PAUA (PAU 5A)

Figure 1: Location of boundaries of the paua (PAU) quota management areas (QMAs) for PAU 5A, PAU 5B, and PAU 5D

Executive Summary

1. In 1995, PAU 5 was separated into three stocks: PAU 5A, Fiordland; PAU 5B, Stewart Island; and PAU 5D, Otago. The total allowable commercial catch (TACC) was divided equally among the new stocks. The existing TACC for PAU 5A, therefore, is not based on a stock assessment. Formation of these stocks led to a large redistribution of catch from Stewart Island to Fiordland and the Catlins/Otago coast. Recent catches in PAU 5A appear to be consistently higher than in the past, with the larger proportion of commercial catch occurring in the southern zones.
   
2. A new stock assessment shows there is a serious sustainability concern with PAU 5A. The assessment indicates that the current TACC and recent catches may not be sustainable. There is uncertainty over applying the assessment projections to the whole of the PAU 5A stock.
   
3. MFish considers there is sufficient certainty in the assessment to show that PAU 5A is not rebuilding and moving towards the B _MSY. The Shellfish Fishery Assessment Plenary, May 2006 (the Plenary) agreed that current catches will result in further depletion within the southern zones ¹ of PAU 5A. MFish considers that a TAC needs to be set and the TACC reduced to lower the risk of further depletion to the stock.
   
4. A total allowable catch (TAC) could be set for a faster rate of rebuild, based on the stock assessment projections for the whole of the PAU 5A stock. However, the uncertainty associated with the assessment, as highlighted in the Plenary report, does not commend this course of action.
   
5. An alternative option is to reduce the catch by applying the stock assessment projections on a proportionate basis to the south zone only. This option would result in a TAC of 94 tonnes and a slower rate of rebuild. It is assumed that the southern zones contain a larger proportion of the PAU 5A biomass. This is considered to be a reasonable assumption as southern zones are less precipitous, and have more complex waterways, providing more paua habitat than the northern zones. A large proportion of the catch has been taken from the southern zones.
   
6. This option has some risk to sustainability, as it is not known whether current catches in northern zones are sustainable. This risk can be mitigated by undertaking research and another stock assessment at an earlier date than is currently scheduled.
   
7. Alternatively, if the Minister considers there is sufficient uncertainty in the stock assessment for the PAU 5A stock, he could consider other options. The Minister could decide to retain the TACC at its current level of 148.98 tonnes. MFish considers that, based on the best available information, the stock is below the B_MSY and there is a high risk of stock decline at current catches. Therefore, MFish believes a TAC should be set that reduces the total removals from this stock.
   
8. The Minister could also consider an industry proposal to cut their catch in the southern zones by 45 tonnes. Industry prefers to effect this catch reduction by shelving of ACE or, alternatively, reducing the TACC by a minimum amount and shelving the remainder. M Fish does not consider that the industry proposal, with a 45 tonne catch reduction, meets the Minister’s obligations under s 13(2)(b) to set a TAC that moves the stock towards being at or above the B_MSY.
   
9. The allowances for customary, recreational, and other sources of fishing-related mortality are being set for the first time. The catches by these sectors are considered to be very small in relation to the commercial harvest in PAU 5A. MFish proposes setting small allowances to cover current catches.
   
10. MFish’s preferred option is reducing the catch by applying the stock assessment projections on a proportionate basis to reduce the catches in the southern zones, as an interim measure, until further research and another stock assessment is completed.
    

Summary of Options

11. MFish considers that the PAU 5A stock is below B MSY. Two options are proposed to set and review the TAC, T ACC, and allowances for PAU 5A:
• Option one - Set a TAC ² of 57 tonnes and reduce the TACC from 148.98 to 47 tonnes to achieve a high probability of rebuild.
• Option two - Set a TAC of 94 tonnes and reduce the TACC from 148.98 to 84 tonnes to achieve a slower rate of rebuild. achieving a catch reduction in the southern zones.This option is based on achieving a catch reduction in the southern zones.
  
12. Alternatively, if the Minister considers there is sufficient uncertainty in the stock assessment for the PAU 5A stock he could consider the following options:
• Option three - Status quo, maintain the existing TACC of 148.98 tonnes.
• Option four - Industry has put forward a proposal to reduce the commercial catch by 45 tonnes (equivalent to reducing the TACC to 104 tonnes) in the southern zones. Industry proposes to achieve this preferably by (a) shelving ACE which will not be fished or, if the Minister is obliged to make a TACC reduction, by (b) reducing the current TACC by a minimum and shelving the remainder of the 45 tonnes as ACE. Industry proposes to support this catch reduction with other voluntary initiatives.
  
