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T U R T L E F A R M I N G F O RT H E S O U T H P A C IF IC

BY DR. U. RAJ, University of the South Pacific, Suva, Fij iThe concept of turtle farming has been interpreted in several ways. A true turtle farm must include a breeding stock of turtles; that is, it must

not rely on wild populations for eggs or younghatchlings for rearing in captivity. Until now, turtle rearing activities in the South Pacific andthroughout the world (except on Grand Cayman)have been dependent on a supply of eggs and hatchlings from the nesting beaches of the wild. Inthis regard the practice has been on e of turtleranching rather than turtle farming. Also, whenturtle farming is being considered, it must beclearly defined either as a venture on a commercial scale or as a village-level subsistence activity.Reviewing the turtle farming -turtle ranching activities of various organisations and isolatedpopulations of oceanic peoples around the world,one is led to conclude that nearly all efforts havebeen directed towards ranching turtles in small.non-commercial ventures. However, attempts arenow being made to systematize use of the turtleresource in various places. For example, inAustralia, a Government organisation. EcologyProperty Limited, is now involved in research andsupport for the utilisation of marine turtles by theabor ig inal population of the Torres Strai ts .Similarly, Government agencies in the MiddleEast, Papua New Guinea and the Caribbean are

in the process of formulating policies, throughres ear ch, desig ned to realise the full potential othe mar ine turtle. The only turtle farm nooperating on a commercial scale exists on GranCayman Island in the West Indies.In the South Pacific it is clearly evident thascientific information on the turtle resource imeagre in spite of the traditional place of thianimal in Oceanic societies. Two general reviewon South Pacific Islands marine turtle resourcehave been published by Hirth and HendricksonSubsequent to these reports, no other reviewhave appeared . At SPC's Seventh TechnicaMee ting on Fisheries, held in Ton ga in 1974, iwas agreed that information on marine turtleshould be forwarded by the fisheries agencies oeach country to SPC and the University of thSouth Pacific in order to centralise data anenable periodic reviews of this resource to be undertaken. It was also recommended that SPCfacilitate visits to interested territories by stafengaged in the SPC project for consultation. Onlyone country forwarded information on turtles andexcept for a visit by the author to the CookIslands where the SPC turtle project is basedwider consultation on marine turtle resource othe Sou th Pacific h as not been achieved. In order to provide a worthwhile review of thireso urce it is absolutely essential that up-to-dat

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information be gathered and processed centrallyfor distribution.The SPC turtle project is divided into two sub-projects. One is based at the University of theSouth Pacific in Suva, the other at Rarotonga inthe Cook Islands. The objectives of the Fiji partof the project are mainly scientific; they includestudy of the hatching rate under laboratory condit ions ( temperature, duration of incubation) ,

study of the rate of survival and of its independence upon water quality, density in the tanks,food quality, conversion rate, bacterial diseases.fungal infections and the osmotic regulation. Theobjectives of the studies in Rarotonga are directedrather towards the economic feasibility of turtlefarming in relation to the local food supplies andlogistical problems. Both project managers areworking close together in co-operation with thelocal Fisheries Departments.From the little data available, it appears thatthe South Pacific Islands do not have enormousbreeding colonies of turtles. Five species ofmarine turtles have been recorded from the SouthPacific. These are Chelonia mydas (green turtle),Eretmochelys imbricata (hawksbill turtle), Carettacaretta (loggerhead turtle), Lepiclochelys olivacea(Pac i f ic r id ley ) an d Dermocheivs coriacea(leatherback turtle). Among these, the green turtleand the hawksbill turtle are the commonest; theother species are rarely encountered. Althoughthese two species nest widely in the South Pacific.the numbers of individuals visiting the nestingsites are not very large compared with those inNorthern and North-East Australian islands or inthe Caribbean. For this reason alone, use of wildeggs and hatchlings must be viewed with care.The most logical approach appears to be theestablishment of a breeding colony of turtles. Ex

perience shows that the green turtle is the mostprofitable choice. It grows faster and its flesh ispreferable to the hawksbill. Also, it is a herbivorous species, whereas the hawksbill clearlyprefers animal flesh for food.A technique of breeding the green turtle in captivity has been evolved in Grand Cayman Island.It seems worthwhile to learn this technique andapply it in our own situation in the South Pacific.

The main effort on the part of the University ofthe South Pacific will be to set up a breeding pooland to stock it with adult turtles. The breedingpool on the mariculture farm in Grand CaymanIsland is 200ft (60.5m) by 86ft (26.5 m) with anarea of about 0.4 acres ( 0.2 ha). It is about 10 ft(3.1 m) deep at one end and shelves up to an artificial beach about 35 ft (10 m) high on the otherside. The capacity of this pool is quoted as 0.75million gallons of seawater and the rate of waterchang e is given as 18 changes per day. The costof construction and proper maintenance of such apool located on a South Pacific Island would appear. at first sight, to be expensive, but by usingsome natural beaches and shores to enablenatural flushing at each tide, the task could be accomplished with ease and relatively cheaply.

