UNPUBLISHED REPORT No. 27 REPORT ON FOURTH VISIT TONGA

Transcription

1 SOUTH PACIFIC COMMISSION UNPUBLISHED REPORT No. 27 REPORT ON FOURTH VISIT TO TONGA 27 April February 1986 by Paul Mead Masterfisherman and Lindsay Chapman South Pacific Commission Noumea, New Caledonia 1998

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 This unpublished report forms part of a series compiled by the Capture Section of the South Pacific Commission s Coastal Fisheries Programme.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. On 6 February 1998 the South Pacific Commission (SPC) became the Pacific Community. The Secretariat of the Pacific Community (retaining the acronym SPC) is now the name for the body which administers the work program of the Pacific Community. The names have changed, the organisation and the functions continue. This report was prepared when the organisation was called the South Pacific Commission, and that is the name used in it. Please note that any reference to the South Pacific Commission, could refer to what is now the Secretariat of the Pacific Community, or, less likely, to the Pacific Community itself. South Pacific Commission BP D Noumea Cedex New Caledonia Tel.: (687) Fax: (687) capture@spc.org.nc Prepared at South Pacific Commission headquarters, Noumea, New Caledonia, 1998

3 iii ACKNOWLEDGEMENTS The South Pacific Commission acknowledges the friendly assistance afforded the Masterfisherman by the many individuals associated with the Deep Sea Fisheries Development Project while in Tonga. Special thanks are due to Mr Semisi Fakahau, Principal Fisheries Officer for this considerable help in the organisation of the Project visit and his continuous personal support during the visit. Special thanks are due to all members of the Fisheries Extension staff, especially Mr Brian Hickson (Foundation for Peoples of the South Pacific), Mr Sione Kolo, Mr Nili, Mr Peter Hurrel, and Mr Luhama Fuapau for their personal assistance. The Project managed considerable productive hours at sea due to the enthusiastic support of the extension officer, fisherman and the boat owner/skipper Mr Naita Manu and his two very capable trainee crew Mr Viliami Tongo and Mr Kolipuna Lekaleka. Thanks are also due to members of the boatyard staff, engineering staff, and Fisheries and Agriculture Headquarters staff for their willing help and support.

4 v SUMMARY The South Pacific Commission's Deep Sea Fisheries Development Project operated in Tonga for seven months between 27 April 1985 and 8 February 1986, under the supervision of SPC Masterfisherman, Paul Mead. The main objective of the visit was to improve the effectiveness of small-scale fishing operations in Tongatapu, Ha'apai, and Vava'u. Secondary objectives included working with Tonga Fisheries Extension staff to improve their knowledge and application of new fishing techniques, to rig out a demonstration vessel, and to conduct a fishing survey of unfished seamounts. Sixteen fishing trips were completed during which seventeen local fishermen and eleven Fisheries Department staff participated in practical training at sea. A total of 1,335 fish with a landed weight of 7,901 kg were caught, primarily by deep reel bottom fishing. The overall deep bottom catch rates were 14.3 kg/reel/fishing-hour or 12.1 kg/reel/fishing-hour if dressed shark, which were all saleable at a reduced price, are excluded. The overall catch rates for the 32ft sail assisted demonstration vessel from which the majority of the work was carried out was an impressive 16.8 kg/reel/fishing-hour and 14.3 kg/reel/fishing-hour excluding dressed shark. These catch rates are the highest achieved by a DSFD Project operating in the South Pacific Commission region and were obtained mostly from the tops of lightly exploited seamounts in depths from metres. They are considerably higher than those achieved by the Project during its three earlier visits to Tonga. Tonga has a rapidly developing deep bottom fishery supported by the Tonga Fisheries Division. Nevertheless, considerable improvements, many of which are in progress, are needed in basic support infrastructure, fish handling, and marketing. This report hopefully recommends directions for future activities to promote development in these areas.

5 vii RÉSUMÉ Sous la direction du maître de pêche Paul Mead, les agents de la Commission du Pacifique Sud ont séjourné aux Tonga pendant sept mois, du 27 avril 1985 au 8 février 1986, dans le cadre du projet de développement de la pêche au demi-large. L'objectif principal de cette mission était d'améliorer l'efficacité des petites exploitations de pêche а Tongatapu, Ha'apai et Vava'u. Les objectifs annexes consistaient а collaborer avec les agents de vulgarisation des services de pêche de Tonga pour leur permettre de mieux connaître et utiliser de nouvelles techniques de pêche, à équiper un navire de démonstration et a tester les possibilités de pêche а proximité de monts sous-marins encore inexploités. Seize sorties ont été effectuées; elles ont permis à dix-sept pêcheurs locaux et à onze agents du service des pêches de recevoir une formation pratique en mer. Au total, poissons représentant un poids total de kg ont été capturés, essentiellement au moulinet et par grands fonds. Les prises d'ensemble par grands fonds ont été de 14,3 kg/moulinet/heure de pêche ou 12,1 kg/moulinet/heure de pêche si l'on exclut les requins parés, qui étaient tous vendables mais à prix réduit. Les taux de prises enregistrés par le navire de démonstration (navire de 32 pieds assisté d'une voile) sur lequel s'est effectué l'essentiel du travail, ont été impressionnants : 16,8 kg/moulinet/heure de pêche et 14,3 kg/moulinet/heure de pêche en excluant le requin paré. Ces taux de prises sont les plus impressionnants obtenus au cours des diverses campagnes menées dans le cadre du projet dans la zone d'action de la CPS, et ils ont été enregistrés principalement а la verticale des sommets de monts sous-marins où la pêche est peu pratiquée, et à des profondeurs allant de 200 à 400 mètres. Ils dépassent de loin ceux enregistrés par les agents du projet lors des trois précédentes missions aux Tonga. La pêche au grand fond se développe rapidement aux Tonga avec l'aide de la Division des pêches de ce pays. Il importe néanmoins d'apporter d'importantes améliorations (certaines sont déjà en cours) dans le domaine de l'infrastructure de soutien de base, de la manutention du poisson et de la commercialisation. Il est espéré que ce rapport permettra d'orienter les activités futures et de faire progresser la situation dans ces divers domaines.