13. It is not proposed to review the generic regulatory restrictions that apply to minimum legal size (MLS), daily bag limits, or the use of underwater breathing apparatus at this time.
    

Rationale for Management Options

Formation of PAU 5A

14. In 1995, PAU 5 was separated into three stocks: PAU 5A, Fiordland; PAU 5B, Stewart Island; and PAU 5D, Otago. The TACC was divided equally among the new stocks, and the TACC for PAU 5A was set at 148.98 tonnes under the Fisheries Act 1983. It is widely considered that this led to a large redistribution of catch from Stewart Island to Fiordland and the Catlins/Otago coast. Recent catches appear to be consistently higher than in the past (see Appendix 2, Figure 3). But the exact increase in catch in the new PAU 5A cannot be determined with certainty because one general statistical area used to report catch and effort straddled the three new stocks.
    
15. The existing TACC for PAU 5A is not based on a stock assessment.
    
16. Both the other fishstocks created in this subdivision have subsequently had their TAC/TACCs reduced; PAU 5B TACC from 149 to 90 tonnes, PAU 5D TACC from 149 to 89 tonnes.
    

Northern and southern zones

17. The northern and southern zones of PAU 5A have had different fishing pressure on them. The bulk of the commercial fishing has occurred in the southern zones - these zones have provided 64% of the catch over 2001-2005 (see Appendix 2, Table 3).
    
18. There are marked differences between northern and southern fiords. The topography of the southern fiords (Dusky Sound, Chalky and Preservation Inlets) and the south coast zone is less precipitous and is more open, shallower, with many islands and stacks scattered throughout complex waterways³.The open coast kelp-based communities penetrate further into these southern fiords than in northern fiords. MFish considers that the southern zones provide more paua habitat than the northern zones and, therefore, are highly likely to support a greater biomass. Information from fishers and the way the fishery has developed also suggest that the southern zones do contain more suitable paua habitat.

Stock assessment

19. A new stock assessment for PAU 5A estimates that current spawning biomass ⁴ has a median value of 482 tonnes (5% to 95% range 382-619 tonnes) and the median is projected to decline to 294 tonnes (59% of its 2005 level) in the next three years (by 2008) at current catch (see Appendix 2, Tables 4 and 5). The probability that this decrease in spawning biomass will occur is estimated to be 89% if current total catch levels continue.
    
20. The assessment also estimates that, within this current spawning biomass, there is a median 276 tonnes (5% to 95% range 218-355 tonnes) of recruited biomass⁵.Therecruited biomass is projected to decline to 35% of its 2005 level in the next three years with 100% probability of this occurring. At this level of predicted exploitation, MFish considers commercial fishers will not be able to take the TACC after three years and that commercial fishing will shift, as depletion occurs, from the southern zones to the northern zones.
    
21. The current (2005) exploitation rate⁶ is estimated at 45%. At current catch levels, the exploitation rate in the commercial fishery is predicted to increase to at least 65% in the next three to five years. While there are no documented “safe” exploitation rates for paua fisheries, MFish considers there is considerable risk in managing a paua stock under a high exploitation rate because the recruited fishery relies on recruitment success of pre-recruits. Such stocks would be expected to decline if recruitment failed.
    
22. Under high levels of exploitation, the fishable biomass would continue to rely strongly on paua recruiting across the 125mm MLS into the fishery. In reality, the stock between 97mm and 125mm are the “safety net”. The low frequency of pre-recruits in paua populations suggests that the productivity of paua stocks is low, and this is particularly true for Fiordland.
    
23. It has been reported ⁷ that there is low recruitment in Fiordland because the exposed nature of the coast prevents settlement and survival of young paua. It is likely that nursery areas, such as inside the sounds, could be supplying recruits to more exposed locations where adults tend to be found in greater numbers. Nevertheless, the exposed nature of the area will lead to low replacement.
    
24. The assessment notes that the model projections are also likely to be optimistic due to local effects, such as recruitment failure. The assessment model treats the whole of PAU 5A as if it were a single biological stock. The extreme weather typical of parts of the Fiordland coast make it probable that fishing pressure is concentrated in sections of coast, causing a large difference in exploitation rates and serial depletion within the QMA. Serial depletion can lead to recruitment failure because spawners must breed close to each other, and because the dispersal of larvae may be limited. Recruitment failure is a common observation in paua fisheries, internationally.
    
25. In the stock assessment, the research diver survey index (RDSI) and catch-per-unit-effort (CPUE) data gave conflicting results. The Plenary accepted the use of RDSI as being more reliable for stock assessment because CPUE data is known to be an unreliable index of abundance in paua fisheries.
    
