The early attempts on rearing larvae to settlement have been mainly conducted in the Japanese research institutes (Yamanaka et al., 1960,) and the knowledge and expertise have been handed down to the private sectors. Although the production has been increasing, the success rate is still less than 1% from larval stage to the settlement. It should be noted that the larvae had been fed with Monocrysis sp. and Dunaliella terteolecta at that time, which is now considered to be insufficient micro-algae species as food for the larval rearing of pearl oysters. The success rate from onset of the larval rearing to the settlement is between 15 and 30% after selection processes of larvae in hatchery operations (Ito, 1992, 1998a; Ito et.al., 1995;). When the spat reach to 3–5mm in shell length, they are transferred from land-based tank culture to cage/net protected with mesh screen (1–2mm) for ocean nursery culture. After one year nursery culture the spat reached around 50–60mm in shell length, and those of shell length, 120–150mm is the operable size for seeding (nucleus implantation). During this culture period, the major maintenance work involves culture cage/net change and size selection, culture density adjustment, and shell cleaning, which are conducted 2–3 times a year; 1-month, 4-month, 12-month and 18-month after transportation from the hatchery. The following conditions are considered a best farming site of nursery culture: swift current, minimum variation of water temperature and salinity, minimum predation and natural disaster such as cyclone.
500 l or 1,000 l polycarbonate/glassfibre tank is commonly used for larval and spat rearing. Ideal water temperature ranges from 26–29°C, salinity 35–36ppt. Seawater must be filtered to at least 1μ and, if available, install an UV-sterilize (in-line type). When the tanks are place directory on the floor, the floor should have a 50–70cm deep groove/gutter for sieving and siphoning. Instead, prepare tank bases with 50–70cm height. Ceiling of the larval rearing room should be painted or covered to protect from falling dusts. All the air tubings must be fed from above the tanks to avoid direct contact to the floor.
Necessary plankton mesh screen sizes and combination of sieves during the spawning and spat production of pearl oyster are summarized as follows. A hard sieve (made of PVC pipe flame) or soft sieve (hand-net type) can be used to select appropriate larval sized.
| Combination | Days | SL/SH | Work |
| 20/53 or 25/53/88 | 0 | 60 | Collecting ova, washing sperm |
| 25/88/105 or 37/53/88 | 1 | 80/65 | 100% WC, TC, Collecting fertilized eggs & D-stage |
| 37/53/125 | 4 | 95/80 | 50% WC, D-stage |
| 53/88/149 | 6 | 105/90 | 100% WC & TC, D-stage selection |
| 88/105/177 | 9 | 120/105 | 50% WC, Selecting D & Umbo |
| 88/105/210 | 11 | 140/125 | 100% WC, TC, Selecting Umbo |
| 88/105/250 | 13 | 160/145 | 50% WC, Selecting Umbo |
| 105/125/500 | 15 | 180/170 | 100% WC, TC, Selecting Umbo |
| 105/125/500 | 17 | 220/210 | 50% WC, Selecting Umbo & Eyed |
| 125/149/177/500 | 19 | 260/250 | 100% WC, TC, Selecting Umbo & Eyed, Spat Collector |
| 125/149/500 | 21 | 300/300 | 100% WC, TC, Collecting Eyed, Spat Collector |
| 177/500 | 28 | 500/400 | 100% WC, TC, Collecting Eyed |
Days=days of work;
D=D-veliger;
Eyed=eyed veliger;
SL/SH=shell length/shell height;
TC=tank change;
Umbo=Umbo veliger;
WC=water exchange.
Collection and selection of larvae should be done with appropriate combination of sieves. The larval tanks should covered with lid to avoid air-born foreign particles and unwanted insect contamination. Rearing water should be filtered to 1μ (if the water is too silty, extra 0.5-0.3μ filter may be required). Each tank will be needed separate filter unit setting to avoid a total accidental loss filter unit failure and contamination. Aeration is to be very gentle during the first few days of rearing and gentle plunging may be needed alt least twice a day; the aeration should increase according to the progress of the rearing. Larval rearing may better to carry out under a dim light condition (indoor) or completely covered with lid (undercover semi-outdoor) to avoid unwanted algae fouling the tank. Tank bottom must be cleaned by siphoning on every 50% water exchange day. Observed larvae under torch for their swimming activity. Tank draining must be done as carefully and quickly as possible without unnecessary shock to the larvae; when taking samples, do not leave larvae in a bucket for long period. It is important to return the larvae in a new tank immediately after collecting the samples. In another word, prepare a new tank before you star draining the tank. Feeding should be done in a manner of scheduled amount and intervals. During the first few days, feeding should be divided into 3–4 separate feedings a day, and into 3-2 separate feedings in the following 2–3 weeks until commencing a drip-feeding method.