6 ix CONTENTS Page 1. INTRODUCTION 1 2. BACKGROUND General Fisheries 3 3. PROJECT OPERATIONS General Boats and equipment Fishing techniques Training programme Handling and disposal of the catch Data collection RESULTS General Fishing areas Catch and effort by fishing method Deep-bottom fishing Trolling Species composition of the catch Catch by vessel Fishing economics CONCLUSIONS AND RECOMMENDATIONS Discussion and conclusions Recommendations 16 6 REFERENCES 17 APPENDICES 1. Summary of operational aspects of fishing trips 19 2a. Boats and equipment used in Project activities 21 2b. Basic equipment required for deep-bottom dropline fishing Topics covered in the Project training programme Standard form for data collection Seamount areas fished by the Project 29 6a. Species composition of bottom catch (excluding sharks) 31 6b. Species composition of bottom catch (sharks only) 35 6c. Species composition of troll catch 37

7 1 1. INTRODUCTION The South Pacific Commission's Deep Sea Fisheries Development (DSFD) Project is a mobile village-level rural development project which operates in Pacific Island nations at specific government request, and which has the following objectives: To promote the development or expansion, of artisanal fisheries throughout the region based on fishery resources which are at present under-utilised, and in particular the deep bottom resources of the outer reef slopes; 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 workers. This country visit is the fourth to Tonga since the DSFD Project commenced activities in The first two visits focussed on the demonstration of deep bottom fishing techniques using wooden handreels (Mead 1979, Mead 1980). The main aim of the third visit was to provide an evaluation of a number of different fishing vessel designs being built by a joint UNDP/Tonga Government boatbuilding project (Mead, 1987). The present Project visit followed a request from the Tongan government for assistance in improving the effectiveness of local small boat fishing activities and assessing the potential for their expansion and diversification. Specific objectives, to be undertaken in the Tongatapu, Ha'apai and Vava'u areas, were: To provide practical training in appropriate fishing methods to local fishermen and government personnel; To correctly rig out a demonstration vessel from which to carry out training activities; To encourage local fishermen to fish unexploited areas; and To provide a preliminary assessment of the deep bottom fishing potential of unexploited seamounts. In line with these objectives the Project operated in Tonga between 27 April 1985 and 8 February 1986, under the supervision of SPC Masterfisherman Paul Mead. Although the visit spanned a period of over 9 months, it was interrupted substantially on two occasions when the Masterfisherman travelled overseas to participate in other SPC activities. The two interruptions, together with the time taken for associated gear preparation and packing, totalled almost ten weeks, hence the time available for project work in Tonga was of the order of 7 months. 2. BACKGROUND 2.1 General Tonga, an independent Kingdom, comprises a widely dispersed group of 169 islands lying in a generally northnorth-easterly direction between latitudes 15 S and 24 S and longitudes 173 W and 175 W (Figure 1). The islands lie along a volcanically active ridge which also includes numerous seamounts, banks, and shoals, as well as active volcanoes. The country is divided into three main island groups, the Tongatapu group in the south on which is located the capital Nuku'alofa; the Ha'apai group, a scattered archipelago of mostly low coral islands and volcanoes in the centre; and Vava'u with its associated islands in the north. Pangai on the island of Lifuka is the administrative centre of the Ha'apai group and Neiafu located in the protected harbour of Port of Refuge on the island of Vava'u is the administrative centre of the Vava'u group. All three groups are associated with extensive ocean banks with depths of metres. In the deeper seas in between the outlying islands to the north and south of these three groups, as well as along the western side of the main island chain, are numerous seamounts and areas of submarine volcanic activity. Along the eastern side of the entire ridge the slope drops off quickly to depths over 1,000 fathoms. With a total land area of approximately 699 sq km the Kingdom's 200 mile exclusive economic zone (EEZ) would, if declared, encompass an area of approximately 677,021 sq km (SPC estimate). The shelf area, including seamounts, lying within the 100 fathom line was estimated at 1,550 square miles (4,014 sq km) (Anon, Fisheries Division Local Statistics file). In a census carried out in 1976, the

8 2 population was recorded as 90,085, of whom 18,312 were resident in Nuku'alofa (Navunisaravi and Naroba, 1985). Figure 1: Main islands and reef areas in Tonga