26. The assessment results suggest that the current TACC and recent catches are not sustainable. The assessment assumes that the RDSI indexes biomass in the whole of PAU 5A – “This requires that the average decline in biomass in the surveyed southern zones is consistent with the average trend in biomass in the remainder of PAU 5A, or that the southern zone contains most of the PAU 5A biomass. A large proportion of the catch has been taken from the southern zones, but this does not imply that it contains (or contained) most of the PAU 5A biomass”. These were possible factors affecting the stock assessment. However, the typography of Fiordland, information from fishers, and the way the fishery has developed suggest that southern zones do contain more suitable paua habitat and, therefore, biomass than northern zones.
    
27. The assessment, therefore, is dependent on the RDSI adequately indexing the biomass in the whole of PAU 5A. But this may not be the case, as there has only been one RDSI survey in the northern zones (in George zone only in 2006) whereas there has been more comprehensive coverage in the southern zones (in South Coast and Chalky zones in 1996; in South Coast, Chalky, and Dusky zones in 2002 and 2006).
    
28. As a result, the Plenary could not agree on applying the assessment projections to the whole of the PAU 5A stock. The Plenary agreed that current catches within the southern zones of PAU 5A will result in further depletion within that area.
    

PAU 5A stock is below B_MSY

29. The RDSI shows that the decline in biomass in the southern zones for 2002-2006 (years in which the three southern strata were all surveyed) ranged between 50-78%,with 90% confidence (Appendix 2, Table 6). Therefore, the recent decline is statistically significant and substantial.
    
30. The Plenary agreed that current catches will result in further depletion within southern zones.
    
31. Southern zones have contributed the bulk of the catch from PAU 5A. If current catches are allowed to continue, southern zones will become further depleted, and fishing effort will progressively transfer to the northern zones. It is highly unlikely that the northern zones provide sufficient paua habitat to support the level of catch that has been extracted from the southern zones. Therefore, MFish concludes that this paua stock will continue to decline at current catch levels. It is possible that the TACC has not been sustainable from early in its history.
    
32. MFish notes that the Plenary did not reject the assessment, but they could not agree on whether it applied to the whole of PAU 5A.
    
33. Despite the Plenary reservations about the stock assessment projections applying to the whole of PAU 5A, MFish considers that, based on the best available evidence, the stock is below B_MSY and there is a high risk of further decline in the stock at current catches.
    
34. There is an obligation under the Fisheries Act 1996 (the Act) to utilise fisheries resources while ensuring sustainability (s 8). The main tool available to ensure the sustainable utilisation of QMS stocks is the establishment of a TAC under s 13 of the Act. Where a stock is below the B_MSY, the Minister has an obligation under s 13(2)(b)to set a TAC that moves the stock towards being at or above the B_MSY.
    

Rebuild strategy

35. As part of setting a TAC for the PAU 5A stock, a rebuild strategy needs to be adopted. In determining the way and rate of rebuild the Minister has some discretion. The rebuild may be made faster or slower having regard to biological characteristics and environmental factors that affect stock size, and having regard to social, cultural and economic factors. Section 13(3) makes it explicit that social, cultural and economic factors are relevant in determination of the way and rate of progress to the B_MSY, rather than determination of the level of the B_MSY.
    

Assessment of Management Options

36. There is uncertainty with the stock assessment for PAU 5A. The majority of assessment information has been gathered from the southern zones and, therefore, there is some uncertainty about whether the observed decline in biomass applies to the northern zones. As a result, it is not known precisely where the PAU 5A stock is in relation to the B _MSY, or what the sustainable yield from the stock is. But MFish considers that, based on the best available information, the stock is below the B_MSY and there is a high risk of stock decline at current catches.
    
37. Based on the premise that the PAU 5A stock is below B MSY, two options are considered to set and review the TAC for PAU 5A (options one and two). Alternatively, if the Minister considers there is sufficient uncertainty in the stock assessment for the PAU 5A stock, he could consider other options (options three and four).
    

Option one - Set a TAC and reduce the total removals to achieve a faster rebuild rate

38. Under option one, the Minister sets a TAC of 57 tonnes and reduces the total removals to provide a faster rate of rebuilding the spawning biomass.
    
39. As noted in the Rationale, the RDSI shows that there has been a statistically significant decline in biomass in the southern zones between 2002 and 2006. The assessment for PAU 5A predicts there will be a continuing decline in the stock biomass over the next three to five years (by 2010) at current catches. At this level of exploitation, the model predicts that commercial fishers will not be able to take the TACC after three years.
    