| (Day 1) | Draining the incubator and collecting free swimming larvae (D-shaped veliger) with 37μ mesh sieve; taking sample for counting larvae and estimating hatching rate; setup larval tanks; stocking larvae in the rearing tanks (1–2 larvae per ml in each tank); commence feeding larvae according to the feeding schedule*. |
| (Day 3) | 50% rearing water exchange; take larval sample for checking growth. |
| (Day 5) | 100% rearing water exchange; drain the tank completely and collect all the larvae with appropriate combination of mesh screen; take larval sample for counting and growth; return the larvae in new tanks with fresh rearing water; adjust stocking density to around 0.8 larvae/ml. |
| (Day 7) | 50% rearing water exchange; take larval sample for checking growth. |
| (Day 9) | 100% rearing water exchange; drain the tank completely and collect all the larvae with appropriate combination of mesh screen; take larval sample for counting and growth; return the larvae in new tanks with fresh rearing water; adjust stocking density to around 0.8-0.6 larvae/ml. Umbo veliger will be found around this day. |
| (Day 11) | 50% rearing water exchange; take larval sample for checking growth. |
| (Day 13) | 100% rearing water exchange; drain the tank completely and collect all the larvae with appropriate combination of mesh screen; take larval sample for counting and growth; return the larvae in new tanks with fresh rearing water; adjust stocking density to around 0.5-0.4 larvae/ml. |
| (Day 15) | 50% rearing water exchange; take larval sample for checking growth. |
| (Day 17) | 100% rearing water exchange; drain the tank completely and collect all the larvae with appropriate combination of mesh screen; take larval sample for counting and growth; return the larvae in new tanks with fresh rearing water; adjust stocking density to around 0.3-0.2 larvae/ml. Eyed veliger may be seen in the sample. Prepare Spat collectors. |
| (Day 19) | 50% rearing water exchange; take larval sample and check growth. If eyed floggers consist of around 80%, drain the tank, collect and count the larvae for settlement program, setup new tanks with spat collectors; adjust stocking density to 0.2-0.1 larvae/ml. |
| (Day 21) | 100% water exchange; drain the tank and collect larvae for settlement program; setup new tanks with spat collectors; take larval sample for counting and measurements. Settlement may occur around this day. Take larval sample for measurements swimming stage. Commence flow-through; check carefully in the sieves for larvae from the flow-through system and return the collected larvae in the tank. Increase flow rate gradually to 200% per day on day 25. |
| (Day 28–31) | Tank change; drain the tank, collect all the swimming stage, transfer the collectors in a new settlement tank. Majority of the larvae completes settlement and they are now young oysters (spat). Those settled on the tank surface should be carefully collected with a soft brush during tank draining, then they are resettled onto the spat collectors in the settlement tanks. Commence drip-feeding method; increase flow rate to 300% on day 31. |
| (Day 35) | Decrease stocking density of the spat to around 30,000–50,0000 spat per 1,000 1 tank. Increase flow rate to 400% on day 35. |
| (Day 40–42) | Take spat collector samples for estimating settled number of spat on the collectors. Transfer the spat collectors for ocean nursery culture at farm(s). |
* Feeding Schedule for the larval and spat rearing for P. margaritifera and P.penguin.
