UNPUBLISHED REPORT No. 5 REPORT ON THIRD VISIT THE COOK ISLANDS

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1 SOUTH PACIFIC COMMISSION UNPUBLISHED REPORT No. 5 REPORT ON THIRD VISIT TO THE COOK ISLANDS 16 February 20 July 1983 by P.D. Mead Masterfisherman South Pacific Commission Noumea, New Caledonia 1997

2 ii The South Pacific Commission authorises the reproduction of this material, whole or in part, in any form provided appropriate acknowledgement is given This unpublished report forms part of a series compiled by the Capture Section of the South Pacific Commission's Coastal Fisheries Programme. These reports have been produced as a record of individual project activities and country assignments, from materials held within the Section, with the aim of making this valuable information readily accessible. Each report in this series has been compiled within the Capture Section to a technical standard acceptable for release into the public arena. However, they have not been through the full South Pacific Commission editorial process. South Pacific Commission BP D Noumea Cedex New Caledonia Tel.: (687) Fax: (687) spc@spc.org.nc Prepared at South Pacific Commission headquarters, Noumea, New Caledonia, 1997

3 iii SUMMARY The South Pacific Commission's Deep Sea Fisheries Development Project (DSFDP) visited Rarotonga, in the Cook Islands, for the second time between 16 February and 20 July 1983, under the supervision of SPC Masterfisherman Paul Mead. An earlier visit to the Cook Islands was conducted at Aitutaki by the DSFP Projects' predecessor, the Outer Reef Artisanal Fisheries Development Project, in This visit followed a request from the Government of the Cook Islands for assistance in diversifying local artisanal fisheries through the demonstration of various techniques, recently undergoing development trials by the DSFDP, which target the deep-swimming tunas associated with fish aggregation devices (FADs). A secondary aim was to conduct a follow-up survey of deep-bottom fish resources and to provide further training in deep-bottom fishing techniques. Due to difficulties in obtaining suitable bait and an unusual scarcity of the tunas targeted by the FADassociated fishing methods, the emphasis of the Project's work programme was changed during the course of the visit in favour of deep-bottom fishing. An extensive survey of deep-bottom grounds and fish stocks was completed, during which trials were conducted on the fishing productivity of two different anchoring methods. During fishing trials, gear rigging, fishing technique, fish handling and general seamanship were demonstrated to a total of 17 trainees recruited from both the local Ministry of Marine Resources and the private sector. Thirty-four fishing trips were completed, most of which combined a variety of fishing methods, and 707 fish were taken with a total weight of kg. Fully 89 per cent of the catch was of locally saleable species which found a ready market in Rarotonga. The results of the Project's deep-bottom surveys and fishing activities supported earlier reports that deep-bottom resources off Rarotonga are generally impoverished and unlikely to support even smallscale dedicated exploitation. It was noted however, in consideration of local commercial fishing activity, that deep-bottom fishing could provide a valuable supplement to catches at relatively little capital outlay or increased operational expense. Although the scheduled work programme in FAD-associated gear development trials was curtailed the limited results obtained indicated that, under certain circumstances, the techniques attempted could produce worthwhile catches and that further investigation and development of these techniques should be encouraged.

4 v RÉSUMÉ Sous la direction du maître de pêche de la CPS, Paul Mead, les responsables du projet de développement au demi-large de la Commission du Pacifique Sud ont séjourné pour la deuxième fois à Rarotonga (Îles Cook), du 16 février au 20 juillet Une mission avait déjà été organisée en 1976/77 à Aitutaki (Îles Cook) dans le cadre du projet de petite pêche à l'extérieur du récif, qui a précédé le projet de développement de la pêche au demi-large. Cette mission a fait suite à une demande d'aide adressée par les autorités des Îles Cook qui ont souhaité diversifier la pêche artisanale locale en envoyant des stagiaires assister à des démonstrations de diverses techniques de pêche que les responsables du projet avaient récemment mises au point en procédant à divers essais. Ces techniques ciblaient les thons évoluant dans les grands fonds à proximité des dispositifs de concentration du poisson (DCP). La mission a eu pour second objectif de réaliser un suivi sur les ressources halieutiques de grand fond et de compléter la formation aux techniques de pêche de grand fond. En raison des difficultés à obtenir des appâts convenables et de l'inhabituelle pénurie de thons ciblés par les méthodes de pêche autour des DCP, les activités prévues au titre du projet ont été remplacées au pied levé par des opérations de pêche de grand fond. Les responsables du projet ont mené à bien une vaste étude des grands fonds et des stocks de poissons, au cours de laquelle ils ont testé la productivité de deux méthodes différentes d'ancrage. Lors de ces essais, ils ont fait des démonstrations de montage de l'engin, de techniques de pêche, de manipulation du poisson et de matelotage (aspects généraux) aux 17 stagiaires sélectionnés au sein du ministère des Ressources marines et du secteur privé. Ils ont organisé 34 sorties en mer, dont la plupart ont permis d'expérimenter plusieurs méthodes de pêche. Ils ont capturé 707 poissons, d'un poids total de 970,4 kg; pas moins de 89 pour cent du volume des prises étaient composés d'espèces vendables localement sur le marché de Rarotonga constituant un débouché tout trouvé. Les résultats des études et des activités de pêche menées dans les grands fonds dans le cadre du projet ont confirmé les conclusions de rapports précédents selon lesquelles les stocks des grands fonds, au large de Rarotonga, se sont dans l'ensemble apauvris, à tel point que même une petite exploitation artisanale spécialisée est très difficile à envisager. Toutefois, compte tenu de l'activité de pêche commerciale locale, on a constaté que la pêche au grand fond pouvait constituer un complément utile à d'autres formes de pêche, moyennant une mise de fond ou une augmentation du coût d'exploitation relativement faibles. Bien que les activités prévues dans le cadre des essais de perfectionnement des engins de pêche associés aux DCP aient été écourtées, les maigres résultats obtenus ont indiqué que, dans certaines circonstances, les techniques qui ont été expérimentées pourraient permettre de réaliser des prises intéressantes et qu'un complément d'étude et de perfectionnement de ces techniques serait donc souhaitable.