40. The stock assessment also projected exploitation rates and biomass at annual catch levels of 157, 127, 97, 67, 57, 47, and 37 tonnes (see Appendix 2, Tables 7 and 8). At a catch level of 57 tonnes, the exploitation rate is estimated to decrease from 45% in 2005 to 19% in 2008, and to 16% in 2010. The spawning biomass is predicted to have a 61% probability of increasing to a median value of 534 tonnes (range 344-993 tonnes) in 2008, and an 81% probability of increasing to 659 tonnes (365-1290 tonnes) in 2010.
    
41. At catch levels above 57 tonnes, the projected exploitation rates and biomass offer much higher exploitation rates and little prospect of biomass recovery (see Appendix 2, Tables 7 and 8).
    
42. In his consideration of this option, with uncertain information, the Minister could take a precautionary approach and make a decision that has the lowest risk to sustainability. The Minister will need to be satisfied that there is sufficient certainty in the stock assessment, despite the Plenary reservations about the projections applying to the whole of PAU 5A, that indicates that the whole of the PAU 5A stock is below the B_MSY. He could then take a precautionary approach and set the TAC at 57 tonnes.
    
43. This option has the lowest sustainability risk. On the other hand, this option has the highest economic cost in annual lost earnings if the port price does not change with the TAC/TACC reduction. There will be social and economic consequences from a reduction to the TACC. If the supposition that the biomass decline does not apply to the northern zones proves correct, then this TACC cut will be too severe and some of the lost earnings and social costs will not have been necessary.
    
44. This option could have a negative impact on compliance with the voluntary 127mm MLS, reseeding, and the future development of a fisheries plan for the PAU 5A fishery. Balanced against this is that non-commercial interests will be least impacted under this option, with the substantial TACC reduction reducing the risk of paua not being available to non-commercial fishers.
    
45. MFish considers that the uncertainty associated with the assessment, as highlighted in the Plenary report, does not commend implementing this option.
    

Allowances for customary, recreational interests and other sources of fishing-related mortality

46. The stock assessment model assumes that the recreational catch was 1 tonne in 1974, increasing to 2 tonnes in 2005, that customary catch was 1 tonne throughout, and that illegal catches have been 5 tonnes throughout the assessment period. The Plenary agreed to not make any allowance for handling mortality in the stock assessment model (see Appendix 2, paragraph 124). The model only included catches taken within the commercially fished area, but it is considered that only negligible noncommercial catches of paua will come from other areas in Fiordland.
    
47. The limited information available indicates there are only low levels of noncommercial catch. The most recent National Recreational Fishing Survey in 2000 -01 estimated a 2.8 tonne recreational harvest, and the Tangata Tiaki/Kaitiaki customary fishing authorisations show that less than one tonne has been taken in any year (see Appendix 2, paragraphs 115-118).
    
48. There is no information available on the amount of fishing-related mortality from either illegal fishing or damage from handling of sub-legal paua (see Appendix 2,paragraphs 119-120). MFish considers that a nominal allowance should be set to include both sources of mortality.
    
49. The allowances for customary and recreational fishing are being set for the first time and, therefore, are not being set as a proportion of the TAC and will be the same for all options. Most of the nominal allowance for other sources of fishing-related mortality is for illegal fishing. The level of illegal fishing is not related to changes in the TAC, therefore, this allowance will also be the same for all options.
    
50. It should be noted that the recreational harvest of paua in Fiordland, since April2005, has been restricted to the daily bag limit of 10 paua with no accumulation permitted over several days of fishing.
    
51. MFish proposes setting small allowances to cover the best estimates of current catches. It is proposed that the allowances for Maori customary harvest be set at 1 tonne, for recreational fishers at 3 tonnes, and an allowance for other sources of fishing-related mortality at 6 tonnes.

TACC

52. This option would result in a reduction in the TACC from 148.98 to 47 tonnes.
    
53. An economically significant commercial fishery has been developed around the PAU 5A fishery. The economic effect of a reduction of the TACC to 47 tonnes is not fully known. It is anticipated the cost of quota and ACE would increase. Any increase in ACE prices is likely to contribute to a reduction in profitability for ACE-dependent fishers.
    
54. This option has the highest economic cost of $3.78 million in annual lost earnings if the port price does not change with the TAC/TACC reduction (see Appendix 2, Table 10).
    
55. There would be social and economic consequences from a reduction to the TACC. The precise extent of these effects has not been quantified. MFish is seeking detailed information from commercial fishers, through their submissions, to supplement analysis MFish is currently undertaking to include in the final advice paper on the economic impact of the proposed options of TAC/ TACC reductions.
    