9 3 The climate of the group is mild with temperatures mostly between C in the warmer months of January to March and C in the cooler months of July to September. Relative humidity is usually higher in the warmer months (74 87%) than in the cooler months (60 84%). Average rainfall is also higher in summer ( mm per month) than in winter ( mm per month). Wind is from the east to southeast over 60% of the time throughout the year with more days of southerly winds in the cooler months. Average mean wind speed in early afternoon varies from 9 knots in the cooler months to knots in summer. 2.2 Fisheries As in most Pacific Islands, determining what percentage of the population are fishermen is difficult since most individuals over the age of two probably fish from time to time or collect seafood by one means or another. Slightly easier to quantify is the number of fishing vessels in a country: however there may still be substantial errors. In 1977 it was noted that there were 400 canoes, 250 outboard powered dinghies and inboard powered vessels comprising the Tongan fishing fleet (Thomas, 1978). Numbers supplied by Tonga Fisheries Division for publication in the SPC Fisheries Directory were 112 one-man canoes, 332 open boats and 15 motor launches (Crossland and Grandperrin, 1979). As the DSFD Project is concerned with artisanal fisheries mainly outside the barrier reefs this report will forego any comment on the many different types of inshore fishing methods employed in Tonga and will concern itself only with those aspects of fisheries and development which have direct relevance to the Project. Between 1975 and 1977 an exploratory bottom fishing and trolling project was carried out in Tonga by the Food and Agriculture Organisation of the United Nations (FAO) using American-manufactured snapper reels mounted on a 40 foot US-designed and built fibreglass multi-purpose vessel. Most bottom fishing from this vessel was in depths of less than 100 fathoms (184 m), mostly between fathoms ( m), on the larger banks associated with the main island groups. Fishing produced an overall bottom catch rate of 4.6 kg/reel-hour, the two main species landed being Lethrinus chrysostomus and Pristipomoides filamentosus (Thomas, 1978). Up until this time most bottom fishing by private boats outside the reef was by light handline in depths of less than 120 metres. Exact figures of boats engaged in bottom fishing and their landings during this period are at best broad estimates. Generally the size of boat used for bottom fishing was determined by factors such as distance of fishing grounds from home port and market, availability of ice, and the immediate financial situation of the boat owner. The greatest population concentration, and the only place where ice was available in any quantity, was Nuku'alofa, where the majority of the larger boats fished from and sold their catch in the capital. There were also numerous small open boats bottom fishing on day or overnight trips from Nuku'alofa and the Tongatapu area as well as Ha'apai and Vava'u. Due to the lack of basic infrastructure, finance, and marketing opportunities in other centres, only Nuku'alofa could support larger inboard fishing vessels. Thus the main bottom fishing area, which was under considerable fishing pressure, was the region of large shallow banks to the north of Tongatapu. Between 3 June and 20 September 1978 the South Pacific Commission's DSFD Project operated in Tonga working from both Fisheries Division and private boats and fishing depths down to 200 fathoms (366 m). In the earlier Project report (Mead, 1979) it was noted that Tonga probably has as many or more seamounts than any other South Pacific country. Due to the interest in deep water snapper fishing generated by the first visit, the Project returned to Tonga in 1979 for three months and in for 8 months. The 1979 visit was concerned mainly with further training of selected Fisheries Division personnel in deep water snapper fishing techniques (Mead, 1980). The main aim of the lengthier Project visit in was to examine the suitability and effectiveness of various prototype sailing and motor-sailing craft being produced by the FAO-UNDP boat building project in Tonga (Mead, 1987). The FAO bottom-fishing project, and the subsequent SPC-DSFD Project visits, effectively demonstrated the high catch potential of deep bottom fishing. These trials were carried out against a background of increasing fishing pressure in inshore waters, and an increasing local demand for fresh fish (in 1984 the projected minimal level of demand for fresh fish in Tonga for the year 1987 was estimated to be around 5,250 tonnes (Elsy, 1984)). As a result, the Tonga Fisheries Division, with FAO/UNDP assistance, embarked on a programme of expanding its boat building capabilities, with the stated objective of putting into operation a total of 60 artisanal fishing boats by the end of Under the UNCDF boat building scheme, fishermen are able to Lethrinus chrysostomus and Pristipomoides filamentosus are incorrectly identified in the report as Lethrinus lentjan and Pristipomoides typus.

10 4 purchase 20 32ft (6 10 m) fishing vessels at a subsidised rate, which essentially covers the cost of materials and labour used in the vessels construction. The engine, as well as a variety of deck equipment and fishing gear, are provided free under a grant-in-aid programme of the government of Japan (Cartwright, 1984). Through programmes of demonstration and training, coupled with financial aid to fishermen, deep bottom fishing using wooden handreels is now being encouraged and carried out on outer reef slopes, banks, and seamounts throughout the Kingdom. There are 20 of the UNCDF boats in the water (see Table 1), many of them concentrating on bottom fishing in depths greater than 120 metres and down to 400 metres. Deep bottom species are now regularly offered for sale in the main centres on 'Eua, Tongatapu, Ha'apai and Vava'u. Table 1: Location and numbers of UNCDF boats in Tonga Location Number of boats Size of boats 'Eua 3 20ft (6 m) Tongatapu 3 28ft (8.4 m) 1 32ft (9.6 m) 1 20ft (6 m) Ha'apai 1 28ft (8.4 m) 4 20ft (6 m) Vava'u 7 28ft (8.4 m) 3. PROJECT OPERATIONS 3.1 General 20 The Masterfisherman arrived in Tonga on 27 April 1985 and left on 10 February In all phases of the Project the Masterfisherman worked closely with the Principal Fisheries Officer of the Tongan Fisheries Division, Mr Semisi Fakahau and Fisheries Division extension staff, in both planning and implementation of all Project activities. Table 2 gives a summary of Project activities during this period. Gear shipped by air and sea was cleared from customs on 4 May and moved to government housing but not immediately unpacked as the Masterfisherman assisted FAO marketing consultant, Mr Richard Elsy, and Fisheries Division personnel in catching, onboard handling and packing a trial air shipment of fresh whole fish to be sent to the Hawaii auction market. For this shipment fish were caught by handline from the Fisheries vessel "Albacore" on a trip which commenced on 6 May and returned on 10 May (trip 1 in Appendix 1). The trip was organised by the FAO consultant and Fisheries Division personnel, with management of vessel, gear, crew, selection of fishing ground, etc., being the responsibility of the boat skipper and Fisheries Extension Officers. The SPC Masterfisherman's responsibilities were the demonstration of onboard fish handling techniques for fresh (export-quality) fish, and record-keeping. Upon returning to port the Masterfisherman assisted in onshore care and packing of the catch. After the conclusion of this exercise the next two weeks were occupied by unpacking, cleaning and assembling gear, construction of anchors and boat equipment, and preparing fishing gear for work in Tonga and for the forthcoming SPC/Nelson Polytechnic Pacific Fisheries Officers course. In the 11 weeks between 1 July 1985 and 14 August 1985 the Masterfisherman was absent from Tonga for a total of 8 weeks, firstly for the SPC/Nelson Polytechnic Pacific Fisheries Officers course in Fiji, and secondly for the 17th SPC Regional Technical Meeting on Fisheries in Noumea. Project time before and after each of these trips was lost due to packing and unpacking, clearing gear from customs and the need to dismantle and re-rig fishing equipment. Other activities carried out during this period included cleaning the hull and carrying out engine repairs to the Fisheries division vessel "Vete" in preparation for its use by the Project. Subsequently a short trip to the Ha'apai Group between 23 and 27 July resulted in the three day trips designated 2, 3 and 4 in Appendix 1. These three trips were aboard a 20ft (6 m) training vessel operated by the Ha'apai Fisheries Division, and were carried out mainly to enable the Masterfisherman to make practical suggestions on the placement of fishing gear and the onboard organisation of the vessels equipment.

