REC2001-02 Survey Marine Recreational Fishing North Otago Final
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Taihoro Nukurangi North Otago Marine Recreational Fishing Survey 2002/2003 G. D. James M. J. Dnwin Final Research Report for Ministry of Fisheries Project REC2001/02 National Institute of Water and Atmosphere Research July 2003 Final Research Report Report Title North Otago Marine Recreational Fishing Survey 200212003 Authors G. D. James; M. J. Unwin 1. Date July 2003 2. Contractor NIWA 3. Project Title Survey of Recreational Fishing in the Oamaru area 4. Project Code REC2oo1l02 5. Project Leader G.D.James 6. Duration of Project Start date July 2002 Completion date September (now October) 2003 7. Objective: To characterise the recreational fishery off the Oamaru coastline for management purposes. Specifically: To determine the areas fished, species targeted and caught, and methods used by recreational fishers off the Oamaru coastline. 8. Executive Summary The recreational fishery along the North Otago coast was surveyed over the six months from October 2002 to March 2003. Data on areas fished, fishing effort, fishing methods used, and numbers of all species caught, kept, and released, were collected via boat ramp interviews with private fishers, and via fishing diaries maintained by charter vessel operators. Almost all recreational fishing recorded during the survey was done by rod and line, with netting, diving, hand gathering, and potting recorded only rarely. Most fishing was recorded between Cape Wanbrow and Lookout Bluff, in the central areas of the survey region. The fishery was dominated by blue cod, which was the species most frequently targeted and caught, and made up 63% of the total catch. Hapuku was the next most frequently targeted species, particularly by charter vessels which are generally larger than private vessels and can fish further offshore, but comprised only 4% of the catch. Other common species caught incidentally were sea perch, spiny dogfish and red cod, which made up 16%, 7%, and 5% respectively of the catch. Temporal and spatial variability in catch rates for most commonly caught species was low, suggesting the fishery is relatively uniform throughout the survey 1 region. Catch,rates for hapuku were higher towards the end of the survey period, although these data are strongly influenced by records for one charter operator. Approximately 78% of blue cod caught were retained by fishers, along with 85% of sea perch, 55% of red cod, 100% of hapuku and tarakihi, and 99% of trumpeter, but only 12% of spiny dogfish and 19% ofbarracouta. Anecdotal information collected during the survey highlighted several issues of potential relevance to fisheries managers. Participating charter vessel operators used only rod and line, but there were anecdotal reports that significant quantities of blue cod were being potted by a few charter vessel operators, and some concern that this was endangering the fishery. fu addition, one experienced charter vessel operator indicated that the size of blue cod had decreased this season, along with an increase in the number of private boats observed fishing. To promote sustainability of the fishery, local fishing clubs recently introduced a voluntary reduction in daily bag limits which has apparently met with widespread support. 9. Methods A survey developed by NIWA to characterise the recreational fishery off the North Otago coastline was conducted from 1 October 2002 through 31 March 2003. It comprised two principal data collection techniques - a diary of fishing activities for charter vessel operators, similar to that used in the earlier national survey of recreational fishing from charter vessels (James & Unwin 2000), and boat ramp interviews of private fishers conducted at each of the three boat ramps in the region. In addition, opportunities were taken to seek information on . the fishery from local fishers, including those prominent in local fishing clubs. The region was divided into four similarly-sized areas (A to D) (Fig. 1) based on readily recognisable coastal features. We also added a fifth area (E), to the south of the survey region; because it included the Moeraki boat launching ramp which was frequently used by fishers to gain access to the main survey region. Although four charter vessel operators were known to work in the area (three of whom are regulars), only two (including the intermittent operator) were prepared to complete diaries. Data from these two operators are presented here, and whereas we cannot be sure that they are representative of the total charter fleet, it is likely that they are broadly similar. Conversations with the non-participants suggested that their main concern was that any information they provided might subsequently be used against them. Copies of the diary sheets are provided in Appendix 1. Boat ramp interviews were conducted by locally contracted persons at all three boat ramps in the region - Oamaru, Kakanui, and Moeraki (Fig. 1)- over