Option two - Set a TAC and reduce the total removals, with a slower rate of rebuild

56. Under option two, the Minister sets a TAC of 94 tonnes and reduces the total removals for a slower rate of rebuild. Option two is based on achieving a catch reduction in the southern zones of PAU 5A. This option is an interim measure until further research and another stock assessment is completed.
    
57. As noted, while the Plenary did not reject the assessment, there is disagreement about applying the RSDI decline in biomass to the northern part of the stock. The Plenary do agree, however, that current catches are not sustainable in the southern zones. As noted, the RDSI information shows a substantial decline in biomass in the southern zones for 2002 -06. So arguably, at least, the assessment projections apply to the southern zones.
    
58. An alternative option, then, is to reduce the total catch by applying the stock assessment projections on a proportionate basis to the south zone only, while accommodating current catches in northern zones (see Appendix 2, Table 9). This alternative approach will have a lesser rate of rebuild than option one. However, this option has some merit as a large proportion of recent catch (64%) has been taken from the southern zones, and the adverse stock assessment for PAU 5A is largely based on data from the southern zones. Also, as noted, it can reasonably be assumed that the southern zones contain the larger part of the PAU 5A habitat and biomass.
    
59. In his consideration of this option, the Minister will need to be satisfied that there is a reasonable prospect that a lesser reduction in catches for the whole QMA will allow spawning biomass to increase sufficiently to start rebuilding the PAU 5A stock towards the B_MSY.
    
60. The overall probability of this reduction in total removals resulting in the spawning biomass increasing cannot be calculated as the status of the northern zones at current catches is not known.
    
61. For southern zones, total extractions (commercial plus non-commercial) will be about 36 tonnes. The effect of the proposed harvest from the southern zones will be equivalent to a projected 57 tonne catch overall with the probabilities given in Appendix 2, Table 8 for rebuild of the fishery in the southern zones. Current median spawning biomass in southern zones is estimated to be 315 tonnes. Under the proposed rebuild, there is a 61% probability that spawning biomass will be greater in 2008 (at 342 tonnes) than currently, and a 81% probability it will be greater in 2010 (422 tonnes).
    
62. There is a risk with this option as to whether current catches in northern zones are sustainable. Option two assumes that no reduction in catch levels in the northern zones is required. This assumption may or may not be true. The best scenario is that current catches are sustainable, but there is a risk they are unsustainable.
    
63. A smaller proportion (36%) of the catch has come from northern zones. If increased fishing occurs in the northern zones under this rebuild option, it is likely that the paua stocks in northern zones will suffer depletion, but there will be some protection to the spawning biomass from the 125mm MLS. It also follows that southern zones will have less fishing pressure, and the rate of rebuilding will be faster than projected above. Therefore, it is highly unlikely that any depletion of the smaller northern stocks will negate the faster rate of rebuild in the southern zones, at least in the short term, say two to three years.
    
64. On balance, there is no evidence that this slower rate of rebuild in PAU 5A, with the TAC set at 94 tonnes, will not be sustainable.
    
65. The uncertainty in the assessment and the risk of depleted stocks in northern zones can be mitigated by undertaking research and another stock assessment earlier than is currently scheduled, in 2011. Given the uncertainty on applying the RDSI average decline in biomass to all PAU 5A, it is proposed that a new RDSI survey be undertaken followed by a stock assessment in 2007 -08 so that a TAC review can be implemented for 1 October 2008.
    
66. The risk to sustainability is higher with this option than option one, while the social and economic costs are lower.
    
67. The reduction in total removals should reduce the risk of paua not being available to non-commercial fishers.
    

Allowances for customary, recreational interests and other sources of fishing-related mortality

68. The catch by customary, recreational, and illegal fishers is very small and has little impact on paua biomass in PAU 5A, compared to commercial catch. As noted, the allowances for customary and recreational fishing are being set for the first time and, therefore, are not being set as a proportion of the TAC and will be the same for all options.
    
69. Under option two, therefore, MFish proposes setting small allowances to cover the best estimates of current catches.It is proposed that the allowances for Maori customary fishers be set at 1 tonne, for recreational fishers at 3 tonnes, and an allowance for other sources of fishing-related mortality at 6 tonnes.

TACC

70. This option will result in a reduction in the TACC from 148.98 to 84 tonnes.
    
71. The annual lost earnings are estimated at $2.41 million (see Appendix 2, Table 10). The precise extent of the social and economic consequences has not been quantified and MFish is seeking detailed information from commercial fishers, through their submissions, to supplement analysis MFish is currently undertaking on the economic impact of the proposed options of TAC/ TACC reductions.
    
72. This option has greater socio-economic consequences on small boat commercial fishers. With reduced availability of paua in southern zones, some commercial fishers with small boats (for example, those based at Riverton) are likely to have problems in fishing the open, exposed, often turbulent waters in the northern zones.
    