5 vii ACKNOWLEDGMENTS The South Pacific Commission gratefully acknowledges the co-operation and friendly assistance afforded the Masterfisherman during the Deep Sea Fisheries Development Project visit to Rarotonga. Particular thanks are due to the Secretary for Marine Resources, Mr Julian Dashwood, his staff and his family, and especially fisheries counterpart officer Mr Ruru Moate. In addition thanks are due to Mr Robert Kiwala, Mr Tekake Williams, Mr Grant Priest and Mr Ron Powell, who together possess a broad range of skill and knowledge in local fisheries and whose advice and encouragement played a large part in the Project's success.

6 ix CONTENTS 1. INTRODUCTION 1 2. BACKGROUND General Existing fisheries 4 3. PROJECT OPERATIONS General Boats and equipment Fishing methods Training activities Post-harvest handling and disposal of the catch Data collection 9 4. FISHING ACTIVITIES AND RESULTS General Deep-bottom handreeling Trolling Vertical longlining Deep-bottom longlining, ika shibi fishing 16 and shallow-water handlining 4.6 Catch and effort summary DISCUSSION AND CONCLUSIONS REFERENCES 18 Page APPENDICES 1. List of basic equipment required for deep-bottom 21 handreel fishing 2. Operational aspects of fishing trips Standard fishing data collection form 25 4a. Species composition of the deep-bottom dropline catch 27 4b. Species composition of the troll catch 31 4c. Species composition of the shallow-water handline catch 33

7 1 1. INTRODUCTION The South Pacific Commission's Deep Sea Fisheries Development (DSFD) Project is a mobile villagelevel rural development project which operates in Pacific Island nations at specific Government request, and which has the following broad objectives: To promote the development or expansion of artisanal fisheries throughout the region, based on fishery resources which are at present underutilised, in particular the deep bottom resources of the outer reef slope; To develop and evaluate new simple technology, fishing gear and techniques suitable for use by village fishermen, which will enable fishermen to substantially increase catches while reducing dependence on costly imported fuels; and To provide practical training in appropriate fishing techniques to local fishermen and government fisheries extension workers. The DSFD Project superseded an earlier SPC programme, the Outer Reef Artisanal Fisheries Development (ORAFD) Project, in The ORAFD Project visited the Cook Islands during 1975/76 and surveyed deep-bottom fish resources at Aitutaki island. A later visit by the DSFD Project during 1981/82 operated at Rarotonga and Penrhyn islands, conducting a similar survey and an assessment of the potential economic viability for the development of a deep-bottom fishery at those sites. The report of that visit (Taumaia and Preston, 1985) concluded that 'true commercial deep-bottom dropline fishing activities by smallscale operators (were not then) feasible in either of the locations fished'. The relatively impoverished state of deep-bottom resources at Rarotonga (where a catch rate of 1.9 kg of fish per reel hour was recorded) and the lack of marketing opportunities at Penrhyn (despite the apparent presence of substantial deep-bottom stocks indicated by the 8.4 kg per reel hour catch rate recorded) were noted as obvious curbs to commercial development. The current visit followed a request by the Government of the Cook Islands for assistance in encouraging diversification in local artisanal fishing, especially through developing effective techniques to exploit fish aggregation devices (FADs). The Project operated at Rarotonga for five months from 16 February to 20 July 1983, under the supervision of SPC Masterfisherman Paul Mead. This was the DSFD Project's forty-fifth country visit, the third visit to the Cook Islands by an SPC fisheries development project. The specific objectives of the visit were: To refine vertical longline gear and techniques which were developed and used with some success during an earlier Project visit to Niue (Mead, in press); to conduct trials aimed at improving subsurface trolling techniques and gear; to further investigate the state of deep-bottom resources around Rarotonga; to provide extension training and demonstration to Marine Resources fisheries officers and private fishermen as opportunity permitted. Due in large part to the unseasonal scarcity of the fish species targeted by the methods proposed for gear development work, this aspect of the visit was curtailed in favour of further deep-bottom survey work and deep-bottom fishing technique demonstration.