the six month survey period. Two persons were employed to monitor each of the Oamaru and Moeraki ramps, with one person covering Kakanui. These five persons were contacted by phone, then visited, provided with a boat ramp interviewing kit, and instructed in how to complete good records. All were retired men who had had a major involvement in the recreational fishery over the years, and were keen to assist in collecting data which could contribute to better management. We provided them with NIW A name badges, and none reported major problems with uncooperative fishers. Regular phone calls and occasional personal visits were made to ensure continuing collection of good data. The interviewers were keen to provide useful extra information 2 related to activities of the recreational fishery, which has been helpful in drafting some of the conclusions for this report. At the end of the survey period, letters of thanks were sent to the interviewers, together with gift vouchers of appreciation. Copies of the interview instructions and recording form are also provided in Appendix 1. Both the diary and boat ramp interview forms allowed for collection of additional information to that specified in the tender, namely data on number of fishers, whether fishers were from NZ or overseas, hours fished, and the number of each species caught (both kept and released). Information on effort enabled estimation of catch rates for the major species by area and month, which in turn allowed for examination of variability in the relative abundance of species, which is otherwise often obscured by changes in fishing effort. Diaries and boat ramp interviews would be expected to cover all recreational fishing methods employed in the area, except hand gathering. It was concluded that it was impractical to try to assess the importance of hand gathering as part of this survey, as the frequency of activity along this coastline is too low to be practically sampled. Data were entered into a Microsoft Access database, and analysed using Microsoft Excel pivot tables. There was some confusion in this area over the common names for wrasse species, but we established that in general "wrasse" referred to banded wrasse, and "parrotfish" to scarlet wrasse/red parrotfish. Use of sevengill shark in this report refers to broadnosed sevengill shark. 10. Results Fishing effort A total of 333 boat ramp interviews were undertaken, 121 at the Oamaru boat ramp, 150 at Kakanui, and 62 at Moeraki (Table 1). Peak activity (65-86 interviews per month) was recorded in December, January, and March, with lower but still significant activity (23-45 interviews per month) at other times. Interview location was most variable during spring, when bad weather was common, with little activity at Kakanui and Oamaru but considerably more at Moeraki where there is a sheltered launching site. Eighty percent of fishers interviewed fished in areas B and C (Fig. 1, Table 2), with areas A and D receiving relatively little use. Number of fishers, hours fished and fisher-hours were distributed similarly by area and month (Table 2). Diarist data from charter vessels are more limited, but showed a similar pattern to the boat ramp interviews, with areas B and C the most frequently fished (Table 3). The number of fishers, hours fished and fisher-hours were distributed similarly by area and month (Table 3). As noted earlier only two charter operators maintained diaries, and they operated in different areas, with one fishing principally in areas B and C, but also area A, and the other only in area D. Their level of effort also varied greatly, with the latter diarist making only 10% of total diarist trips. Only 3% of fishers on charter vessels were overseas visitors. 3 Of the 333 trips for which interview data were collected, 94% targeted blue cod, 5% hapuka, and 1% other species (crayfish, red cod, paua, and kina). This pattern was markedly different to that of charter vessels, where of the 50 diarist trips, 68% targeted hapuka, and 32% blue cod. By far the most popular fishing method was rod and line, which was used on 331 (99.4%) of interview trips. Two trips (0.6%) also used set netting, and a further two also used diving (for rock lobsters). The remaining two interviews were for diving trips, one for kina and the other for paua. All charter vessel trips for which we have records used lining only. Catches Blue cod was by far the most common species caught by lining, making up 63.2% of the total catch by number (Table 4). Sea perch comprised 16.5% of the catch, followed by spiny dogfish (7.4%), red cod (4.9%) and hapuku (3.9%). Barracouta, tarakihi and scarlet wrasse were the next most abundant (each comprising 0.5%-1.3% of the total), with another 17 species making up the remaining 1.6%. Moki and elephant fish were the only species recorded caught in set nets (Table 4), but effort was very small and other species such as butterfish (known locally as greenbone), and some wrasses are also known to be caught by this method.