| Water Change Rate % | Days of Run | Feeding Total | Algal Species (cells/larva/day) | ||
|---|---|---|---|---|---|
| (Sieving Mesh Screen Size) | (Estimated SL) | cells/larva/day) | C.mulleri | P.lutheri | T.suesica |
| 100 (S1; 20/50) | 0 (60) | 0 | 0 | 0 | 0 |
| 100 (TC; 37/50/100) | 1 (85) | 500 | 200 | 300 | 0 |
| 0 | 2 (85–90) | 1,000 | 400 | 600 | 0 |
| 50 (37/50/100) | 3 (85–95) | 1,500 | 600 | 900 | 0 |
| 0 | 4 (85–100) | 2,000 | 800 | 1,200 | 0 |
| 100 (TC; 50/100/200) | 5 (85–105) | 3,000 | 1,200 | 1,800 | 0 |
| 0 | 6 (85–110) | 4,000 | 1,600 | 2,400 | 0 |
| 50 (50/100/200) | 7 (85–120) | 5,000 | 2,000 | 3,000 | 0 |
| 0 | 8 (85–130) | 6,000 | 2,500 | 3,500 | 0 |
| 100 (TC; 50/100/200) | 9 (100–140) | 7,000 | 3,000 | 4,000 | 0 |
| 0 | 10 (110–150) | 8,000 | 3,500 | 4,500 | 0 |
| 50 (50/100/200) | 11 (120–165) | 9,000 | 4,000 | 5,000 | 0 |
| 0 | 12 (130–180) | 1,000 | 4,500 | 5,500 | 0 |
| 100 (TC; 50/100/200) | 13 (130–200) | 12,000 | 5,000 | 6,000 | 0 |
| 0 | 14 (150–220) | 14,000 | 6,000 | 6,500 | 0 |
| 50 (50/100/500) | 15 (150–240) | 16,000 | 6,500 | 7,000 | 0 |
| 0 | 16(150–260) | 18,000 | 7,000 | 8,000 | 0 |
| 100 (TC; 100/160/500) | 17(160–280) | 20,000 | 8,000 | 9,000 | 0 |
| 0 | 18(160–300) | 24,000 | 9,000 | 10,000 | 0 |
| 50(100/160/500; collector) | 19(180–320) | 28,000 | 11,000 | 11,000 | 0 |
| 0 | 20(180–350) | 32,000 | 13,000 | 12,000 | 0 |
| 100(TC;100/200/500; collector) | 21(180–380) | 36,000 | 15,000 | 14,000 | 0 |
| 100% Flothru (100/200/500) | (22(200–420) | 40,000 | 17,000 | 16,000 | 0 |
| " | 23(200–460) | 45,000 | 19,000 | 18,000 | 0 |
| " | 24220-500) | 50,000 | 22,000 | 20,000 | 0 |
| 20% Flothru (100/500) | 25(220–550) | 55,000 | 25,000 | 22,000 | 0 |
| " | 26(240–600) | 60,000 | 28,000 | 24,000 | 0 |
| " | 27(240–700) | 60,000 | 28,000 | 24,000 | 0 |
| " | 28(260–800) | 70,000 | 32,000 | 28,000 | 0 |
| " | 29(280–900) | 70,000 | 32,000 | 30,000 | 0 |
| " | 30(280–1000) | 70,000 | 32,000 | 30,000 | 0 |
| 300% Flothru (TC; 200/500) | 31(300–1100) | 80,000 | 36,000 | 33,000 | 0 |
| " | 32(340–1200) | 80,000 | 36,000 | 33,000 | 0 |
| " | 33(360–1300) | 80,000 | 36,000 | 33,000 | 0 |
| " | 34(400–1500) | 90,000 | 40,000 | 36,000 | 0 |
| " | 35(450–1600) | 90,000 | 40,000 | 36000 | 0 |
| " | 36(500–1800) | 90,000 | 40000 | 36,000 | 1,556 |
| " | 37(550-2mm) | 100,000 | 45,000 | 40,000 | 1,667 |
| 400% Flothru | 38(600-2.2mm) | 100,000 | 45,000 | 40,000 | 1,667 |
| " | 39(700-2.5mm) | 110,000 | 50,000 | 40,000 | 2,222 |
| Harvest;400% Flothru (TC;500) | 40(800-2.8mm) | 120,000 | 50,000 | 45,000 | 2,778 |
| " | 41(1mm–3.2mm) | 120,000 | 50,000 | 45,000 | 2,778 |
| " | 42(1.2mm–3.6mm) | 140,000 | 50,000 | 50,000 | 4,444 |
When larvae become about 240μ in shell length, they develop eye (black) spot (one on each valve) and bear foot, of which they can crawl. This is a good indication for settlement, being approximately 3–4 days from settlement. When the proportion of the eyed veliger stage increased to 70–80%, spat collectors are to be installed in the settlement tank. The settlement normally complete over the next 1 week. It should be noted that when they settle (=metamorphose from veliger) to plantigrade or crawling spat, they stop feeding because of formation of gills. Once they form gills, filtration rate jump up and the feeding rate should be increased accordingly.