8 2 2. BACKGROUND 2.1 General The fifteen islands of the Cook Islands (Figure 1), which fall naturally into the northern and southern groups, total about 240 sq km of land, but because the islands are widely scattered the country's Exclusive Economic Zone encompasses some 1,969,448 sq km of ocean (SPC estimate), the sixth largest in the SPC region. The islands of the northern group are typical coral atolls. The southern group islands, apart from the tiny atolls of Manuae and Takutea, are volcanic in origin. Most of the southern islands have elevated, encircling reef platforms adjacent to the coast, and all are surrounded by recent coral reefs. These six islands have soils which range from heavily weathered and infertile in the older islands to the highly productive younger soils of Rarotonga. Most of the southern islands, and particularly Rarotonga, support rich and varied vegetation. Subsistence and small-scale commercial agriculture is widely practised, with coconut, breadfruit, taro, arrowroot, citrus fruits, banana, papaya and pineapple grown. In recent years an export-based agricultural industry has developed in market-garden produce such as tomatoes, beans, sweet peppers and courgettes. The Cook Islands lie within the hurricane belt and are influenced by the prevailing trade winds. In the north these winds are mainly from the east and in the southern group from east south-east. During the hurricane season (November to March) humidity is high, but during the remainder of the year the southern group is generally cooler than the north. The mean annual temperature at Rarotonga is 24 C and the average annual rainfall 2000 mm (Anon, 1986). A census conducted in 1981 estimated the country's population at 17,754 (Navunisaravi and Naroba, 1985), with 9,530 on Rarotonga, and this figure demonstrates a steady decline in population over recent years, abetted by Cook Islanders' status as New Zealand citizens and the immigration access this status gives to Australia and New Zealand. More than 20,000 Cook Islanders now live, more or less permanently, in New Zealand. The local economy is heavily dependent on imports of foods, raw materials and manufactured goods. Imports to the end of December 1983 were valued at NZ$35,087,000, of which NZ$7,488,000 comprised food stuffs (Navunsaravi and Tuatai, 1985). Exports in the same year were valued at NZ$4,890,000, of which clothing, citrus juice and bananas were important components. Tourism also plays an ever-increasingly important role in generating foreign revenue. Exports of unprocessed fisheries products were restricted to NZ$140,000 in 1983, almost wholly comprising raw mother-ofpearl and trochus shell (Navunisaravi and Tuatai, 1985).

9 3 Figure 1. The Cook Islands

10 4 2.2 Existing fisheries Fisheries activities throughout the group are widespread and diverse, though generally at subsistence level. The main artisanal methods employed include gill-netting, bottom and mid-water handlining, trolling, the scooping of flying fish and spearfishing (Brown, 1981). The annual artisanal catch in the southern group has been estimated at 800 to 1000 tonnes, comprising about 70 per cent 'reef fish', 10 per cent pelagic species and the balance 'miscellaneous' fish including sharks (Anon, 1980). Mid-water handlining or 'dropping stones', known locally as 'palu ahi', for deep-swimming tunas has been an important traditional fishing method, but the Cook Islanders do not have a tradition of bottom fishing on the outer reef-slope (Brown, 1981). At many of the outer islands catches by these various methods often exceeds demand and simple preservation techniques such as salting and drying are often employed to store surplus catches. At Rarotonga, where population has steadily increased with the flow of population from the outer islands, and where a cash economy prevails, the supply of local fish falls far short of demand (Anon, undated) and a number of attempts have been made to develop catch collection systems that would give outer island fishermen access to the Rarotongan market. Such schemes, both private and government, have met with only limited success, constrained by unsuitable shipping facilities and lack of catch handling infrastructure at the fishing sites, though at the time of this visit irregular consignments of reef and pelagic fish were delivered to Rarotonga from Palmerston and Penrhyn atolls. The Cook Islands Government Fisheries Division is headquartered at Rarotonga and, at the time of this visit, was equipped with a 10 tonne capacity blast freezer and a 3 tonne capacity holding freezer, as well as a Northstar 0.5 tonne/24 hour ice-making machine. The Fisheries Division has involved itself in a number of attempts to develop various fisheries as commercial activities in the outer islands, most notably the introduction of trochus or topshell (Trochus niloticus) to Aitutaki in 1956 (and subsequently to other islands) and the support of pearl shell (Pinctada margaritifera) farming in the northern atolls of Manihiki and Penrhyn. Fisheries Division has also sought to boost offshore catches at Rarotonga and a number of the outer islands by undertaking a programme of fish aggregation device (FAD) deployment. This programme has met with considerable success, although plagued by gear losses. The catch of fresh fish at Rarotonga demands high prices for almost all species, and the better part of the catch by the few commercial operators is diverted to the tourist hotel and restaurant trade. At the time of this visit no fishermen were regularly engaged in deep-bottom fishing along the outer reefslope. 3. PROJECT OPERATIONS 3.1 General All 34 fishing trips completed during this visit originated from Rarotonga's main harbour at Avatiu (see Figure 2) and were conducted offshore aboard either one of two 8.9 m 'alia' catamarans. Most trips were made during daylight and lasted from 6 to 11 hours, although four longer, overnight trips were also completed. Trips usually combined a variety of fishing methods. A typical trip would include trolling along the outer reef drop-off, perhaps with passes around an offshore FAD on the outward and return journeys but with most fishing effort devoted either to bottom droplining or vertical longlining. The gear development work referred to in Section 1 included mid-water handlining for tuna by the 'ika shibi' method, sub-surface trolling, and vertical and bottom longlining. Table 1 summarises Project activities during the 5 months of the visit.

