3.1 As a result of the survey conditions are believed favourable for large scale oyster culture in several areas in Mahé and, it is thought that by applying the latest techniques and methods, oysters can be produced in sufficient numbers for the anticipated increase in tourist trade as well as for an expanded local market. Oysters were found growing naturally in a number of localities in Mahé and Prasline as well as on some of the other outlying islands of the Seychelles group, but at present they do not occur in sufficient numbers to supply more than a very small local demand. No serious efforts are being made now to culture them although in the past there have been attempts on Prasline.
3.2 To raise oysters on a large scale commercial basis the following basic conditions are necessary:
Adult oysters which produce the young oysters or spawn must be present in nearby waters and in sufficient numbers to ensure adequate rates of reproduction or other sources of supply of seed oysters must be available at a reasonable cost.
The oceanographic conditions of the area must be suitable for oyster growth especially the salinity and water temperatures.
The water must contain adequate phytoplankton suitable for food for oysters and their larvae.
The farming area must be protected by nature or by construction against violent wind and wave action.
The water must be sanitarily clean as well as protected from industrial wastes and chemicals.
3.3 As these conditions can be met in and around Mahé, it is recommended that an oyster culture pilot project be established at Anse à la Mouche to determine the best and most efficient methods for producing oysters in amounts sufficient to meet future anticipated market demands.
3.4 It is also recommended that a qualified shellfish expert be engaged to direct and actively supervise the project, preferably someone who has had considerable knowledge and/or experience with the culture of oysters on a large-scale commercial basis, and, who is familiar with the latest developments in oyster culture.
3.5 It is not necessary for a detailed research programme of the biology-life history type on the native oyster to be complete before engaging in the pilot scheme. The expert will have sufficient basic information and knowledge to proceed with the preliminary project following the suggested plan of operations included in this report; and as an experienced shellfish expert he will soon acquire the additional specific biological information necessary for the pilot-scheme in the course of his investigation.
Two methods are recommended for obtaining young seed oysters. These are outlined as follows:
3.5.1 Method A
The first method is dependent upon the natural reproduction of local adult oysters for the supply of young seed oysters. These are collected during spawning season by setting out collectors on which the spat or young oysters settle after their swimming period. These collectors, with the young oysters attached to them, are then placed in trays which are suspended from floating rafts or strung on wires from longlines or racks where they remain until the oysters reach marketable size.
The principal disadvantage of the method in this particular instance is the relatively slow rate of growth of the local oyster (Ostrea cucullata)1 which is reported to take about five years to reach a marketable size; although under the modern rearing techniques as suggested in this report this period may be considerably reduced.
3.5.2 Method B
The second method applies one of the most recent advances in oyster culture, that of importing hatchery-produced, young, free seed oysters.
This free oyster seed is placed directly into trays which are suspended from floating rafts, and the young oysters continue to grow until they reach marketable size.
This simplified method eliminates the necessity of depending upon the uncertainties of natural production as well as considerably reducing the labour and expense involved, as construction and maintenance of collectors is not required. Both of these methods (A and B) can be carried out at the same time and in the same areas. Rafts and trays of the same size are used for both methods and the maintenance and surveillance requirement are similar.
3.5.3 A plan of operations and a proposed time schedule with cost estimates and staffing for the project are recommended. A few notes on the biology of oysters should be included but only as applicable in clarifying details of the proposed pilot scheme operations.
3.5.4 It is recommended that one international expert in shellfish culture be appointed. He should have the necessary professional qualifications as well as experience and/or knowledge of the most recent methods and techniques of oyster rearing. A government fisheries officer with biological/fisheries training should act as a counterpart, learn methods and techniques developed by the expert in order to continue the project when the expert has completed his assignment.
Four semi-skilled labourers are also needed. These men are required to construct the rafts, longlines, trays, etc. as almost all the equipment must be built by hand on the site. They are also required to assist the expert and fisheries officer in the daily maintenance and operation and other related duties. In addition, a fisherman/boat man should be appointed being qualified to splice rope, mend nets, etc., operate an outboard motor and assist in operations and maintenance when required.