Types of spat collector materials are: Christmas tree (mussel culture rope), black plastic sheet (60×40cm), 60–80%-shade cloth (or 60×40cm sheet), 2mm black plastic mesh, (60×40cm sheet), bunch of fluffy rope fibre, venetian blind shape PVC pipe half-cut. Spat can also be settled on the tank surface, and later brushed off from the surface and collected for resettlement on to the spat collectors. 50 sheet type collectors (60cm × 40cm) can be set in one 500 l tank. Ideal number of spat on each collector may be around 200–400 (both sides), based on the healthy growth and convenience of sorting of spat/juveniles during ocean nursery culture. When the spat reach 2–5mm in shell length, they are transferred from the settlement tank to the ocean nursery.
(Pearl Farming)
Federman, P. (1990). Biotechnology: a new dawn for pearl farming. Modern Jeweler. September, 1990. 7pp.
George, C.D. (1978). The Pearl. A report to the government of Papua New Guinea, The Food and Agriculture.
Organisation of the United Nations and the Asian Development Bank. Samarai, Milne Bay Province, Papua New Guinea. i–vi, 169 pp.
Taburiaux, J. (1989). Pearls, their origin, treatment and identification. Chilton Book Co., Radnor, PA. 247pp.
(Pinctada margaritifera).
Ito, M. (1996a) Hatchery efforts in Tarawa. Pearl World, Dec. 1995/Jan.1996, Vol.3, No.5: 3–5.
Ito, M. (1996b) Hatchery spat production of Pinctada margaritifera in Tarawa, the Republic of Kiribati. SPC Pearl Oyster Information Bulletin, No.9, September 1996: 8–11.
Ito, M., J.R.Whitford, B.Tioti and T.Tabee (1995) Artificial propagation of pearl oysters: Present status and future development in Oceania. Aquaculture Workshop on Present and Future of Aquaculture Research and Development in the Pacific Island Countries, Technical Paper S7-1, 13pp. Kingdom of Tonga.
(Pinctada maxima)
Ito, M. 1992. Result of the seed production of the silver-lipped pearl oyster, Pinctada maxima, at the Albany Island Hatchery in 1991: Final report. Unpublished data. Overseas Pearl Oyster Aquaculture Research Division, Nisshin Trading Co. Ltd., Kobe, Japan.
Ito, M. 1998a. Commercial spat production of Pinctada maxima at Roko Island Hatchery, NE of Australia, with in vitro fertilisation technique. Pearl Oyster Information Bulletin, No.11, 1998. South Pacific Commission, Noumea, New Caledonia.
Ito, M. 1998b. Breakthrough in hatchery spat production of the silverlip pearl oyster. Feb/Mar. 1998. Australasia Aquaculture, Hobart, Australia.
Rose, R.A. (1990) A manual for the artificial propagation of the silverlip or goldlip pearl oyster, Pinctada maxima.
(Jameson) from Western Australia. Fish. Dept., Western Australian Marine Research Laboratories, WA Australia, 41 pp.
Tanaka,Y. and M.Kumeta (1981) Successful artificial breeding of the silver-lip pearl oyster, Pinctada maxima (Jameson). Bull. Natl. Res. Inst. Aquacult. (Japan).,2: 21–28. (in Japanese with English abstract)
Wada, S. (1932) On the artificial fertilization and development of silverlip pearl oyster Pinctada maxima (JAMESON). Kagaku Nanyo, Vol.4 (No.3), p.202 – 208, Figs. 1–18.
(Pinctada spp.)
Hayashi, M. and K. Seko (1986) Practical technique for artificial propagation of Japanese pearl oyster (Pinctada fucata). Bulletin of the Fisheries Research Institute of Mie. No.1. Sept. 1986. p.39–68. (in Japanese with English abstract)
(Pteria penguin)
Borrero, F.J. (1994). Potentials of pearl oyster culture on the Colombian Caribbean -Preliminary results. Technical Forum Abstracts, Pearls'94, International Pearl Conference and Exposition, Hawaii, U.S.A. p.61.
Farell, S., D. McLaurin and E. Arizmendi (1994). Perspectives and opportunities of pearl oyster culture development on the coast of Sonoma, Gulf of California, Mexico. Technical Forum Abstracts, Pearls'94, International Pearl Conference and Exposition, Hawaii, U.S.A. p.57–58.
Kozuka, M., I.Shinmura, M.Toyoda and A. Yamaguchi (1960). Mabe Pteria penguin (Röding) zoshoku ni kansuru kisoteki kenkyu [IV]. Yosei no shiiku to chigai no seicho (Studies on the propagation of Mabe Pteria penguin (Röding) [IV] Larval rearing and growth of spat.) (in Japanese). Investigation Report of the Oshima Branch, Fisheries Experimental Station, Kagoshima Prefecture, Japan : 1–13.