11 5 Table 1. Summary of activities Date Activity 16 February - 24 February 1983 Arrive Rarotonga, clear Customs, unpack and sort gear. One familiarisation trip to FADs. 25 February - 19 March Four familiarisation trips, including overnight bottom fishing trip. 20 March - 16 April Fishing trips between periods of heavy seas. 17 April - 30 April Heavy seas continued. Rigging of reels and gear on newly-delivered private fishing boat. 1 May - 28 May Fifteen fishing trips completed, including three overnight trips, 50 per cent of trips aboard private craft. 29 May - 24 June Nine fishing trips completed. 12 July Final trip completed, check on missing fish trap. 13 July - 20 July Packing and departure Figure 2. Rarotonga showing Project base and consistently productive fishing sites

12 6 Prevailing winds during this visit were south-easterly with occasional shifts to the east and northeast, and rough seas were common during heavy blows. Intervals of light variable westerlies and calms enabled fishing to be conducted right around the island and a fairly comprehensive sampling of bottom-fishing grounds completed. This was not possible during the earlier DSFD Project visit (Taumaia and Preston, 1985) due to the persistently strong south-easterlies which prevailed then. 3.2 Boats and equipment Two 8.9 m FAO-design 'alia' catamarans (Figure 3) manufactured in Western Samoa, were used as fishing platforms during this visit, one owned by the Cook Islands Ministry of Marine Resources and the other imported by a private fisherman. The Fisheries Division alia was driven by a 35 hp longshaft Evinrude outboard motor and the private boat by a 40 hp ultra-longshaft outboard. The private vessel had the outboard mounted one crossmember forward of the stern while the government boat's motor was mounted two cross-beams forward. The sternmost mounting on the private boat proved to provide greater manoeuvreability and also avoided the cavitation commonly experienced with this boat design. Cavitation was a constant problem for the government alia in all but the calmest seas. In slight sea conditions the private vessel attained a top speed, when lightly laden, of knots. The government craft in the same conditions was capable of only 8 9 knots. Both craft consumed comparable quantities of fuel at cruising speeds of 5 7 knots. Figure 3. FAO-design 'alia' catamaran of the type used at Rarotonga The fishing gear carried aboard each vessel was similar. Four FAO-design, Western Samoan type wooden handreels (Figure 4) bearing 500 m of kg test nylon monofilament were mounted on each boat. For trolling, lines from the forward pair of reels were run out through line guides at the tip of 3 m trolling booms fixed to the cabin top. This spread allowed the forward and sternmost reels to be trolled simultaneously without undue problems of fouling.

13 7 Each boat was also equipped with 600 m of 8 mm diameter polypropylene anchor rope, 5 m of 10 mm diameter chain and a grapnel anchor constructed from 12 mm diameter reinforcing rod. A l displacement inflatable balloon buoy, fitted with a snap-shackle which could be clipped onto the anchor warp for hauling, was also carried (see Figure 5). The Fisheries Division catamaran was fitted with a Koden SR-657 echo-sounder and a VHF radio. The private boat carried the Project's JMC 707 portable echo-sounder. Both echo-sounders could be powered by an internal 12 volt system supplied by 'D' size torch batteries. Appendix 1 gives a detailed list of basic gear required for deep-bottom fishing. Figure 4. FAO-design Western-Samoan type, wooden handreel

14 8 Figure 5. Self-hauling anchor gear 3.3 Fishing methods Of the 277 hours spent at sea off Rarotonga, 215 hours were logged in actual fishing operations by a variety of methods. Deep-bottom handreeling, which was originally envisaged as occupying only a secondary role during this visit, actually became the predominant technique employed as the Masterfisherman adjusted his schedule of activities as earlier described. Fishing effort was recorded as follows; deep-bottom handreeling 110 hours, trolling 60 hours, vertical longlining 18 hours, and 27 hours variously engaged in ika shibi fishing, shallow-water handlining and bottom-longlining. A summary of the fishing effort by each method during each trip, and the catch recorded, as well as fuel and bait expended, is contained in Appendix Training activities The Masterfisherman worked in close consultation with Mr Julian Dashwood, Cook Islands Secretary for Marine Resources and his staff, regarding the demonstration of fishing techniques and the gear development trials, with the aim of including both Fisheries Division staff and interested local fishermen in the programme. While operating from the government catamaran, Mr Ruru Moate of the Fisheries Division worked directly with the Masterfisherman as counterpart officer and proved to be a willing and capable boat captain and fisherman. A total of 17 individuals participated in fishing trips aboard either the government or the private catamaran, including 7 Fisheries Division staff. Most training was practical with trainees participating as fully as possible in fishing activities. Fishing methods to which training time was devoted included deep-bottom fishing using fixed and Parachute sea-anchoring systems, shallow-water handlining, bottom longlining, vertical longlining and subsurface trolling with wire lines. A good deal of time was spent between trips supervising and demonstrating the rigging of gear and in informal discussions of topics such as small-boat handling, fishing site selection and aspects of fishing techniques. 3.5 Post harvest handling and disposal of the catch Neither of the alias employed were equipped with integral or portable ice-boxes. To assist in preserving catches a 2 m long insulated fish bag containing kg of ice was carried on all trips. This zippered bag, manufactured in Hawaii under the 'Ice'n Brine' trademark, had sufficient capacity and insulating ability to hold over 100 kg of fish and ice for up to 24 hours. The bag proved to be quite efficient and of adequate size to preserve a day's catch, and it was light and easily stored and cleaned.