73. It would be desirable for catch spreading arrangements being agreed to and complied with by industry to reduce catch in southern zones and maintain current catch in the northern zones. Without catch spreading, there is a risk of depletion of northern zones. As noted, MFish considers it is unlikely that the northern zones provide sufficient paua habitat and biomass to support the level of catch that has been extracted from the southern zones.
    
74. There is a risk in the Minister relying on voluntary catch-spreading arrangements. These voluntary arrangements undertaken by industry members cannot be statutorily enforced. If the arrangements fail, an option is available to the Minister to review the TAC in subsequent years to ensure rebuild.
    

Option three – Status quo (retaining the existing TACC)

75. Under option three, the TACC will remain unchanged at 149.98 tonnes, and there will be no requirement to set a TAC or allowances.
    
76. For the Minister to support this option, he will need to be satisfied that there is sufficient uncertainty in the stock assessment that it provides no useful information on whether the PAU 5A stock is below, at, or above the B_MSY.
    
77. So what is known about the PAU 5A stock? Commercial catches have been close to the TACC in each year since PAU 5A was formed in 1995, with the TACC nearly being fully taken in recent years (see Appendix 2, Table 2). As noted, the Plenary agreed that current catches within the southern zones of PAU 5A will result in further depletion within that area.
    
78. With no change to the TACC, there is a considerable risk that the bulk of the commercial fishing will shift, as depletion occurs, from the southern zones (that currently provide 64% of the catch) to the northern zones.
    
79. As noted, MFish considers it is unlikely that the northern zones provide sufficient paua biomass to support the level of catch that has been extracted from the southern zones.
    
80. There is some uncertainty in the assessment projections applying to the whole of PAU 5A. But, MFish considers there is sufficient certainty that, based on the best available information, the PAU 5A stock is below B MSY, and it is not rebuilding and moving towards the B_MSY. Therefore, MFish considers the TACC should be reduced to lower the risk of further depletion of the stock in southern zones, followed by serial depletion in the northern zones. At current catches there is a risk of collapse of the fishery over the next few years.
    
81. In the short term, there will be little or no economic cost from not reducing the TACC (see Appendix 2, Table 10). But in the medium to longer term there will be social and economic costs from a probable collapse of the PAU 5A stock, with commercial fishers being unable to catch the existing TACC and non-commercial fishers having increasing problems catching paua.
    

Option four - Industry proposal

82. Industry proposes to reduce the catch in the southern zones by 45 tonnes (equivalent to reducing the TACC to 104 tonnes). Industry propose to achieve this by preferably(a) shelving 45 tonnes (30%) of ACE which will not be fished for three years or, if the Minister is obliged to make a TACC reduction, by (b) reducing the current TACC by a minimum and shelving the remainder of the 45 tonnes as ACE. Industry proposes to support this catch reduction by maintaining current catch in the northern zones. Industry also has voluntary initiatives to improve the fishery including (i) increasing the MLS from 125 to 127 mm, with the intention of increasing it further in the future, and (ii) a proposed reseeding programme.
    
83. If the Minister is satisfied there is sufficient uncertainty in the stock assessment that it does not provide him with information on whether the PAU 5A stock is below, at, or above the B_MSY he could consider a number of industry options.
    

No TAC reduction with only shelving of ACE

84. If the industry option is solely to shelve ACE and keep the TACC at 148.98 tonnes, then this option is the same as status quo (option three) for the purposes of assessment of setting the TAC under s 13 of the Act. That is, there is no reduction in the statutory TAC. Shelving is not a relevant consideration when setting a TAC under s 13. The Minister must be satisfied that he has set a TAC that will move the stock towards a level at or above the B_MSY, regardless of any voluntary shelving or other arrangements.
    
85. MFish consideration of this option is as set out under option 3. That is, MFish considers that PAU 5A stock is below the B_MSY and, therefore, a TAC reduction is required to move the stock towards a level at or above the B_MSY.
    

Lesser cut in the TAC accompanied by voluntary measures

86. The Minister may opt for a longer term rebuild taking into account industry voluntary measures. He could consider retaining the current TAC is justified in the short term, bearing in mind the uncertainty in the assessment information (i.e. option three). Or the Minister may choose a lesser cut in the TAC (than option one or two) taking an even longer rebuild strategy than option two.
    
87. The Minister does have discretion about the way and rate at which a stock is moved to B_MSY, taking into account social, cultural, and economic factors. The Minister could reduce the TAC by less than otherwise, taking a longer term view of movement back to B_MSY, having regard to the shelving and other initiatives proposed.
    