Kozuka, M., A. Yamaguchi, O.Deshimaru and M.,Toyoda (1961). Mabe Pteria penguin (Röding) zoshoku ni kansuru kisoteki kenkyu [V]. Yosei no shiiku to chigai no seicho (Studies on the propagation of Mabe Pteria penguin (Röding) [IV] Larval rearing and growth of spat.) (in Japanese). Investigational Report of the Oshima Branch, Fisheries Experimental Station, Kagoshima Prefecture, Japan :1–12.
Matsui, Y. and M. Yamaguchi (1958). On the history of pearl culture in Pteria penguin (Röding) and some discussion on percentage of death after the collecting in Pteria penguin. Bull.Nippon Inst.Sci.Res.Pearls (3), 1959.
Millous, O. (1977). Rapport de stage a la Ryukyu Pearl Co. Ltd. Iriomote et de la viste a prefecture d'Okinawa, Japon. Rapp.CNEXO/COP/AQ Tahichi :77–185.
Monteforte, M. (1994). Perspectives for the installation of a pearl culture enterprise in Bahia DeLa Paz, South Baja California, Mexico. Technical Forum Abstracts, Pearls'94, International Pearl Conference and Exposition, Hawaii, U.S.A. p.49–50.
Monteforte, M. and C. Aldana (1994). Spat collection, growth and survival of pearl oyster Pteria sterna under extensive culture conditions in Bahia De La Paz, South Baja California, Mexico. Technical Forum Abstracts, Pearls'94, International Pearl Conference and Exposition, Hawaii, U.S.A. p.59–60.
Monteforte, M. and P. Saucedo-Lastra (1994). Breeding cycle of pearl oysters Pinctda mazatlanica and Pteria sterna in Bahia De La Paz, South Baja California, Mexico. Technical Forum Abstracts, Pearls'94, International Pearl Conference and Exposition, Hawaii, U.S.A. p.31–32.
Monteforte, M., P. Saucedo, H. Bervera, V. Perez and H. Wright (1994). Repopulating of natural beds of pearl oysters Pinctda mazatlanica and Pteria sterna in Bahia De La Paz, South Baja California, Mexico. Technical Forum Abstracts, Pearls'94, International Pearl Conference and Exposition, Hawaii, U.S.A. p.15–17.
Monteforte, M., H. Bervera, S. Morales, V. Perez, P. Saucedo and H. Wright (1994). Results on the production of pearls in Pinctada mazatlanica and Pteria sterna from Bahia De La Paz, South Baja California, Mexico. Technical Forum Abstracts, Pearls'94, International Pearl Conference and Exposition, Hawaii, U.S.A. p.55–56.
Oshima, Y. (1969). Mabe. In: Handbook of Aquaculture, Y.Oshima ed., p.423–426. Suisansha, Tokyo, Japan.
Phillipson, P.W. (1989). The marketing and processing of pearl shells in south Korea, Taiwan and Japan. In: The marketing of marine products from the South Pacific. P.Phillipson ed., p.224–238. Institute of Pacific Studies, USP, Suva, Fiji.
Shinmura, I. and M.Toyoda (1956). Mabe Pteria penguin (Röding) zoshoku ni kansuru kisoteki kenkyu [I]. Jinko jusei to hassei ni tsuite. (Studies on the propagation of Mabe Pteria penguin (Röding) [I] Artificial fertilization and development.) (in Japanese). Investigational Report of the Fisheries Experimental Station, Kagoshima Prefecture, Japan :32–48.
Shinmura, I. and M.Toyoda (1957). Mabe Pteria penguin (Röding) zoshoku ni kansuru kisoteki kenkyu [II]. Suisonai jinko shiiku ni tsuite (Studies on the propagation of Mabe Pteria penguin (Röding) [II] Artificial breeding in the tanks.) (in Japanese). Investigational Report of the Fisheries Experimental Station, Kagoshima Prefecture, Japan :259–270.
Shinmura, I., M. Toyoda and M. Kozuka (1959). Mabe Pteria penguin (Rding) zoshoku ni kansuru kisoteki kenkyu [III]. Yosei no shiiku to koki hassei (Studies on the propagation of Mabe Pteria penguin (Röding) [III] Larval rearing and development.) (in Japanese). Investigational Report of the Oshima Branch, Fisheries Experimental Station, Kagoshima Prefecture, Japan :1–13.