11 5 Table 2: Summary of activities 27 April 1985 Arrived in Tonga. 29 Apr. 04 May Cleared gear from customs, planning of activities. 06 May 10 May Fishing aboard "Albacore", trial shipment of fresh fish to Hawaii. 13 May 24 May Unpacking, cleaning, and assembling gear. Rigged anchors, sinkers, terminal rigs. 27 May 31 May Rigging and packing gear to take to Fiji for the SPC/Nelson Polytechnic Pacific Fisheries Officer course. 01 Jun. 13 Jul. Fiji for the SPC/Nelson Polytechnic Pacific Fisheries Officer course. 15 Jul. 16 Jul. Cleared gear from customs. 17 Jul. 22 Jul. Cleaning and engine repairs to "Vete", a 26ft (7.8 m) mini-longliner. 23 Jul. 27 Jul. Ha'apai fishing trip. 29 Jul. 31 Jul. Preparations for SPC technical meeting. 01 Aug. 14 Aug. SPC technical meeting in Noumea. 19 Aug. 10 Sept. Customs clearance on gear from Noumea, unpacking, cleaning gear, rigging out "Vete" and 32ft (9.6 m) sailassisted vessel. 11 Sep. 20 Sep. Familiarisation trips aboard "Vete". 23 Sep. 20 Dec. Ten extended fishing trips aboard 32ft (9.6 m) vessel. 23 Dec. 03 Jan.1986 Government Christmas and New Year's holidays. 04 Jan. 08 Feb. Write up and packing. 10 Feb. Departed from Tonga. From the middle of August until the middle of September the "Vete" was rigged for trolling and two trips completed (5 and 6). During this period considerable time was also spent helping to rig a 32ft (9.6 m) sailassisted boat belonging to Mr Naita Manu, formerly a Fisheries Division Extension Officer who had recently purchased his own vessel under the UNCDF scheme. Mr Manu and his vessel were under contract to the Fisheries Division to carry out training and survey work under the Masterfisherman's supervision. From 25 September until 15 December ten trips were attempted and 9 completed (7 16) by this vessel with one trip (trip 9) being abandoned due to worsening weather conditions. These trips concentrated on providing training for fishermen who had applied to buy boats under the UNCDF scheme, and on a survey of "new" bottom fishing areas. Christmas and New Year's celebrations and holidays occupied the last two weeks of Most of January was spent cleaning and packing gear, discussions with local fishermen, and report writing. 3.2 Boats and equipment As noted in Section 3.1, four different vessels were used at different stages of the Project. These were: the "Albacore", a diesel-powered fibreglass mini purse-seiner, used on the first trip only to provide fish samples for export marketing trials; a 20ft (6 m) sail-assisted diesel-powered wooden open boat operated as a training vessel by the Ha'apai Fisheries Division. Three one-day trips were made on this vessel, mainly so that the Masterfisherman could advise on fishing organisation and deck layout; the "Vete", a diesel-powered fibreglass mini-longliner. Two trips were made from this boat; and a 32ft (9.6 m) sail-assisted diesel-powered wooden fishing boat belonging to a private owner, Mr Naitu Manu, who was under contract to the Fisheries Division to carry out training and extension work. The bulk of the Project's work was carried out aboard this vessel during 10 extended fishing trips. Further details of the vessels and their deck equipment can be found at Appendix 2a. The fishing gear and equipment on board each vessel depended on the vessel itself and on the objectives of the trip. Deep bottom fishing was the main fishing method carried out, and, except on the "Albacore", where

