Rock lobster stocks off the east coast of Tasmania are in a depleted state and as a consequence a stock rebuilding strategy has been implemented. This has involved adopting a 200 tonnes east coast catch limit, comprising a catch cap for the commercial sector and a notional catch share for the recreational sector. While the commercial catch limit can be monitored and controlled directly, management of the recreational catch share is more problematic.
The recreational rock lobster fishery has been monitored for two decades, during which time there have been significant management changes and variability in stock abundance. The greatest changes have occurred in the east coast, which has traditionally attracted 60-70% of the state-wide recreational catch and effort. In an effort to restrict catches from that region there have been drastic reductions in bag and possession limits and a progressive reduction in season. Furthermore, major biotoxin events have resulted in closures of key areas during peak fishing periods.
High and varying levels of participation has made management of the recreational component of the fishery difficult. This situation is likely to be further exacerbated as stocks rebuild; higher catch rates are expected to attract increased effort and overall catches for the sector. For the commercial sector, the catch cap effectively represents a competitive or “Olympic” catch quota which, as catch rates improve, is likely to influence fleet dynamics and timing of catches as fishers ‘race’ to take the limited catch.
Understanding relationships between fisher behaviour, their expectations/aspirations, responses to changes in stock status and to management intervention is critical when implementing effective management strategies. This project aims to inform on the practical challenges to achieving the stock rebuilding objective and provide options to assist managers and both fishing sectors in achieving the ecological, social and economic goals for the fishery.
For the commercial sector, the east coast catch has been significantly and effectively reduced by capping the quota that can be taken from the region. This has also involved some redistribution of effort into other regions of the state, thereby reducing the negative economic impact of this spatial management measure. Fishers acknowledge, however, that as stocks rebuild competition amongst commercial operators is expected to increase the race-to-fish. Although not a major concern for the sector, those operators with greater dependency on the east coast may experience increasing economic hardship, with the catch cap being reached earlier in the fishing season.
Recreational management settings have not, however, been effective in limiting the recreational harvest to the sector’s allocated catch share. Recreational participation and effort are strongly linked to fishing success, such that as catch rates improve (with stock rebuilding) recreational effort and harvest are predicted to grow, indicating a need for additional management intervention if stock rebuilding catch targets are to be met. The primary challenge in achieving the east coast stock rebuilding objectives is, therefore, the management of the recreational component of the fishery.
Surveys of recreational fishers indicated strong opposition towards any further reduction in daily bag limit (currently two lobster), with low perceived effectiveness and support for the measure as well as confirmation that any reduction would significantly impact fishers’ utility. Such a response was anticipated as rock lobster is a highly consumptive harvest-oriented fishery. A reduction in season length was another management setting that was found to significantly impact most fishers’ utility. In contrast, we found heterogeneous preferences amongst fisher groups (fishing mode and avidity) for an introduced maximum seasonal catch and an increase in minimum size limits. These results may reflect the fact that these measures limit catch indirectly whereas a reduction in bag limit and shortened season have direct and clear implications on expected catch and recreation time. While there was majority in principle support for an individual maximum seasonal catch limit, the limit that would be acceptable to most (median of 20 lobsters) was significantly greater than the average individual catch required to meet the east coast recreational catch share target.
As a direct consequence of the rebuilding strategy catch rates for commercial and recreational sectors are expected to increase substantially, although for the recreational sector the catch rate increase will become increasingly constrained by the bag limit. For the commercial sector this will result in earlier and earlier closures due to the catch cap being reached; the east coast fishery is likely to become a predominantly an early season (autumn) and winter fishery. For the recreational sector and in the absence of additional management restrictions, the combined effects of higher catch rates and participation are predicted to lead to an increase in the east coast catch of between 57 and 125% above 2018/19 levels by 2023. Increases to this level will undermine the stock rebuilding strategy and prevent the stock rebuilding target being achieved in at least one of the east coast stock assessment areas.
Model projections suggest that to maintain catches within the recreational catch share allocation will require a reduction of effort to half of the 2018/19 level by 2023. To achieve this with existing input controls will be a formidable challenge, especially in the context of anticipated increased participation arising from increasing catch rates.
The alternative of maintaining the total East Coast catch at the target levels by off-setting recreational over-catch against the commercial catch share would lead to increased fishing pressure in other areas of the state. Without additional management changes this redistribution of catch is predicted to prevent achieving rebuilding targets in some stock assessment areas outside of the east coast. Consequently, management changes such as a reduction in the total allowable commercial catch allocation or further spatial management to support rebuilding in impacted areas may need to be considered.
Although direct management recommendations are beyond the scope of the current study there are several observations that are expected to assist in future decision making. In relation to existing management settings, season length is likely to be the most effective in constraining catches although it is clear that progressive and significant reductions would be required to achieve the recreational catch share target. Minor adjustments, as implemented in the past have not been sufficient in this regard.
In relation to alternative management options, the concept of a maximum individual seasonal catch limit has merit, not the least in that it ensures a more equitable distribution of the catch between fishers. However, without limits on the number of recreational licences issued each year such a system cannot directly control the total catch. Catch or harvest tags represent a practical means to implement such a measure but there are risks and costs associated with implementation and administration of a such as system that require careful consideration.
In-season catch monitoring, whether based on reported tag usage, mandatory reporting or survey methods, could be applied in much the same way as the commercial catch cap is managed, i.e. the season is closed when the catch limit is reached.
It may also be reasonable to review the east coast catch share split between commercial and recreational fisheries as an element of future management direction. However, in the absence of policy guidance around fisheries allocation (or reallocation) in Tasmania any such determination would ultimately be a political decision. A re-allocation of a higher proportion of the catch share to the recreational fishery would ease the regulatory burden on the sector but would still need to ensure that recreational catches are effectively monitored and constrained within the revised catch share arrangements.
Although there may be no simple solutions to the management of this shared fishery it is hoped that the current project will assist resource managers, recreational and commercial sectors in working proactively to meet the challenges.