Shirai, S. (1994). Pearls and pearl oysters of the world. Marine Press Color Guide 6. Marine Olanning, Ishigaki, Okinawa, Japan. pp.108.
Tanaka, H. (1990a). Winged pearl shell newly found in Tonga. Pearl Oyster Information Bulletin (1), p.10.
Tanaka, H. (1990b). Winged pearl shell newly found in Tonga. Pearl Oyster Information Bulletin (2), p.15.
Uwate, K.R., Kunatuba, P., Raobati, B. and Tenakanai, C. (1984). A review of aquaculture activities in the Pacific Islands region. Pacific Islands Development Programme, East-West Center, Honolulu, 538 pp.
Ward, T. (1993). The pearl industry in Queensland and Torres Strait. Consultant's Report to the Queensland Department of Primary Industries, Brisbane, Queensland. pp. 77.
Yamaguchi, A. and H. Shiihara (1961). Mabe Pteria penguin (Röding) zoshoku ni kansuru kisoteki kenkyu [VI]. Chigai no shiiku to koki hassei (Studies on the propagation of Mabe Pteria penguin (Röding) [VI]. Growth of spat.) (in Japanese). Bulletin of the Fisheries Experimental Station, Kagoshima Prefecture, Japan : 426–432.
(Micro-algae Culture)
Brown, M.R., S.W. Jeffrey and C.D. Garland 1989. Nutritional aspects of microalgae used in mariculture; a literature review. CSIRO Marine Laboratories Report No. 205, 44 pp.
Guillard, R.R.L. and J.H.Ryther 1962. Studies of marine planktonic diatoms .I. Cyclotella nana Hustedt, and Detonula confervacea (Cleve) Gran. Can. Jour. Microbiol., Vol. 8: 229–239.
Ito, M. (1995) A manual of micro-algae culture for hatchery training of the black-lipped pearl oyster, Pinctada margaritifera (Linnaeus), in tropical atoll conditions. Dept. Zool., James Cook University of North Queensland, Australia. 18 pp.
Ito, M. 1992. Result of the seed production of the silver-lipped pearl oyster, Pinctada maxima, at the Albany Island Hatchery in 1991: Final report. Unpublished data. Overseas Pearl Oyster Aquaculture Research Division, Nisshin Trading Co. Ltd., Kobe, Japan.
Jeffrey, S.W. and C.D. Garland. 1987. Mass culture of microalgae essential for mariculture hatcheries. Australian
Fisheries, No. 164, pp.5.
Jeffrey, S.W. and C.D.Garland. 1989. Micro-algae for mariculture Newsletter. No. 6, FIRTA Grant 86/81. pp.7.
Jeffrey, S.W. and C.D. Garland. 1990. Micro-algae for mariculture Newsletter. No.7, FIRTA Grant 90/63. Pp.8.
The consultant was engaged with the following Terms of Reference for GCP/RAS/116/JPN on the pearl oyster hatchery development project at the Ministry of Fisheries, Nuku'alofa, the Kingdom of Tonga, between 5th April and 18th May in 1999:
To set up a pearl oyster seed production system with necessary equipment available at the existing aquaculture facility;
To set up a micro-algae culture system required for pearl oyster seed production;
To provide staff of the Fisheries Department and other participants with training of micro-algae culture;
To advise on collection and selection of spawners of Pinctada margaritifera and Pteria penguin and their transportation method;
To demonstrate spawning induction and early stage of larval rearing with instruction of feeding schedule, and to advise on management of larval rearing and spat collection method;
To prepare a manual of pearl oyster hatchery production;
To produce an overall report to cover the above subjects.