The capture of breeding females can be carriedout during a nesting season but the capture ofmature males, which normally do not come up onthe beaches, may prove difficult, although not impossible. Indeed, experience in Cayman Islandshows that it is almost necessary to introduce wildmales in the breeding pool to induce courtshipand mating, otherwise males and females cohabiting the pool become too familiar with eachother to mate. It is possible that in the nearfuture frozen sperm may be obtainable from theCayman farm for artificial insemination.

Thus, by actually producing farmed eggs andhatchlings we can ensure that the wild populationis not in any danger of depletion, should turtlefarming become a reality. Indeed, by releasing apercentage of farm-produced hatchlings we canhelp conserve and increase the wild population. Itis therefo re recomm ended that research effort bedirected to actually breeding turtles in captivity.not only from the egg stage but also by inducingmating and egg-laying in artificial situations.The South Pacific Commission's own research

programme on turtles has contributed to a greatersuccess rate in incubation and hatching in artificial situations. According to our studies, hatching and eme rgency rates of about 100 per centare possible compared to about 50 per centrespectively, in nature. From these figures it is apparent that by doubling the hatching success ofwild eggs one can remove 50 per cent of the hatchlings for artificial rearing and allow the samenumber of young to enter the wild population.Rearing the hatchlings in artificial ponds andfenced areas of sea has been widely practised inthe south Pacific. Nevertheless, the stocking andfeeding rates have been very variable. Our

research indicates that there is an optimumstocking rate which depends on the quality ofpond water, size of hatchlings and availability offood. Increase in density of individuals leads toconstant biting, not unlike pecking in chickens.Also, constant renewal of pond water or treatment of standing water is essential to avoid fungalinfection, particularly in hatchlings up to a year inage. The fungal infection, responds to treatmentby 1 per cent of pottasium perm angan ate. Theother co mm on problem encou ntered in therearing of hatch lings is Pseudomonas infection.particularly in ponds with depressed salimites.The m ost effective cure is Chloro myc etin givenorally, in solution. However, unless the pond isflushed and cleared of Pseudomonas, this infection is persi sten t and usually fatal. The refor e.research on the disease problems and search foreffective cures must continue. It is pertinent tonote h ere that the Cayman farm is also experiencing widespread fungal and bacterial infectionsa m o n g s t t h e h a t c h l i n g s ( p e r s o n a l c o m mu n ica t io n ) .Research on diet of green turtles has been ex

tensive. The composit ion of an ar t if icial lyS O U T H P A C I F I C B U L L E T I N , T H I R D Q U A R T E R , 1 9 77

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Turtle hatchlings: Hatching of turtles in captivity may contribute to conservation of the species.prepare d and a good balanced diet has beenpublished by Simon, Ulrich and Parkes. Manufacture of such a feed on a small scale appears expensive and inappropriate. We must continue toevolve a diet similar to this but drawn from inexpensive regional food sources. In this regard,research must be encouraged on further analysisof the natural foods of green turtles in the SouthPac i f ic ( ex amp le , Syringodium isoetifolium,Halodule uninervis, Halophila ovalis, Deplantherawrighti, Thallasia testidunum, Chaulerpa spp.).Also, a blend of other possible sources of food,for example coconuts, mangrove leaves, tropicalfruits and succulent plants must be investigated asan alternate diet. Given the increasing demandfor fish for human consumption and the risingc o s t s o f f i s h c a p t u r e , i t w o u l d a p p e a runeconomical to feed turtles largely on fish,although some form of animal protein, such asfish meal, might well be used as supplementarydiet.

If a true turtle farm is established in the SouthPacific rt is most likely that the first individuals

will take at least two to three years to breed. It well-known that mature females breed only eversecond or third year. Therefore, husbandry oadults and sub-adults must be understood. In thregard, stocking rate and hygiene will form thmain areas of study. A substantial part of this information may be obtained from the mariculturfarm.In conclusion, it would seem most appropriatto concentrate research efforts on establishing breeding colony of green turtles for the SoutPacific. It is quite possible that this could becoma central agency in supplying farm eggs and hach l in g s to a l l in te r es te d I s lan d te r r i to r ieResearch must continue on the diet and diseasproblems of rearing hatchlings and sub-adults. Athe same time an up-to-date review of the turtlresource of the South Pacific is required, while study of the supply and demand of turtle and tutle produce, locally and overseas, will provvaluable. Island governments of the region muformulate a joint and effective policy, possibthrough similar legislations, to govern the turtreso urce of the South Pacific.

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