12 6 handlines were used, the fishing equipment for this method included the wooden handreels and terminal rigs shown in Figures 2 and 3. Subsurface trolling was the secondary fishing method practised, and for this two commercially made 'Alvey' fishing reels were used in conjunction with an assortment of lines and lures which are described more fully in Section 3.3. Other fishing gear carried at all times included a selection of spare hooks, swivels, lines and sinkers, plus various knives, bait boards, gaffs and ropes as listed in Appendix 2b. Figure 2: Wooden handreels Figure 3: Typical terminal rig for deep-bottom fishing

13 7 Additional to the fishing equipment, an echo-sounder was used for locating suitable bottom fishing depths and seabed profiles. On vessels which did not have an echo-sounder permanently installed, the Project's portable JMC-707 battery-powered echo-sounder, with a range to 420 m, was used. All vessels were equipped with suitable anchoring gear for deep-bottom fishing as illustrated in Figure 4. This comprised: a simply constructed grapnel anchor made of four 1.5 m (approximately) lengths of 3/8 inch (9 mm) reinforcing bar, welded together and bent into a grapnel shape; a 5 m length of ½ inch (12 mm) chain shackled to the anchor; approximately 440 m of polypropylene anchor rope, of a diameter appropriate to the size of the vessel (generally 12 mm), and fitted with a "no-return" barb made of 4 mm galvanised fence wire; and an inflatable buoy of 75 kg or greater flotation, fitted with a snap shackle or short rope eye which could be loosely clipped or shackled to the anchor rope so as to slide freely along it. 3.3 Fishing techniques Figure 4: Anchoring gear for deep-bottom fishing The main fishing methods used by the Project were bottom fishing using wooden handreels, and subsurface trolling using two Australian manufactured Alvey reels. Most bottom fishing was carried out from an anchored position using the Project's standard anchoring techniques. The use of a parachute anchor for bottom fishing was also demonstrated. To effectively locate and work the seamount areas around Tonga basic coastal navigation equipment was essential. This equipment consisted of appropriate navigational charts, parallel rule, dividers, pencil, compass and watch. An echo sounder capable of recording depths to at least 300 metres is also essential, and a capability of 800 metres or greater would be a considerable advantage. After observing the wind and sea conditions, a seamount would be selected from the chart, and the compass course and distance noted. Once the boat was underway lures were towed from the two Alvey reels at a distance of 80 to 100 metres behind the boat in order to catch fish on the way to the seamount. Even if schools of tuna or other pelagic species were sighted they were generally not trolled unless in the direct path of the vessel, as the compass course was strictly adhered to. The two Alvey reels, although mechanically alike, had different diameters. The largest (Reef King') was rigged with 300 metres of 150 kg Japanese 'super-toto' line while the smaller reel (Reef Master), was rigged with 300 metres of 50 kg test line. The 'super-toto' was essentially used as backing, and on both reels was attached by a 300 lb (136 kg) test Sampo ballbearing swivel to metres of 275 lb (125 kg) test 49-strand stainless steel wire. This was attached by another Sampo swivel of the same size to 30 metres of 113 kg test monofilament line on the larger reel and the same length of 45 kg test monofilament line on the smaller reel. These monofilament lines terminated respectively with 300 lb (136 kg) test and 150 lb (68 kg) test Sampo snap swivels to which the lures were snapped on. The sizes of lures varied considerably from area to area, time of day, sea conditions, and what type of fish were expected. After the lure was attached it was let out behind the boat until the entire length of cable was in the water. The tension on the reel's star drag was then set to match the strength of the leader used on the lure. On strikes by large fish up to 200 metres of line could be pulled off on one run. By using the drag system there is never anything solid for big fish to pull against and break off and it is therefore possible, by

