5.4 GOVERNANCE
5.4.1 Department of Fisheries – Management
5.4.1.1 Management effectiveness (outcomes)
Rationale for inclusion
The effectiveness of management activities (e.g. spatial and temporal closures, limited entry, gear controls) should ultimately be reflected by the extent to which the fishery continues to produce expected outcomes (maintaining the catch of prawns at acceptable levels). In Sections 5.1.1.1 – 5.1.1.4, the catches for the individual prawn species were discussed and analysed, therefore this section will look at the cumulative catch and assess whether current management arrangements are maintaining the total catch for all prawn species within an acceptable range. Thus, if the annual acceptable catch range of prawns is maintained then the community’s expectation that variations in annual catch result only from annual changes in environmental conditions, or planned changes to the management of the level of commercial exploitation and not from stock depletion will be continued. Any large unexplained variation in catch, particularly any significant and unexplainable reduction in catch, is likely to be a reflection of a reduction in the management effectiveness. This would reduce the community’s confidence in the management of the resource and raise concerns about the ongoing sustainability of the fishery.
Operational objective
The commercial catch of all prawns is maintained within an acceptable range on an annual basis.
Justification
If all management arrangements developed for this fishery, including the restrictions on effective effort levels, compliance with the regulations is being maintained effectively, combined with our understanding of the size of the exploitable stock - then the total catch (for king, tiger, endeavour and banana prawns) should be within the historical acceptable range. Any variation outside this range would elicit the need to at least explain the cause of this deviation.
ESD Report Series No. 1 – Exmouth Gulf Prawn Fishery
Indicator
The total catch compared to historical acceptable range for all four penaeid prawns in the EGP fishery.
Performance measure
Under current fishing effort levels, the catch projections for this fishery are that the total catch of penaeids should be within the range of 771-1,276 t.
Justification
The justification for the individual levels for each penaeid species is located in Section .1.
Data requirements for indicator
The following data is required for this indicator:
Data Requirement Data Availability
Commercial catch and effort. Yes – obtained annually.
Historical catch levels. Yes – records available and accessible.
Level of fishing effort and fishing power. Yes – number of vessels, days fished, hours trawled, areas of operation and activity and fishing power comparisons readily available.
Environmental indicators. Yes – key environmental indicators readily available.
Evaluation
Summary: Historical catch and effort information indicate that production levels for this fishery have been relatively stable over the past 5 years. The catch has generally been within the agreed reference range. Therefore, the performance measure has not been triggered and current management strategies appear to be effective in achieving the overall objectives for the fishery.
The total catch of penaeids by the EGP fishery was 1,467 t in 1999, which is just above the acceptable catch range (Table 7). The higher catch was a result of an unusually large catch of endeavour prawns in this year, which was caused by the unusual and strong impacts of Cyclone Vance on the Exmouth Gulf region. This was reflected in the 2000 catch, which was down with 565 tonnes of prawns caught in total.
This was below the acceptable catch range due to the negative impacts of Cyclone Vance.
Table 5. The total catch of penaeids in the EGP fishery.
Year Total Catch of Penaeids (t)
1990 1,149
1991 958
1992 1,036
1993 1,020
1994 1,276
1995 1192
1996 771
1997 815
1998 1,058
1999 1,467
2000 565
Robustness
Medium/HighThe data required for the indicator is, in most cases, readily available. The changes in fishing power and fleet efficiency through time need to be evaluated and considered in these analyses to ensure that the measures continue to be relevant.
Fisheries management response
Current: The management measures imposed to achieve the objective for the spawning stock and total catch (see above) also serve to achieve the objective related to the exploitable stock.
Historically, variations in catch outside of the range expected have been explained either in terms of increased fishing effort, increased fishing efficiency or seasonal environmental factors. The response to this has been to reduce fishing effort (e.g. spatial or temporal closures) or to develop the predictive model to take account of environmental factors such as sea surface temperature and ENSO and El Ninó events.
Future: The Department of Fisheries is doing further work to both improve the measurement of fishing efficiency and understanding the relationship between environmental factors and catch. The Department of Fisheries will continue to use input controls to adjust for variations in fishing efficiency.
Actions if Performance Limit is Exceeded: If the catch is outside of the range of expected values then a review of the causes would be undertaken prior to the beginning of the next season. This review would examine why the acceptable catch range was not met. If this variation is not explained by effort reductions or abnormal environmental variations then strategies that offer further protection to the breeding stock will be implemented for the following season. These strategies could include:
• Further reductions in the total effort expended in the fishery through a reduction in the length of the fishing season or within season closures, and/or extension of moon closures.
• Additional area closures.
• These actions can be initiated within a season or prior to the beginning of the next season.
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ESD Report Series No. 1 – Exmouth Gulf Prawn Fishery
Comments and action
While the Department has been able to maintain the catch of tiger, king, coral and endeavour prawns within acceptable levels, it continues to work on improving and refining the methods used to determine breeding stock estimates. The use of GIS systems for analysing data has commenced.
External driver checklist
Environmental factors such as: climatic changes, cyclonic activity impacting habitat, ocean currents and sea-surface temperatures are known to impact upon recruitment and therefore are likely to impact the catch of prawns. In Exmouth Gulf, the most significant risk factors are cyclonic activity and significant environmental pollution or habitat degradation.