Kahawai FAP

Kahawai Final Advice Paper

Ministry of Fisheries

29 June 2004

Estimates of recreational landings

80. MFish’s initial TAC proposals used an estimate of recreational landings based on an average (with some adjustment) of the 1996 and 1999-00 recreational diary surveys.

81. Submissions specified the following alternatives:

1. 1999-00 recreational survey only (Non-Commercial Fishers); and
2. 1996 diary survey only based on this being the only accepted estimate (Sanford).

82. Recreational fishers say that their landings have declined but argue that the 1999-00 recreational harvest survey should be used to define their utilisation.
83. NIFCL recognises the inherent problems with the recreational diary surveys and believes that any advice over the robustness and acceptance of the presumed recreational catch should be qualified.
84. TOKM accept the estimate of recreational use proposed in the IPP suggesting changes only to estimates of commercial use.

85. Estimates for the recreational catch of kahawai have been derived from regional telephone/diary surveys conducted from 1991-92 to 1993-94, and three national telephone diary surveys undertaken in 1996 [6], 1999-00 [7] and 2000-01 [8].
86. The most relevant surveys are the three national telephone diary surveys. The results of these surveys are summarised in Table 3. The harvest estimates for 2000-01 are preliminary.
87. The 1999-00 survey for all fishstocks produced harvest estimates that were considerably greater (up to 300%) than the 1996 survey. Although the general methodology of using a telephone/diary survey was the same for all surveys, there were important differences in the details that could have accounted for the differences between estimates. An independent review advised caution in using the 1996 estimates as absolute harvest estimates without further analysis and also cautioned against the use of the estimates for QMA2 for the 1999-00 survey. These considerations lead MFish to conclude that the recreational use of kahawai lay in a range between 1996 estimates and 1999-00 and an average of the two was the best reflection of current recreational utilisation.
88. In determining an average between surveys to represent current recreational utilisation an adjustment of survey results was required to take into account specific new stock boundaries for kahawai. Catch estimates for KAH 2 and KAH 3 for 1999-00 were considered to be too high and were replaced by provisional estimates from the 2000-01 survey for this stock.
89. A meeting in December 2003 of technical members of the Recreational Working Group examined the methodologies used for each of the 1996, 1999-00 and 2000-01 surveys. The Recreational Working Group considered that the 1996 results should not be used as absolute estimates of recreational catch. Overall the estimates for 1996 were considered at that time to be substantially under-estimated. More recently the 1996 estimates are reported as containing methodological errors and they are considered to be unreliable. Given the size of the more recent estimates of recreational catch MFish considers that it is possible that 1996 estimates of recreational catch remain under-estimates.
90. More recent advice from the technical members of the Recreational Working Group is that the estimates of recreational catch from the 1999-00 and the 2000-01 surveys may be implausibly high for some important fisheries and have cautioned against their use.
91. MFish considers that the 1999-00 estimates of catch for KAH2 and KAH 3 are implausibly high and this is reflected in the approach adopted in the IPP to exclude these estimates from the average figures presented in the IPP and to use instead provisional estimates from 2000-01. This conclusion was based on a comparison between surveys and between estimates for each stock. For example it was not considered to be realistic that the 1999-00 estimates of recreational kahawai catch for KAH 2 exceeded those for KAH 1 (refer Table 3). The recreational fishery in KAH 1 is generally considered to be much larger than any other area of the country.
92. For other stocks MFish notes that 1999-00 and 2000-01 estimates are substantially higher than those for 1996 but is not able to say that they are implausibly high. Given the technical concerns relating to the 1996 recreational harvest estimates and the absence of a current assessment model there are no other reference points for kahawai.
93. The recreational fishery for kahawai is either a target troll or lure fishery (based on surface or spatial aggregations of fish) or is taken as a bycatch of fishing using baited hooks. MFish notes that the 2000-01 harvest survey reported kahawai was the second most harvested finfish nationally and the SACEs survey reported that kahawai was the second most important of the five key recreational species it evaluated by value. It is possible that large catches could be realised by recreational fishers target fishing for kahawai. Further, the high recreational catch (estimates now exceed the commercial catch) may explain in part the recreational perceptions that stocks of kahawai have continued to decline in abundance despite the constraint on commercial catches.
94. However, to take account of the views of the technical members of the Recreational Working Group, MFish now proposes taking the lower of the 1999-00 and 2000-01 estimates for each kahawai stock as a basis for determining current recreational use for that stock and nationally.
95. Table 3 shows the recreational allowance as proposed in the IPP compared with the equivalent estimates of the recreational harvest for each QMA for the 1996, 1999-00 and 2000-01 surveys. Also shown in the table is the best estimate of current recreational use that MFish is able to construct from these surveys based on advice to date.
    
    

96. In conclusion, internal and external experts have reviewed the 1996, 1999-00 and 2000-01 recreational surveys. Since the IPP was released the Recreational Working Group has confirmed that the 1996 estimates contain methodological errors and should not be used as absolute estimates of recreational catch. Technical advice is that even the results from the 1999-00 and the 2000-01 surveys should be treated with caution, as some estimates are implausibly high for some important fisheries.
97. MFish now proposes basing estimates of recreational current utilisation of kahawai on the lowest of the estimates for each stock from the 1999-00 and 2000-01 surveys as outlined in Table 3. Despite the uncertainty in the recent estimates of recreational catch MFish considers that these constitute the best available information with which to determine the current recreational utilisation of the kahawai fishery and with which to consider an allowance for recreational fishing interests.
98. MFish has relied on expert advice from the Recreational Working Group regarding the reliability of survey results when deciding on the best estimates of current recreational use of kahawai. MFish acknowledges that the Pelagic Working Group has not reviewed the alternative estimates presented. This is an issue of particular concern to Sanford, which suggests that the recent estimates should not be used because of this. You should be aware of and take into account this concern when considering the alternative estimates of current recreational utilisation proposed. However, MFish reiterates the current advice that the 1996 recreational survey (the Sanford preferred option) contains methodological errors and the estimates should not be used.

[6] Bradford, E. (1998) Harvest estimates from the 1996 national recreational surveys. Fisheries Assessment Research Document 98/16.

[7] Boyd, R.O., Reilly, J.L. (2004) 1999/2000 National Marine Recreational Research Survey: harvest estimates. Draft New Zealand Fisheries Assessment Report 2004/April 2004.

[8] Boyd, R.O., Gowing, L, Reilly, J.L. (2004) 2000/2001 national marine recreational research survey: diary results and harvest estimates. Draft New Zealand Fisheries Assessment Report 2004/May 2004.