15 9 Fish were packed in ice in the bag immediately after unhooking and held there until sale. Catches taken aboard the government alia were disposed of by Fisheries Division by public sale and those landed by the private vessel sold or consumed by the owner and his crew. All species taken, with the exception of sharks, found a ready market in Rarotonga and the catch was usually sold at the dockside for NZ$3/kg. 3.6 Data collection SPC Masterfishermen use a standard logsheet, (shown at Appendix 2), to record catch, effort and other data, and make detailed notes of their daily activities and of any supplementary information required. During this Project visit, data collected for each trip comprised: time spent travelling, anchoring and on each type of fishing; fishing depth or depth range; number of crew/trainees; quantity and type of fishing gear, fuel and bait used; the specific identity of each fish caught, where this could be determined; and the total number and weight of each species taken by each fishing method. 4. FISHING ACTIVITIES AND RESULTS 4.1 General The majority of the 34 fishing trips completed involved a combination of fishing methods, with trolling and deep-bottom handreeling the most common activities and together occupying 79 per cent of fishing time. These methods are complementary, in that trolling opportunistically while travelling to and from bottom-fishing sites may augment catches and provide fresh bottom-fishing bait with little or no increase in fuel consumption. Vertical longlining trials around Rarotonga's FADs were made during 6 trips and ika shibi fishing, bottom longlining and shallow-water handlining each conducted only once. 4.2 Deep-bottom handreeling Fishing at depths over 200 m along the outer reef-slope employing a baited multiple-hook terminal rig which is lowered and hauled by handreel while the fishing craft rests at anchor is the DSFD Project's standard fishing method and one which the Project has developed and refined during visits to 16 countries or territories in the SPC region. During this visit potential fishing sites were identified by observation of physical features and investigated further by echo-sounding, target depths ranging between 200 m and 500 m. Once a likely site was selected the anchor was dropped, when possible, in more shallow water and in a position selected so that prevailing wind and/or current would carry the boat back over the fishing site as the anchor warp was paid out. In calm conditions or when strong winds or currents ran parallel to the depth contours, it was necessary to anchor in the same depth as the fishing site or even in deeper water on occasion. Once the boat was resting at anchor fishing was conducted using the handreels and with a 1 kg or 2 kg sinker (depending on current strength) to take a terminal rig bearing three tuna circle hooks (Figure 6) to the bottom. Lines were thereafter kept taut by hand to allow fishermen to respond to bites by striking and to lessen the likelihood of fouling other lines. Because of the elasticity of the long lengths of line deployed much reliance is placed on the 'self-hooking' characteristic of the tuna circle hooks used. As it soon became apparent during these trips that local bottom species were generally of small size (averaging around 1 kg) the standard hook-size combination of No. 5, No. 6 and No. 7 was replaced with a smaller rig comprising No. 7, No. 8 and No. 9 Mustad tuna circle hooks.

16 10 Figure 6. Typical terminal rig for deep-bottom fishing Because no problems were experienced with sharks taking hooked fish, the lines were not hauled on the first or second strikes but left until it appeared that all baits had been struck. Fish were hauled as fast as practicable, making allowance for size, current strength and species, any one of which factors may place undue strain on the line. The best proven bait for deep-bottom fishing is fresh skipjack tuna (Katsuwonus pelamis) which was persistently difficult to obtain at Rarotonga, tuna of all species being scarce during the visit. The Project therefore purchased frozen New Zealand trevally locally and obtained supplies of Japanese saury from the longline fishery base in American Samoa. While these baits proved to be adequate and attracted strikes it is considered, based on experience elsewhere, that they were not as effective in producing catches as skipjack or other fresh tuna may have been. A simple technique was used to retrieve the anchor at the conclusion of fishing, or when changing fishing sites, which greatly reduced the effort required by hand hauling from depth. By motoring rapidly forward the pliable grapnel tines were bent and the anchor broken out, and then towed until it streamed behind the boat. While still under way the balloon buoy was clipped or shackled onto the anchor warp and released. Water resistance forced the buoy back along the warp until it was trapped by the 'no-return barb' whipped in place (refer Figure 5). The boat was then motored slowly back along the warp, which was fed inboard by hand, and the chain and anchor, suspended at the surface by the buoy, easily recovered. During the course of the early deep-bottom fishing trips it became apparent that the deep-bottom fish population was only thinly scattered around Rarotonga and that there were no noticeable concentrations of stocks around prominent features of the reef slope, as has been noted at other sites fished by the Project. It was therefore decided to experiment with drift fishing using a parachute seaanchor. The parachute sea-anchor was rigged with a 40 m length of 12 mm diameter floating line at the tripping point and a 10 m length of 6 mm diameter Kuralon line between the swivel and the boat (see Figure 7).

17 11 Figure 7. Parachute sea-anchor arrangement Once an area with favourable wind direction and of suitable depth was selected the parachute was deployed over the bow, with the outboard motor operator holding the boat into the wind. The boat was then reversed in the line of wind direction and the lines paid out until the parachute filled and arrested the boat's drift. Although terminal rigs and basic fishing techniques were similar to those used on a fixed anchor some care had to be exercised in deploying lines in order to avoid tangles. The best sequence proved to be to drop the forward lines first, as the boat's drift would stream these lines at an angle away from the boat. Once a forward line was hauled, it was rebaited and held until the corresponding stern reel was hauled, and only then re-dropped. Most fishing by this method was conducted in depths between 200 m and 400 m. The parachute sea-anchor proved to be effective and relatively simple to use so long as wind direction paralleled or blew slightly offshore of the line of the bottom contours, and it enabled fishing to be conducted in exposed areas where rough seas would have made fixed anchoring difficult or impossible. The most notable advantage was that the slow drift effected by the parachute allowed extensive areas of the bottom to be covered in search of scattered fish. Fishing depths ranged from 60 m to more than 500 m, but with most effort devoted to the 300 m to 400 m depth range, which proved to be the most consistently productive. The bottom slope at most areas around Rarotonga was found to be of moderate gradient and generally regular and the 300 m to 400 m bottom contour usually lay within 200 m to 300 m of the outer reef edge. A bottom relatively free of obstructions was also evident in the areas fished by drifting, as few incidents of fouling on the bottom occurred. Although catch records indicate that some areas produced a greater proportion of the catch than others there was no significant difference in catch rates from site to site and it is possible that these more productive areas (which are indicated in Figure 2) were simply easier to fish. A comparison of catch rates by the two different anchoring procedures indicates a higher return for drift fishing by parachute sea-anchor and, although a good deal more time was spent in fishing by this method, it would appear that the technique is that best suited to harvesting a scattered bottom population.