88. In setting the TAC, the Minister cannot take into account an industry agreement to shelve ACE. However, voluntary arrangements can be considered by the Minister when determining the way and rate at which the stock will be restored to B MSY.
    
89. One scenario put forward by industry is a 45 tonne reduction in total removals using a combination of TAC reduction and shelving.
    
90. The overall probability of rebuilding the spawning biomass can not be calculated for this scenario, as noted for option two, as the status of paua stocks in the northern zones at current catches is not known.
    
91. For southern zones, total extractions (commercial plus non-commercial) will be about 57 tonnes. The proposed harvest from the southern zones will be equivalent to a projected catch falling between the 97 and 67 tonne catch overall with the probabilities given in Appendix 2, Table 8 for rebuild of the fishery in the southern zones. The probability lies between 35-53% for spawning biomass being greater in 2008 than current biomass. In other words, at probabilities around 47-53% the biomass in 2008 will remain about the same as the (already diminished) biomass in 2005. At probabilities around 35-40% the spawning biomass will continue to decline.
    
92. As occurs for option two, this scenario assumes that no reduction in catch levels in the northern zones is required. This assumption may or may not be true. There is an unknown risk that current catches in northern zones are unsustainable. It is highly unlikely that there is a large unexploited sustainable fishery in northern zones. As previously noted, it can reasonably be assumed that the southern zones contain most of the PAU 5A habitat and biomass.
    
93. From the above, it follows that this scenario will, at best, maintain the current (already depleted) biomass and, at worst, allow the current biomass to continue to decline. Hence, it is unlikely that this scenario will provide any rebuilding of spawning biomass.
    
94. As for option two, the status of the stocks in northern zones is not known at current catches. The risk posed by unsustainable catches in northern zones can be mitigated by undertaking research and another stock assessment earlier than is currently scheduled, in 2011. It is proposed that a new RDSI survey be undertaken followed by a stock assessment in 2007 -08 so that a TAC review can be implemented for 1 October 2008.
    
95. The industry proposal reduces the total commercial removals, but not as much as either options one or two. The industry proposal, therefore, has a higher sustainability risk. MFish does not consider that the industry proposal, with a 45 tonne catch reduction, meets the Minister’s requirement to set a TAC that moves the stock at or above the B_MSY for shelving to be taken into account.
    
96. The industry proposal does have a significant advantage of industry buy-in, which is likely to result in better compliance with catch spreading arrangements, the voluntary MLS increase, reseeding, and future development of fisheries plans. The social and economic costs of the industry proposal will be lower than either options one or two.
    

Catch spreading

97. Industry is proposing to impose the catch spreading arrangements by quota owners using contracts with their ACE leases. These leases will specify the amount of ACE that can be caught in southern and northern zones. ACE holders will be able to trade catch rights amongst themselves, so that someone wishing to fish in the northern zone can trade his southern allocation for a northern allocation.
    
98. These arrangements could be used to overcome the socio-economic consequences for small boat owners, identified in option two.
    

Voluntary MLS increase

99. The industry has also recently implemented a voluntary measure of increasing the MLS from 125 to 127 mm, with the intention of increasing it further at a future date. Limited information is available on the effect of an increase in MLS. No analysis has been undertaken for PAU 5A, but a similar proposal for PAU 5B was modelled to project a modest increase (4.3%) in the probability of rebuilding the spawning biomass over five years.
    
100. Evidence suggests that there are differences in the size obtained by paua in different parts of the fishery. An increase in MLS is likely, therefore, to have different impacts in the fishery. An increase in size limit may cause a change in fishing behaviour or an increase in fishing effort in an area. If this were to occur, then the benefits may be increased or diminished depending on the circumstances.
     
101. An increase in MLS is also likely to cause a proportion of paua between 125 and 127 mm to be removed from the reef, and returned. Some of these will die as a result of the damage inflicted during their capture. There is no analysis to estimate the likely severity of this problem.
     
102. The benefits of an increase in MLS are unclear, but there could be benefit to the stock over time.
     

Voluntary reseeding programme

103. Industry are proposing to undertake an expanded reseeding programme in the southern zones as they believe they can increase the paua biomass in the area to what it has been in the past.
     
104. There is poor recruitment in Fiordland. The exposed nature of the coast can result in larvae being flushed away before they settle, as well as poor survival of juvenile paua. MFish has reservations about the success of reseeding in Fiordland because of the exposed conditions. The timing and location of out-planting of the seed paua will be critical to success.
     