14 8 being patient, to land most larger fish. The largest trolled fish landed by the Project in Tonga weighed 76 kg, which if sold on the Nuku'alofa market at $2.00 per kg would have raised more than enough to cover all bait and fuel costs for an average trip. Trolling to and from bottom fishing areas is an important part of operating a bottom fishing boat in Tonga, with the dollar value of the troll catch often being equal to the fuel cost of the trip. Upon locating bottom on the sounder, the course was continued across the area as long as the recording chart of the sounder showed the bottom to be rising. Once the depth showed a definite downward trend the boat was immediately turned around and run back along a reciprocal course until the highest point previously recorded was reached. At this point a course was run at a right angle to the first course until a distinct rise or fall in the bottom slope was observed. If the bottom was rising this course was followed until the depth began to fall away. The reciprocal course was again run until the highest point reached and then another right angle course run off this point. This method was continued until the highest point of the bottom (shallowest depth) was located at which time the anchor was lowered. The anchor rope was slacked off until it was determined by the Masterfisherman and skipper that there was enough scope to prevent the anchor being pulled out. Generally this was around 2:1 depending on sea conditions: in quieter seas the initial scope would be less while in rough seas it would be greater. Once the anchor was observed to be holding fishing would commence. Bottom fishing was by the use of the wooden handreels (Figure 2) fitted with metres of kg test monofilament nylon line attached by a no. 4/0 snap swivel to a wire terminal rig (Figure 3) with a 1 2 kg sinker. The technique for using this rig was essentially the same as has been described in previous Deep Sea Fisheries Development Project reports. After lowering the sinker to the bottom the line was kept tight by hand, allowing the fisherman to respond quickly to bites by striking, and to reduce the possibility of tangling with other lines. Due to the large size of many of the fish, and the possibility of shark attack, hooked fish were hauled immediately. Fish were hauled as quickly as possible, hauling rate varying according to their size. Smaller fish were hauled rapidly straight to the surface while larger fish were played according to their strength, to avoid loss caused by the mouth tearing or the hook straightening. Due to its firmness on the hook and its capacity to attract bottom fish, fresh skipjack is regarded as the best bottom fishing bait. However it was never available during the Project's stay in Tonga, and an adequate substitute, frozen saury (Japanese longline bait), was used. Several characteristics of saury contribute to its effectiveness as a bottom fish bait: it has a high oil content and strong smell; it freezes well; it is well packaged and easy to store; and individual fish are of a handy size, each fish being sufficient for 2 4 bait pieces when cut straight across, with very little waste. On the 32ft (9.6 m) private vessel used for trips 7 16, 2 3 standard 10 kg cartons were used per trip, price per carton to the fisherman being T$ Having adequate bait supplies readily available enabled more trip time to be spent on bottom fishing, resulting in a more favourable ratio of bottom fishing time to steaming time. As most of the seamounts fished were in the open sea out of visual range of land, weather conditions were monitored carefully when trips were being planned. Trips were attempted only when the weather forecast was for slight or slight-to-moderate seas and observed wind speeds were below 15 knots. Currents over the seamount areas were strong at times, generally in a westerly direction but often at a slight angle to the wind, which caused the boat to roll considerably at anchor. Bottom fishing was carried out on a round-the-clock basis, fishing time being influenced by how much rest fishermen had before arriving at the seamount, sea conditions, weather conditions, strength of the current, strength of the sun, etc. A few generalisations were: consistently productive fishing hours for Etelis spp. were from 15:30 19:00 although at times fish bit throughout the day or night; bottom fishing in shallower depths (less than 160 m) was more productive at night, late afternoon, or early morning; all the gempylids caught were landed between sunset and sunrise; and the deeper the top of a mount or peak the fewer species landed by the gear used. The fishing anchor used by the Project was a simple grapnel, made from 10mm steel bar, as shown in Figure 4. A simple technique was used to retrieve the anchor after fishing, greatly reducing the effort involved in hauling (Figure 5). By motoring rapidly forward after the anchor was broken free from the bottom, the anchor was towed until it streamed on the surface behind the boat. Still under-way, a free running buoy shackled on the line and released and forced back along the rope until it was seen or felt to catch on the anchor. At this time the boat was stopped and the buoy trapped by a "no return" wire barbed whipped onto the line (Figure 4). The anchor and chain thus remained suspended by the buoy at the sea surface. The boat could then be motored slowly back up the floating anchor rope to the buoy and suspended anchor, hauling in the anchor rope until the buoy was recovered.

15 9 3.4 Training programme A total of 23 fishermen made one or more sea trips with the Masterfisherman. These included 11 private fishermen and 12 staff of the Tonga Fisheries Division, of whom 4 were extension officers. During the trips the fishermen received practical instructions in deep-bottom fishing and aspects of small-boat seamanship, safety at sea, and the preparation and care of fishing gear. This was reinforced in on-shore sessions before and after fishing trips, during which related topics, such as the use of marine charts, and the proper handling of the catch, were also covered. Details of the training programme subjects are shown in Appendix 3. An especially successful part of the training programme was that involving Mr Naita Manu and the UNCDF 32ft (9.6 m) sail-assisted vessel being purchased by him. Mr Manu was assigned as the Masterfisherman's counterpart, and his vessel, through a special arrangement with the Fisheries Division, used as a demonstrationtraining vessel. This arrangement gave Mr Manu all proceeds from fish sales but made him responsible for all running costs and expenses. Thirteen different participants spent sea time aboard this vessel during the 10 fishing-training trips. Mr Manu proved to be a competent seaman, boat skipper and fisherman, as well as an above average extension officer. Two of the trainee fishermen who participated in the trips, Mr Viliami Tongo and Mr Kolipuna Lekaleka, also proved to be hardworking fishermen of above average ability. On the completion of the DSFD Project visit it was planned that Mr Manu would continue the training programme both for present boat owner-fishermen and for future hopefuls. Figure 5: Anchor retrieval method