18 12 Table 2 summarises catch and effort for the saleable catch by the two methods. Table 2. Summary of catch and effort for the saleable catch taken during fixed anchoring and drifting under parachute sea-anchor Fishing Effort Catch Catch per unit Anchoring method hours (line/hours) No. Weight(kg) of effort (kg) Grapnel (fixed) Parachute (drifting) Bottom handreeling effort, by both anchoring methods, varied on each trip from a high of 11 fishing hours with 3 reels in use (33 reel hours) to a low of 1 fishing hour with 1 reel in use (1 reel hour), with a total effort accumulated of 296 reel hours. The catch of 595 fish with a combined weight of kg comprised 79 per cent of the kg taken by all fishing methods although deep-bottom handreeling occupied only 51 per cent of overall fishing hours. Only kg, or 14.1 per cent, of the bottom catch was unsaleable, comprising 2 sharks with a combined weight of 102 kg and an eel weighing 3.5 kg, which were given away. The catch rate for all species taken by deep-bottom handreeling was 2.4 kg per reel hour. This figure falls to 2.2 kg per reel hour when sharks are excluded from the catch and the figure stands when the only other unsaleable specie, an eel, is also excluded. The catch rate recorded during fishing from a fixed anchor, of 1.2 kg/reel hour, was 0.7 kg below that recorded by the same anchoring method during the Projects' 1982 visit, and the catch rate recorded during drift fishing under Parachute sea-anchor, at 2.4 kg/reel hour, was 0.5 kg better. The overall catch rate for marketable species only, of 2.2 kg/reel hour, is among the lowest recorded during Project operations in the SPC region and is comparable to the rate recorded at Funafuti in Tuvalu during 1976/77, the Project's first-ever country visit. Low productivity has been a consistent feature of the DSFD Project's deep-bottom fishing operations at Rarotonga and, as Table 3 indicates, this has been more a function of low individual fish size than low catch numbers. The deep-bottom catch included 27 different species, as detailed in Appendix 4a, more than twice the number of species recorded during the DSFD Project visit. As during the earlier visit, the short-tailed red snapper, Etelis carbunculus, was the most common species taken, with 361 individuals landed with a total weight of 330 kg, or 60.7 per cent of the total deep-bottom catch numerically and 44.2 per cent by weight. Although the catch of Etelis carbunculus was numerically very high in comparison with catches of this species taken elsewhere by the Project with a similar level of effort, the fish averaged only 0.9 kg in weight and the largest individual taken was 2.6 kg (this specimen was the only snapper landed which weighed more than 2 kg).

19 13 Table 3. Hook rates and catch rates by weight for the overall catch, excluding sharks,recorded by the DSFD Project at selected Pacific island locations Catch per unit of effort Location Year of visit Number/reel hours Weight/reel hours (kg) Vanuatu Truk (F.S.M.) Palau Fiji (Yasawa/ Mamanuca) Beveridge reef (Niue) Niue Kosrae (F.S.M.) Rarotonga Rarotonga (this visit) The second most important component of the catch was the cod Saloptia powelli which, though uncommon elsewhere in the region, at Rarotonga accounted for 16.2 per cent of the deep-bottom catch numerically and 13.5 per cent by weight. The only other species represented in significant proportion was the scorpion fish Pontinus macrocephalus, which comprised 7.7 per cent of this catch numerically and 7.8 per cent by weight. A notable feature of the catch was the absence of some of the more common deep-water snappers and jobfish usually associated with Etelis carbunculus, such as the ribbon-tailed red snapper Etelis coruscans, the yellow jobfish Pristipomoides flavippinis and the small-tooth jobfish Aphareus rutilans. Also notable was the large average size of the gold-tailed jobfish Pristipomoides auricilla and the banded flower snapper Pristipomoides zonatus. Large groupers of the species Epinephelus tuamotuensis were taken and these seemed to replace the curve-banded grouper Epinephelus morrhua recorded during the visit. But as these two species are similar in appearance, it is possible that E. tuamotuensis was wrongly identified as E. morrhua during the earlier visit. The catch of E. tuamotuensis, as well as the deep-water amberjack Seriola rivoliana included a number of individual specimens larger than 5.0 kg but the average size of fish taken in this catch (excluding sharks) was 1.1 kg, slightly smaller than the 1.3 kg average recorded in Trolling Most trolling was conducted opportunistically while travelling to and from, or between, bottom fishing sites. The standard wooden handreels were aligned toward the stern of the boat and the bottomfishing terminal rigs replaced with a variety of leader and lure sizes and types, depending on the species targeted. An Alvey Reefmaster handreel bearing 80 m of 77 kg test stainless steel monofilament wire, backed with 200 m of 130 kg test nylon monofilament, was also mounted as a sub-surface trolling line. The 80 m length of wire, when trolled, providing sufficient weight to hold the lure beneath the surface. Lines from the forward pair of reels were rigged through guides at the tip of the trolling booms (as described in Section 3.2) and passed through a ring attached to the end of a 'lazy-line' which led back into the boat, and which was used to haul the lines inboard for handling once a fish was hooked.

