Project number: 2008-900
Project Status:
Completed
Budget expenditure: $92,276.57
Principal Investigator: Dexter Davies
Organisation: Western Rock Lobster Council Inc (WRLC)
Project start/end date: 14 Nov 2008 - 14 Nov 2009
Contact:
FRDC

Need

For the WRL fishery, this situation has resulted primarily from a relatively static beach price for lobster and increasing fuel, labour and other input costs. A major driver for input costs in this fishery is the number of pot lifts, which is currently about 10 million annually, equating to a total cost of ~$60 million (average cost per potlift - $6.00). If a lobster trap could be introduced into this fishery with a volume approx twice that of traditional pots, thereby enabling fishers to capitalise on the gregarious nature of the animal whilst preventing escapees, the fishing behaviour of the fleet would adapt accordingly to focus on primarily extended soaks i.e. 48 and 72 hours. It is envisaged that the cost savings associated with this shift in fishing behaviour would translate to a more economically viable fleet.

The introduction of a lobster trap which causes a reduction in the number of pot lifts has the potential to enhance the primary measure of exploitation in the WRLF namely, catch per unit effort (CPUE). A 10-20% reduction in pot lifts over an entire season would result in cost savings to the tune of $6-12 million annually. This project aims to trial a lobster trap which will encourage fishers to alter their fishing behaviour thereby increasing their CPUE which translates directly to cost savings in fuel and bait usage.

The decision to use more efficient pots could be undertaken at an individual fisher level, but this requires robust conversion rates for any modified design(s) to ensure that the integrity of the fishery's input based management system is not compromised. The potential for further cost savings arising through the purchase and maintenance of licences containing lesser numbers of entitlements is also likely.

Objectives

1. To calculate the potential cost savings which arise through the use of a reduced number of more efficient 1.2m lobster traps in tandem with a modified fishing behaviour. These estimates would be derived by obtaining attaining robust estimates of catch rates (catch per unit effort) using the 1.2m trap compared to traditional pots in the fishery combined with the estimated reduction in operating costs that would arise from the widespread adoption of the 1.2m traps. For instance, a fisherman choosing to deploy a 1.2m trap that is 20% more efficient than traditional methods would lose 20% of his entitlements. This analysis would incorporate both varying estimates of efficiency and degree of uptake by industry.
2. To determine whether a modified 1.2m lobster trap will alter the fishing behaviour of the WRL fleet which is traditionally focused on 24 hour soak times. This would be achieved through an increased reliance on a trap which is greater in volume than the traditional pot, retains 100% of animals and ideally suited to extended soak times i.e. 48 – 72 hours.

Final report

ISBN: 978-0-9807845-9-6
Authors: Andrew Winzer Roy Melville-Smith Simon de Lestang & Adrian Thomson
Final Report • 2011-03-01 • 961.56 KB
2008-900-DLD.pdf

Summary

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.

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