16 10 The Masterfisherman also participated in a two week training programme organised and managed by Fisheries Division extension staff and Mr Brian Hickson of the Foundation for the People of the South Pacific. This programme was for selected individuals who had applied to buy boats under the UNCDF scheme. Subjects covered included care and use of electronic equipment (including echo sounder and VHF radio), financial management, coastal navigation, vessel care and maintenance, boat construction methods and materials, and fishing methods. The Masterfisherman participated in the sessions on fishing methods, gear types, and rigging of gear. 3.5 Handling and disposal of the catch Fish caught with Project assistance or under Project supervision were for two different markets. Most were sold locally, while a selected portion of the catch from the first trip was air freighted to the Hawaii market. As in most fish marketing situations the demands of the market dictated the handling practices used. Species of fish suitable for export caught from the Fisheries Division's vessel Albacore were handled differently and packed separately from those for the local market. On landing, fish with export potential were carefully unhooked by the Masterfisherman or one of the two extension staff, Mr Manu or Mr Kolo, and killed by spiking through the brain. This was accomplished by inserting a sharp stainless steel spike underneath the upper portion of the gill cover forward into the brain, the fish was then packed whole, belly down, in crushed ice carried in an insulated deck box of approximately 0.5 cubic metre capacity. Fish for the local market were held in a built-in insulated fish hold. Care was taken when packing the export fish to ensure that there was sufficient ice between each fish to prevent fish-to-fish contact which could cause discoloration. They were held this way in the well-drained box until the vessel arrived back in port the day before the scheduled departure of the plane for Hawaii. Prior to packing, the fish were unloaded from the boat, placed in crushed ice inside insulated 6ft (1.8 m) long Hawaiian "Ice-n-Brine" bags, and taken from the vessel to Fisheries Division Headquarters. As flight time was in the early morning, fish were packed the night before and held in a cold store at O C until loading time. They were held in the insulated bags until a few hours before packing time when just enough salt-water was added to the bags to form an ice/brine slurry. Fish were left in the slurry for approximately two hours, then removed, dried, and placed in plastic bags. Each bag was wrapped in newspaper, then packed carefully in a cardboard box lined with plastic and more newspaper and the box taped shut. The cardboard boxes were held inside the Fisheries Freezer at O C until loading time the next morning. It was reported that the fish arrived in Hawaii in excellent condition and brought top prices at the fish auction. Fish sold on the Tongan market were packed and iced whole in the boats' insulated boxes or holds as soon as possible after landing. They were kept well iced until the boat returned to port. Off the private boat they were usually unloaded 100 kg at a time and sold in the public open-air market by Mr Manu and family. At the market Mr Manu's fish were displayed in plastic fish boxes partially covered in ice, as opposed to the local practice of simply laying the fish out dry on a wooden platform and leaving it there without cooling until sold, sometimes for the entire day. Fish over 10 kg and dressed shark were cut into 2 5 kg chunks for sale while smaller fish were sold whole. Shark is readily acceptable as a lower quality food fish in Tonga and sold at T$0.50/kg while other fish usually brought T$1.40 T$2.00, depending more on supply and demand than on species or quality. Species of Gempylidae such as the oilfish (Ruvettus pretiosus) usually sold at the same price as high quality snapper type fish. However the snapper type fish most often sold first, the lower quality species being sold when snapper types were not available. On the two occasions when the market seemed to be flooded the entire catch was sold to a local entrepreneur for T$1.40 T$I.70/kg. Because of the above average care both on board and while marketing, Mr Manu quickly gained a reputation for having "fresh" fish and his catch was always the first choice of regular customers. 3.6 Data collection Detailed records of all fishing trips were maintained by the Masterfisherman using the standard SPC data forms shown at Appendix 4. Information gathered on each trip included: time spent steaming, trolling, and bottom fishing; fishing area; depth range when bottom fishing; number of crew; quantity and type of fuel and bait used; the identity of each fish caught where this could be determined; and the total number and weight (kg) of each species. All fish were identified and weighed whole when possible before they were packed in ice aboard the vessel. If because of rough sea conditions, rain, or limited assistance this was not possible, they were identified and weighed as they were unloaded at the wharf. If some doubt existed to the identity of a species a specimen was kept by the Masterfisherman to be examined in more detail and keyed out at a more convenient time. Most fish

17 11 of questionable identification were photographed and the photos sent to an appropriate specialist for identification. 4. RESULTS 4.1 General Sixteen fishing trips were completed from four different vessels during the Project visit to Tonga, with a total of 779 hours being spent at sea. Fishing was carried out principally by deep-bottom fishing using lines and wooden handreels, and secondarily by trolling, over a wide range of areas. The total catch from the fishing operations was 7,901 kg, of which 7,477 (95%) was caught by deep-bottom fishing. The mean catch per trip was thus kg, comprising on average kg of bottom fish, 71.5 kg of shark, and 26.5 kg of trolled fish. Full details of the catches obtained on each trip can be found in Appendix Fishing areas Figure 6 shows the main steaming routes and areas fished by the four different vessels used by the Project. Figure 6: Areas fished by the four different vessels during the Project Areas bottom fished by the "Albacore" were: metres depths over two small unproductive seamounts off the ENE coast of Tongatapu and to the west of 'Euaiki and 'Eua; metre depths along the northeastern edge of the large shallow bank immediately north of Tongatapu; and metre depths on two small ridges off the south-eastern lip of the Hunga crater. The entire area covered by light trolling rigs by the 20ft Ha'apai boat was within 20 miles of Pangai mostly to the west. This is an area of reefs, small islands, and "deep holes", protected to the east by a barrier reef but partially open to the west. On a day of westerly winds both light rig trolling and bottom fishing were undertaken along the eastern edge of the barrier reef to the east of Uoleva and Lifuka islands. However, persistent easterlies usually limit bottom fishing along this productive area.