20 14 A variety of lure combinations were trolled, ranging from mm long feathers or artificial squids fitted with pearl-heads when fishing along the reef drop-off or around schools of small yellowfin or skipjack tunas, to 230 mm 300 mm long artificial squid lures when fishing offshore or specifically for wahoo (Acanthocybium solandri). Local troll fishermen take their best catches from the FADs deployed off the island, with the most productive time being from a half hour before, till just after, sunrise. Boat traffic around the FADs can become quite congested and competitive during this early morning period and the Project took care to avoid interfering with local fishermen's operations while attempting to evaluate the productivity of the FADs under different conditions and at different times of day. The most productive trolling presentation around the FADs proved to be a variety of small feathers and squids and one large lure trolled on the sub-surface line. Trolling along the reef drop-off was less productive, however the sub-surface line produced strikes much more often than the surface lines. The entire kg catch taken by trolling was saleable, and accounted for 20.5 per cent of the saleable catch by all methods. The 60 hours spent trolling, most often with 4 lines in use, recorded a catch of 3.0 kg per hour and a catch per unit of effort of 1.1 kg/line hour. The majority of the catch, by weight, was taken on the sub-surface wire line. The entire troll catch comprised only four species (see Appendix 3b), with wahoo (Acanthocybium solandri) and yellowfin tuna (Thunnus albacares) together accounting for 95.8 per cent of the total by weight. Of the four species taken, wahoo, yellowfin tuna and skipjack tuna are regarded as true pelagic types, and the bluefin trevally (Caranx melampygus) is associated with reef habitats. The species composition of this catch is detailed in Appendix 4b. 4.4 Vertical longlining Vertical longlining is a fishing technique presently under development by the DSFD Project and targets the deep-swimming tunas associated with FADs. The gear arrangement consisted of a mainline of 7 mm diameter 'Kuralon', or standard Japanese-type longline cord, and 15 snoods made up from 5.5 m lengths of 145 kg test nylon monofilament. Each snood was rigged with a snap-connector for attachment to the mainline and a No. 5, No. 4 or No. 3 Mustad tuna circle hook. Additional gear included two plastic longline floats and 2 kg and 4 kg lead sinkers. The mainline was coiled in a plastic fish box for storage and the snoods wound hook to eye on a plastic handcaster (see Figure 8). A vital component for successful fishing by this technique is an adequate supply of suitable bait. The most effective baits are considered to be fresh or iced mackerel scad (Decapterus spp.) and big-eye scad (Selar crumenophthalmus), known respectively in the Cook Islands as koperu and ature. Other baits may be used with some success, particularly fresh or frozen strips of tuna and flying fish. Frozen commercial baits such as Japanese saury or New Zealand trevally have also been used, but generally produce poorer catches. Previous trials with this gear in Niue (Mead, in press) relied on setting and holding the line close by a FAD. This was achieved by deploying the line from a dinghy and then tethering it, with the dinghy in turn moored to the FAD. At Rarotonga however, the Ministry of Marine Resources has broadcast a standing request that fishermen refrain from mooring to FADs except in emergencies, as it is thought that the extra strain of one or more fishing craft tied up to a FAD may contribute to failure of the FAD mooring system. The technique used during vertical longlining trials during this visit then, was to deploy the line up-current and allow it to drift past the FAD before hauling.

21 15 Figure 8. Vertical longline gear arrangement Current direction and speed were estimated by noting the disposition of the FAD appendages, which always align with the surface current, and the boat then run up-current in a direct line for 300 m to 800 m (depending on current speed). A 90 turn was then made, down wind if practicable, and the boat driven on this course for about 50 m. The vessel was then turned bow to wind and held in this attitude while the parachute sea-anchor was deployed over the bow. The parachute was tied off to the boat astern of the bow causing the alia to lie at a slight angle to the line of wind-driven drift. The longline could then be deployed over the stern, with setting time determined by the rate of drift and the efficiency of the crew. In ideal wind conditions (5 10 knots) the longline could be lowered quickly and without tangling, because the sinker held the line more or less vertically and the boat's drift caused the baited snoods to stream horizontally clear of the mainline. During setting the baited hooks were first placed overside and the snoods then clipped to the mainline at 15 m (8 fathom) intervals as the line was lowered. Once all snoods were attached a plastic longline float was clipped to the mainline, the line slacked off for 20 m and a second float attached. The line was then cast free of the boat. In winds over 5 knots the 'alias' rate of drift was usually much faster than the current-borne drift of the longline. The boat was allowed to drift until the longline floats were just out of sight and the parachute sea-anchor then hauled, the boat driven back up-current and the drifting procedure repeated. The longline was left untouched until it had drifted past the FAD and moved some 400 m to 800 m down-current, where it was picked up. To haul the longline efficiently, one crewman was required to hand in the mainline, one to unclip the snoods and land any hooked fish and one to hold the alia stern to wind by operating the outboard motor in reverse. If the line was to be reset, the snoods were

