2008/900 Improving profitability in the Western Rocklobster fishery using a new rocklobster trap

By Andrew Winzer et al

This project investigated the efficiency of using different pot designs to increase the profitability of the Western Rocklobster fishery. The motivation for this study was a more efficient pot would reduce the number of pot hauls, and that this in turn would increase profitability of the fishery by reducing the amount of bait used, the amount of time at sea, fuel usage and overall wear and tear on equipment.

During the course of this project, three different pot designs were trialed against the standard batten pot design. Trials of the new pot designs were undertaken in more than one management zone and for one (and more than one) day soaking times. In nearly all instances, standard batten pots proved to be more successful in catching lobsters than the two of the trialed pot designs. However, the third design, a side entrance batten pot with a broad base, hereafter termed the 'broad based pot', proved to be more effective than standard pots under particular conditions. In trials conducted during the reds part of the 2008/09 season, catches of legal sized lobsters made by broad based pots were not significantly different to those made by standard pots for one day and greater than one day soaking times. However, the broad based pots tended to catch fewer undersized lobsters. Trials of the broad based pots during the early part of the 2009/10 whites season showed that while they were not significantly different in terms of their ability over standard pots to catch legal sized lobsters on one day soaking periods, they were superior to the standard pot on two day soaks. The broad based pot design also caught significantly fewer under sized lobsters over two day soaking periods.

These results suggest that the use of broad based pots during the whites fishing season combined with longer pot soaking times would be expected to lead to multi-million dollar cost savings through reduced pot lifts. Furthermore, there would be a substantial reduction in the handling of hundreds of thousands of sub-legal discarded lobsters which could be expected to have beneficial flow-on effects in terms of future catch.