105. At present, MFish does not accept reseeding as an alternative sustainability measure. There is no formal evidence that reseeding can contribute to recruited or spawning biomass. Existing reseeding programmes, such as PAU 7, have not been established long enough to provide this evidence. It would not be responsible to rely on reseeding to reduce the impact of a TACC reduction.
     

Statutory Considerations

106. The statutory considerations taken into account in forming these management proposals are set out in Appendix 1. Key considerations are:
     1. The choice between these proposals is one of balancing the risks to sustainability and the uncertainty in the assessment for PAU 5A, while having regard to social, cultural, and economic factors.
     2. Options one and two will likely meet the Minister’s obligations under s 13(2)(b) to set a TAC that moves the stock toward or above a level that can produce MSY. Option one takes the most conservative approach to reducing the risk to sustainability by adopting a faster rebuild rate. Option two seeks to rebuild the stocks in the southern zones and maintaining current catches in northern zones, resulting in an overall slower rate of rebuild for PAU 5A stock as a whole.
     3. Options three and four are the least cautious, emphasising the uncertainty in the assessment pointing to a downturn. MFish considers that the industry proposal does not meet the Minister’s obligations under s 13(2) that the TAC should be set at or move the stock to, or above, the level that can produce the level that can produce the MSY. MFish considers that there is sufficient certainty that, based on the best available information, the PAU 5A stock is below B_MSY. There is evidence in the current assessment that indicates that the current TACC and recent catches, at least in the major area of the fishery in the southern zones, are not sustainable. Setting a TAC to reduce total removals by 45 tonnes is unlikely to result in a rebuild in the PAU 5A biomass to move the stock toward or above a level that can produce MSY.
     4. The industry proposal also provides for shelving of ACE. Shelving on its own does not meet the Minister’s obligations under s 13(2) - that where the stock is below the level that can produce the MSY then the TAC should be set to move the stock to or above the level that can produce the level that can produce the MSY.
     5. A proposal that sets a TAC and shelves ACE may meet the Minister’s statutory obligations (depending on the level the TAC is set at). Section 13(2)(b) provides for moving a stock that is below the level that can produce the MSY toward or above a level that can produce MSY, and can be read together with s 13(3). Section 13(3) provides that the Minister, when determining the way in which and the rate at which a stock is moved towards or above a level that can produce MSY under s 13(2)(b), can take into account, inter alia, economic factors. It is accepted that the Minister does have discretion about the way and rate at which a stock is moved to B MSY, taking into account social, cultural, and economic factors. As part of this exercise, shelving and other voluntary industry arrangements that are addressing the sustainability issues may well be of relevance. MFish considers that a proposal to set a TAC that reduces total removals by 45 tonnes does not meet the Minister’s requirement to set the TAC that moves the stock to a level at or above the B_MSY for these voluntary initiatives to be taken into account. But if the Minister is satisfied there is sufficient uncertainty in the stock assessment that it does not provide him with information on whether the PAU 5A stock is below, at, or above the B_MSY he could consider other options about the way and rate at which a stock is moved to B MSY, taking into account voluntary arrangements.
        

Summary

107. Table 1 summarises the advantages and disadvantages for each of the four management proposals.
     
108. MFish is specifically requesting submissions from stakeholders on:
     1. Undertaking another RDSI survey and a new stock assessment at an earlier date, so that a TAC review can be implemented in October 2008 rather than 2011 as currently scheduled;
     2. Social, cultural and economic consequences of the proposed options of TAC/TACC reductions; and
     3. Voluntary catch splitting arrangements to support options two and four.
        
109. MFish is specifically requesting submissions from the Fiordland Marine Guardians to meet the requirements of the Fiordland (Te Moana o Atawhenua) Marine Management Act 2005.
     

Table 1: Comparison of the advantages and disadvantages of the four management proposals.

¹ Southern zones are defined as the three research zones labelled ‘Dusky’, ‘Chalky’, and ‘South coast’ on Figure

² The northern zones comprise the remainder of PAU 5A north of Dusky zone.

² No TAC or allowances have been set for PAU 5A; a TACC only was set when PAU 5A was established in October 1995.

³ In reference see charts NZ 76, NZ7612, NZ7614, NZ7522, NZ7413 and topomaps A44-45, B41- 47, C40-41, C46, D38-40, D46.

⁴ Spawning biomass is the proportion of the stock above 97mm, 50% of paua are mature at this size.

⁵ Recruited biomass includes paua > 125mm minimum legal size, ie, fish that are large enough to be taken by fishers.

⁶ Exploitation rate is the percentage of the total population of legal sized paua that is taken annually.

⁷ McShane, P., Mercer, S., and Naylor, R.: Surveys of southern stocks of paua. NZ Professional Fisherman, April 1992, p 29-33.