22 16 rebaited, the boat moved into position up-current as before (making any adjustments to position required by observing the line of drift of the first set), and the procedure repeated. A shortage of suitable bait during the early part of the Project's operations and a scarcity of tuna during the latter phase curtailed the projected effort in this fishing technique. The vertical longline was set during only 6 trips as a secondary fishing activity and results were poor. On the one occasion when the longline was set with suitable bait and tuna were in evidence around the FAD, two yellowfin tuna were taken, with a combined weight of 20.5 kg. 4.5 Deep-bottom longlining, ika shibi fishing and shallow-water handlining These three fishing techniques were conducted experimentally or opportunistically in conjunction with the Project's major fishing activities. An experimental deep-bottom longline was set three times during the first fishing trip made at Rarotonga. The line, bearing 30 tuna circle hooks and baited with skipjack, was set in depths ranging from 250 m to 350 m for a total of 2.5 hours soak time (7.5 hook hours). No bait were taken during the first two half-hour sets. On the third set, with a soak time of one and a half hours, all baits were taken but only one fish, a 1.0 kg Etelis carbunculus, was hooked (included in Appendix 3a). Ika shibi fishing, which involves mid-water handlining at night for tunas using an underwater light to attract baitfish to the vicinity and chumming (both of which attract tuna), was conducted during one trip. Baits were presented at depths between 20 m and 130 m and chumming conducted at minute intervals. Some baitfish and squid were observed around the underwater light but no tuna were sighted and no baits were struck. The scarcity of suitable bait and the apparently unseasonal scarcity of tunas, which hindered the vertical longlining trials, precluded further experimentation with this technique. Opportunistic shallow-water handlining was conducted during one trip in depths ranging between 20 and 40 m. Eighty-eight fish were taken during 12 line hours of effort, with a total weight of 22.5 kg. The species composition of this catch is detailed in Appendix 4c. 4.6 Catch and effort summary Table 4. Summary of catch of all species, and effort by each fishing method Effort Catch Catch per Fishing (reel line/ unit of Fishing method hours hook hours) No. Weight(kg) effort (kg) Bottom handreeling Trolling Shallow-water handlining Vertical longlining Bottom longlining Ika shibi fishing TOTAL A detailed account of catch and effort by each method during each trip is given in Appendix 3.

23 17 5. DISCUSSIONS AND RECOMMENDATIONS Of the three main fishing activities conducted during this visit, deep-bottom handreeling, trolling and vertical longlining, none was particularly productive, though each showed potential for development under certain circumstances, and each is considered worthy of further investigation. The report on the previous DSFD Project visit to Rarotonga (Taumaia and Preston, 1985) included a discussion of the likely economics of a small-scale deep-bottom fishery at the island, based on the catches recorded during that visit and on the then current costs of fuel and gear, boat loan repayments and fish market prices. The report concluded that a small-scale operator employing two crew aboard an alia catamaran purchased under loan would likely incur a loss of some NZ$ during the first year of operation. The experience of this Project visit indicates that, given the customary fishing habits and expertise of Rarotongan fishermen and the apparently impoverished deep-bottom resource, it is highly unlikely that any astute fishermen would attempt to base a commercial operation on this fishery alone. What is likely is that fishermen will adopt the simple and inexpensive gear and the proven techniques demonstrated by the Project to extend their range of fishing activities. Successful local fishermen are presently generally adept at trolling, bottom handlining, mid-water handlining for tuna by 'dropping stones', and flying fish scooping, and they practise whichever activity is seasonally most productive. The consistently high market value of the species generally taken by deep-bottom fishing, especially in light of the increasing, tourism-generated, demand for fine table fish by local restaurants and hotels, will make this fishery a valuable supplement to the commercial success of local fisheries endeavours. In addition, although the catch rate by this method was low and deep-bottom resources found to be only thinly distributed, the better part of the catch comprised valued species which commanded premium prices. Deep-bottom fishing grounds lie close to the island's harbours and are normally accessible to the fast 5 m - 6 m boats favoured by local artisanal fishermen. During normal trolling trips such boats typically pass over suitable deep-bottom fishing grounds. These boats are readily fitted with FAO-design wooden handreels and fishermen wishing to equip their craft to engage in supplementary deep-bottom fishing could do so at relatively little cost. The only major expenditure would be incurred by those purchasing a parachute sea-anchor, if this technique was favoured. The experience of the Project indicates that drift-fishing under such an anchor is the method best suited to exploiting the dispersed deep-bottom stocks at Rarotonga. Trolling lures and baits on a wire line so as to present them at depth proved to be a good deal more effective than the usual Rarotongan practice of trolling only surface lines. This technique, and other deep-trolling gear arrangements, are worthy of further investigation and development. Vertical longlining trials were hampered by a lack of suitable bait and an unseasonal scarcity of tunas as earlier discussed, but this technique has proved to be productive elsewhere, for example during DSFD Project visits to Niue in (Mead, in press) and American Samoa in 1988 (Moana, in press), and would seem a worthwhile technique to investigate further with a view to better exploiting Rarotonga's FADs. Small-scale commercial fishermen at Rarotonga could equip their boats to engage in these three fishing activities without substantial capital outlay and would likely maximise both their efficiency and their catches as they developed the techniques in ways best suited to local conditions. In view of the relatively meager near-shore fish resources noted at Rarotonga during this and previous visits, and in consideration of the seasonally large stocks of pelagic species which are reported to move through the area, and the strong and growing demand for fresh fish on the island, this report reiterates the recommendation made in the report on the Project visit, that the Cook Islands Ministry of Marine Resources devote its efforts in artisanal fisheries support to 'developing small-scale fishing techniques to enable the harvesting of fish associated with fish aggregation devices'. The success of the Cook Islands' FAD deployment programme in terms of increasing tuna fishing