18 12 The area fished by the "Vete", using mostly heavy trolling rigs, was from Duff reef off western Tongatapu, along western and southern Tongatapu to 'Eua, all the way around 'Eua to 'Euaiki and back to Nuku'alofa from the east through Piha passage. Concentrating mostly on bottom fishing, the private vessel logged more than 1,500 nautical miles (2,780 km) on fishing trips from Ata in the South to Vava'u in the north, a linear distance of over 250 miles (400 km). Bottom fishing was in depths from m, with trolling using 1 3 lines being carried out in daylight hours whenever the boat was moving. A very productive area with numerous seamounts was fished to the west and southwest of Tongatapu all within 20 miles of the island. Several seamounts were investigated south of 'Eua and one which rose to a gradual point with a depth of 200 metres was fished with good results. The north end of Fonuafo'ou was thoroughly investigated with the echo sounder and provided productive fishing in depths from metres. Other areas fished were along the lee shores of the volcanic islands of Kao and Tofua and two extremely productive seamounts in between the Ha'apai and Vava'u groups. Appendix 5 gives a description of several of these seamount areas with approximate positions and depths fished. The echo sounder was monitored most of the time when the boat was moving resulting in several seamounts being located which are not on the present admiralty charts. 4.3 Catch and effort by fishing method Deep-bottom fishing The total catch by all fishing methods during the Project visit was 7,901 kg, of which 7,477 kg were caught by deep-bottom fishing (6,333 kg of bottom fish and 1,144 kg of dressed shark). Catch rates varied substantially between the four different vessels used (see section 4.5) due to differences in the vessels' fishing arrangements, the trip objectives, and the areas fished. Overall, however, catch rates were excellent. The number of handreels (or, on the "Albacore", handlines) in use varied from 2 4, and over a total of 177 hours spent fishing, generated a fishing effort of 523 line-hours. The overall catch rate was therefore 42.2 kg/fishing-hour, or 14.3 kg/linehour. If sharks are excluded from the catch, the values are reduced to 35.8 kg/fishing-hour and 12.1 kg/line-hour respectively. As shown in Table 3, these catch rates are among the highest yet achieved by any DSFD Project visit. Table 3: Deep-bottom catch rates obtained by the Deep Sea Fisheries Development Project in selected Pacific locations Country Year of visit Bottom reel catch rate (kg/line/hour) Total Excluding sharks Tokelau Cook Islands: Rarotonga Penrhyn American Samoa Wallis and Futuna Tuvalu Kiribati Federated States of Micronesia: Kosrae Truk Palau Fiji (Western Division) (Northern Division) Tonga Trolling Trolling from all vessels occupied 131 hours and produced a catch of 72 fish with a total weight of 424 kg, all of which was marketable. Except for the first trip of the "Vete" (trip 5) trolling was on an opportune basis only, usually between the bottom fishing area and port. Lures were trolled on 1 4 lines, the number of lines depending on the vessel used, time of day, and existing sea conditions. Generally 2 3 lines were trolled from the "Albacore", 2 4 from the "Vete", 2 from the Ha'apai boat, and 1 3 from the private vessel. Total line hours for all four vessels was 287 producing an overall CPUE of 1.5 kg/line-hour. The CPUE varied from a high of 2.2 kg for 20 hours of effort on the Ha'apai boat to a low of 0 for 28 hours of effort on the "Albacore". These troll rates are what can be expected when trolling is conducted on an opportune basis when travelling from one

19 13 area to another. They do not reflect what could be expected from a boat organised and equipped specifically for trolling and able to take advantage of school trolling and reef trolling opportunities. General observations made while trolling from the different vessels were that the "Albacore's" system of heavy surface lines with large lures on heavy wire leaders towed at over 9 knots along reefs and across shallow banks caught very little, while small lures rigged on light wire traces, trolled on light lines at 4 6 knots in the same types of area, caught fish consistently. Any time a vessel is moving during daylight hours troll lines should be towed and carefully watched. 4.4 Species composition of the catch Catches by all fishing methods produced 1,335 fish and shark weighing 7,901 kg and comprising 65 species from 17 different families. Bottom reel fishing produced 7,477 kg or 94.5% of the total. Among the bottom reel catch, deep water snappers of the family Etelidae were the dominant group comprising 73.2% by numbers and 45.9% by weight. Of the Etelidae two species, Etelis carbunculus and Etelis coruscans contributed 14% and 20% respectively to the total bottom catch weight. Numerically Etelis coruscans was the most prevalent species with 469 fish making up 37% of the bottom catch by number. Second in importance were fishes of the family Serranidae (24.1% by weight, 12.8% by number), dominated by the species Epinephelus septemfasciatus which accounted for 22% by weight of the total deep bottom catch. Sharks from four different families made up 15.3% by weight of the bottom catch. A feature of the shark catch was the high percentage of oceanic species. The only other family of fish which contributed significantly to the bottom catch was the Gempylidae (8.2% by weight) represented by three species of which Ruvettus pretiosus (7.6% by weight) was the principal. Figure 7 shows the relative proportions of the major families or species groups in the deep-bottom catch. More details of the catch composition can be found at Appendix 6. Figure 7: Major families or species groups in the deep-bottom catch The three deep-bottom species which dominated the bottom catch, Etelis carbunculus, E. coruscans and Epinephelus septemfasciatus (total 57.2% by weight) were caught off seamounts, mostly in depths of 260 to 440 metres with Etelis coruscans generally dominating in the shallower parts of this scale and Etelis carbunculus at the deeper end Epinephelus septemfasciatus was caught fairly consistently throughout this range with no noticeable size variation with depth. Despite the considerable number of small (1 5 kg) individuals in the catch, the average weight for Etelis carbunculus (8.6 kg) and Epinephelus septemfasciatus (18.3 kg) were higher than the usual average weights of these species in other areas of the region. The average weight of Etelis coruscans (3 4 kg) was less than that for the region (approximately 5.0 kg). A good number of Etelis carbunculus with individual weights over 20 kg were landed, the largest being 32 kg. Over 15 Epinephelus septemfasciatus in excess of 40 kg were also landed. On one occasion (trip 16) when the boat was anchored on a seamount which came to a definite peak at 220 metres, a large number (69) of Pristipomoides filamentosus were caught with an average weight of 3.7 kg. Fishing seamounts also produced two species which the Masterfisherman had not caught previously; from the seamount south of 'Eua in metres 3 individuals of a carangid, possibly Seriola lalandi, were landed; and from a seamount west of Tongatapu in depths of m three individuals of an emmelichthyid, probably Erythrocles sp., averaging 4 kg each were landed. The troll catch was composed of 19 different species from 8 different families, of which the tunas and mackerels of the family Scombridae, dominated the catch both in numbers (50%) and in weight (48%). A feature of the troll catch was the great variety of species and families represented and the absence of a small number of