| 5 Apr. (Mon) | Dept. TSV at 11:00 (AN133), Arr. NADI at 0:25 via SYD (FJ912) |
| Overnight stay in Nadi. | |
| 6 Apr. (Tue) | Meeting CTA, collecting micro-algae master stock culture and chemicals. |
| Dept. NADI at 16:50 (FJ211), Arr. TONGA at 19:10 | |
| Meeting Mr. Fa'anunu (Chief, Aquaculture Div.) and Mr. Kikutani (JICA Project) | |
| 7 Apr. (Wed) | Meeting Fisheries Staff, inspecting hatchery facility at Ministry of Fisheries. |
| Listing up additional equipment and materials for micro-algae culture. | |
| Commenced micro-algae culture room set-up. Culture equipment cleaning and preparation. | |
| Nutrient media preparation including autoclaving culture media for stock culture. | |
| 8 Apr. (Thu) | Culture media preparation continued. |
| Commenced laminar flow chamber (clean bench) making. | |
| Demonstrated preparation of equipment and nutrient media, and aseptic technique for inoculation of stock culture. | |
| 9 Apri. (Fri) | Commenced culture preparation room and spawning room set up |
| Commenced micro-algae stock culture training, including identifying, counting and estimating density of micro-algae using haemocytometer; chemical and culture media preparation; and equipment preparation and set-up. | |
| 10 Apr. (Sat) | Equipment making continued. |
| 11 Apr. (Sun) | Equipment making continued. |
| 12 Apr. (Mon) | Micro-algae intermediate (high density) culture preparation commenced; including nutrient media preparation and autoclaving equipment. Equipment making for spawning and larval rearing commenced. |
| Mr. Yamamoto (Tahiti Pearl) visited Fisheries, negotiated for supplying blacklip pearl oyster spawners. | |
| 13 Apr.(Tue) | Demonstrated micro-algae intermediate (high density) culture technique. Equipment making continued. |
| 14 Apr.(Wed) | Micro-algae culture room set up completed. Micro-algae intermediate culture training commenced, including aseptic inoculation of stock and intermediate culture, and culture media preparation. Equipment making continued. |
| Meeting with Secretary (Akau'ola), Deputy Secretary (Mr. M. Akau'ola), Mr. Kikutani (JICA Project) and Fisheries Officer (Mr. Fale). | |
| 15 Apr. (Thu) | Micro-algae culture training continued. Equipment making continued. |
| 16 Apr. (Fri) | Micro-algae culture training continued. Equipment making continued. |
| 17 Apr. (Sat) | Micro-algae culture training continued. Equipment making continued. |
| 18 Apr. (Sun) | Micro-algae culture training continued. Equipment making continued. |
| 19 Apri. (Mon) | Demonstrated micro-algae sampling, counting and computing culture density. |
| Equipment and culture media preparation for microalgae mass culture commenced. | |
| 20 Apr.(Tue) | Demonstrated micro-algae mass culture technique. Equipment preparation for transportation of brood stock. |
| Preparation for spawner transportation from Vava'u and Tahiti Pearl (Nuku'alofa). | |
| 21 Apr. (Wed) | Micro-algae mass culture training commenced. Demonstrated micro-algae subculture techniques. Equipment and system preparation for broodstock maintenance. |
| Meeting with Mr. Yamamoto (Tahiti Pearl) for collecting & transportation of blacklip pearl oysters. | |
| 22 Apr. (Thu) | Dept. Nuku'alofa at 08:00am., arr. Vava'u at 10:00am. Meeting Officer-incharge, JOCV of Vava'u Fisheires. Inspecting spawners of blacklip and giant black-winged (Mabe) pearl oysters, including sexing and examining gonad conditions. Selected 30 Mabe (15 males and females each). Preparation of transportation. |
| 23 Apr. (Fri) | Demonstrated transportation techniques of spawners |
| Transportation of spawners from Vava'u to Nuku'alofa. | |
| Dept. Vava'u at 08:35am, arr. Nuku'alofa at 10:30am, arr. | |
| Commenced conditioning of spawners at 11:30am. | |
| Demonstrated shell cleaning for spawning purpose, sexing and gonad examination. | |
| Demonstrated micro-algae culture for Vava'u and Ha'api Fisheries Officers. | |
| 24 Apr. (Sat) | Transportation of spawners of blacklip pearl oyster from Tahiti Pearl (Nuku'alofa). |
| Dept. Fisheries at 10:00am, arr. Tahiti Pearl at 11:00am, selecting spawners on-site, arr. Fisheries at 01:00pm, commenced conditioning of spawners. | |
| Demonstrated sexing and gonad examination for the participants of training. | |
| 25 Apr. (Sun) | Seawater supply system setup continued for spawning room. |
