches is the annual sampling program, which looks at the abundance of late larval stage lobsters (pueruli) settling on inshore reefs along the west coast between August and January each year.
Past research has shown, in years when the Leeuwin Current is strong (associated with La Nina events), levels of puerulus settlement have been high, resulting in high catch rates three to four years later. In years when the Leeuwin Current is weak (El Nino events), associated catches are usually lower.
The western rock lobster fishery faces a number of challenges over the coming years to ensure sustainability.
Puerulus settlement during 2008/09 was at record lows levels at nearly all sampling sites. This low settlement has been particularly unusual because it occurred during a year that the Leeuwin Current was strong, which means other environmental factors and/or breeding stock issues may be contributing to this decline.
In Shake, Settle & Roll, students will learn about the biology of the western rock lobster and the environmental factors that influence the fishery. Students will have a close encounter with a western rock lobster, view footage of Fisheries research staff carrying out field work, then simulate this themselves by shaking out puerulus from collector sheets and using this data to estimate the future lobster catch.
This activity addresses outcomes in both Biology and Geography courses of study.
Further resources applicable to this activity are available here.
