Kahawai FAP

Kahawai Final Advice Paper

Ministry of Fisheries

29 June 2004

65. Other sources of information raised in submissions as a means of inferring trends in kahawai abundance and a discussion of these issues is provided in Appendix 1.
66. In summary, recreational fishers have expressed strong concerns over what they perceive is a marked decline in the amount of kahawai available to them in recent years. A considerable volume of submissions supports this perception. Reference is made in submission to perception surveys, fishing competition records, tagging analysis, length based studies and recreational CPUE supporting this view.
67. Industry suggests that there is a lack of information to support any suggestion of a decline in stock size and refers to aerial sightings, trends in commercial bycatch and recreational sampling information in support of this view. There is conflicting information making it difficult to confirm either claim.
68. None of the other sources of information presented in Appendix 1 is definitive with regard to determining recent trends in the stock and the current state of the kahawai biomass. Recreational submissions acknowledge that perceptions about stock status vary by area, other information is limited in extent and usefulness as an index of abundance.
69. The limited scientific evidence available does not suggest that there have been major changes in recreational catch rates or reductions in the size of kahawai available to recreational anglers. Recent recreational harvest survey estimates are now considered the best available information on recreational catch. The current estimate of 4 025 tonnes of kahawai (higher than the commercial catch) does not in itself support the widespread perception of respondents that the fishery has declined in availability.
70. Equally there is only limited information to support the case that there has been no further decline in the kahawai stock. While perceptions of fishers may be considered to have a lesser weighting than the limited scientific information available they also constitute information. MFish does not discount anecdote but considers that you should weight it accordingly.
71. MFish notes the Sanford submission that it is axiomatic that harvesting will have led to a reduction in biomass. With a species such as kahawai that is highly visible because of its surface habit, it will be more noticeable to recreational fishers as the size of the stock is reduced towards BMSY. Further, a reduction in the size of fish might be expected as larger older fish are removed during harvesting and replaced by smaller more productive fish. At issue is whether the biomass has declined to a point that a rebuild of the stock is necessary or desirable.