| 26 Apr. (Mon) | System set-up for spawning and larval rearing continued. Air supply system setup completed. |
| Demonstrated micro-algae subculture techniques for mass culture. Equipment preparation for spawning induction. | |
| Demonstrated standard spawning induction techniques | |
| 27 Apr. (Tue) | Demonstrated artificial maturation and fertilization method. Conducted spawning induction training for the participants. Equipment preparation for incubation, hatching and larval rearing. |
| 28 Apr. (Wed) | Demonstrated artificial maturation and in vitro fertilization of Mabe. |
| In vitro fertilisation technique and larval rearing system set-up training commenced. | |
| Demonstrated sampling and counting eggs, and estimating fertilisation and hatching rates. | |
| 29 Apr. (Thu) | Demonstrated feeding technique, sampling and counting larvae. |
| Demonstrated spat culture techniques, sampling and estimating growth and survivorship of spat. | |
| Training of larval rearing of Mabe commenced. In vitro fertilization trial continued. | |
| 30 Apr.(Fri) | Demonstrated larval rearing system management, including sieving, water exchange, equipment cleaning, feeding adjustment, sampling larvae and estimating growth and survivorship. |
| 1 May (Sat) | Larval rearing (Mabe) and micro-algae culture training continued. |
| 2 May (Mon) | |
| | | In vitro fertilization trial continued. |
| 6 May (Tue) | |
| 7 May (Fri) | Obtained Ammonia solution and conducted artificial maturation of ova and sperm activation of Mabe. Demonstrated fertilization technique. |
| 8 May (Sat) | Commenced larval rearing training of Mabe. |
| 10 May (Mon) | Demonstrating spat tank setup and commenced spat collector making. Demonstration and training of in vitro fertilization of blacklip pearl oyster. |
| 11 May (Tue) | Commenced larval rearing training of blacklip pearl oyster. |
| | | Continued larval rearing and micro-algae culture training. |
| 18 May (Tue) | Handed hatchery manual and recommendation report to the Fisheries. |
| Debriefing at Fisheries. | |
| Dept. Nuku'alofa at 20:10pm (FJ210). | |
| Arr. Nadi at 20:40pm. Overnight stay in Nadi. | |
| 19 May (Wed) | Dept. Nadi at 13:00pm (FJ921). |
| Arr. BNE at 15:15pm. | |
| Dept. BNE at 18:55pm (QF540). | |
| Arr. TSV at 20:55pm. |
List of Project Field Documents
| No. 1 | - | Survey of commercial seaweed available in South-East Viti Levu (Fiji Islands): A preliminary study of farming potential of seaweed species present in Fiji by T.Pickering and S.Mario |
| No. 2 | - | Commercial sponge survey in Kiribati and sponge farming development in the South Pacific by R.Croft |
| No. 3 | - | Comparative taste test on Nile tilapia and marine fish in Samoa and Nauru by L. Bell, et al |
| No. 4 | - | Survey of seaweed “Limu Tanga'u” (Cladosiphon sp) in Tongatapu, Ha'apai and Vava'u Islands in Tonga: Observation on growth in December 1996 by E.Lovell |
| No. 5 | - | Potential of commercial development of Mabe pearl farming in Vava'u Islands, Kingdom of Tonga by T.Yamamoto and H.Tanaka |
| No. 6 | - | Potential of milkfish farming development in Fiji. by T.Yanagisawa by E.Dela Cruz |
| No. 7* | - | Sea cucumber ranching in Japan and applications for the South Pacific by T.Yanagisawa |
| No. 8 | - | Market Survey of Aquarium Giant Clams in Japan by H.Okada |
| No. 9 | - | Feasibility Study on the relocation of Naduruloulou Aquaculture Research Station, Fiji by E.Woynarovich |
| No. 10 | - | Technical guidance on pearl oyster hatchery development in the Kingdom of Tonga by M.Ito |
| No. 11* | - | Construction of tilapia demonstration pond and technical guidance on its farming in Samoa by S.Nandlal |
| No. 12* | - | Feasibility study of green snail (Turbo marmoratus) and trochus (Trochus niloticus) transplantations to Samoa by M.Amos |
| No. 13* | - | Pearl marketing trends with emphasis on Black Pearl Markets by Y. Hisada |
| No. 14* | - | Manual of marine snail seed production and stock enhancement by K. Kikutani, H. Yamakawa, et al. |
| No. 15* | - | Technical guidance on Java carp and common carp seed production at the Highlands Aquaculture Development Centre, Papua New Guinea by Z. Jangkaru |
| No. 16* | - | Recommendation towards shrimp farming industry development in Solomon Islands by H. Kongkeo |
| No. 17** | - | Potential of Eucheuma seaweed farming development in Tonga and Samoa by D.Luxton |
* In printing
** Under preparation
