1. Inventor- Timothy John Kiely MUD METHOD OF FARMING PEARL PRODUCING OYSTERS Field of invention The present invention relates generally to, but not limited to, a method of growing and farming salt water pearl producing oyster shells. The invention has particular, although by no means exclusive application to the cultivation and fanning of salt water oysters for pearl production. Abstract. The invention is the utilisation of two aspects which when used together prevents or substantially reduces the growth of undesirable fouling on the oyster shell. One aspect is the system utilises waters with suitable and sufficient mud particles suspended in it. The second aspect is the horizontal positioning of the oysters. This allows the mud particles to settle on the shell forming a protective layer that discourages the settlement and subsequent growth of undesirable fouling, including but not limited to, seaweeds, sponges and other molluscs such as, but not limited to, barnacles. Anyone familiar with salt water pearl production would be aware of the problem of fouling of shell and associated housings. Background of the Invention There have been many systems used for the farming of salt water pearl producing oysters. The most common still in use today are the Surface Long line system and the Raft system. The shells are hung in their housing from these surface structures. These systems are useful because they keep the oysters near the surface. There can be more food nearer the surface because of more light which the plankton need, as the plankton is the major food source for oysters. With more food the oysters can be generally healthier and grow faster. This improves the chances of producing a larger quality pearl in a shorter amount of time. Another advantage of surface systems is the easy access to the oysters. This is an advantage for inspection activities and becomes very important for the cleaning maintenance of the oysters and their housing apparatus.
2. Especially in the top upper levels of the water column, the amount of other organisms is also greatly increased, and these settle and grow on the shell, their associated housing and supporting surface structures. The shell are commonly housed in a flat panel made of a plastic coated steel frame with double plastic mesh coverings, sewn to make individual pockets for commonly 6 or 8 oysters for mature shells per panel. This type should be well known to anyone with knowledge of the pearl oyster culture. The shells hanging from Long-lines and rafts in these panels keep the oyster shells in a vertical aspect. Shells are sometimes housed in cages of individual pockets, commonly from rafts. The housed oysters are in a horizontal aspect, mostly temporarily after nuclei seeding before being transferred to the panel system on surface long lines. These systems are usually used in relatively clean waters environments and there is no likely-hood of sufficient mud settlement on the shell when housed in the horizontal cages. The substantial structure of the cages promotes fouling growth and must be cleaned regularly. Other systems also used include bottom systems, but have been mostly abandoned in favour of the surface systems. These have included a variety of apparatus including tent-like structures, steel posts, fences, and raised beds or just laying on the bottom. These structures were generally designed to keep the shell off the bottom where they may be prone to being smothered with shifting seabed material such as sand, grit and mud. The shells are also more prone to attack by bottom dwelling parasites. Shells just laid on the bottom are also more prone to be lost. Problems with bottom systems like these also include the fact is they are still prone to fouling growth on the shells which must be cleaned and this usually means a substantial amount of diver time, which is a costly, slow and inefficient method. The growth offouling on the oysters and their housing has the unwanted effect of restricting the flow of water containing the nutrition the oyster needs for good growth. This is accentuated near the surface because of the extra light increasing weed type fouling growth. This results in the starving of the oysters as the fouling restricts the flow of nutrient carrying water to the oyster. Such restrictions offood, oxygen and other nutrients can adversely affect the health 3. of the oyster and may result in mortality. Also with reduced health of the oyster in general, it also adversely affects the oyster in its ability grow and to produce a pearl of good quality and size. Subsequently the oysters and their housing apparatus must be regularly cleaned, for example, maybe every 4 weeks depending on the farm location and time of year. This is a major activity, and one of the most expensive activities on a pearl farm as it is very labour intensive. It is usually undertaken by special cleaning vessels using high pressure water jets to blast away the fouling, and hand chipping of barnacle and other hard mollusc growths. The cleaning activity also puts considerable stress on the oyster which can result in mortality or suppression of the growth activity while the oyster settles from the shock and stress of cleaning. One destructive fouling is a type of shell eating sponge, which eats away the shell in a honeycomb fashion and may eventually lead to the death of the oyster, or severely impede the shells health, and subsequently to produce a good pearl. Some pearl farm locations have particularly severe problems with barnacle fouling which makes cleaning more difficult as the high pressure water cannot dislodge the attached barnacle and must be chipped off by hand. PRIOR ART It has been experimented with the growing of oysters in mud environments because it is known the nutrient level can be high in such environments, such as but not limited to, mangrove areas. Where oysters have been suspended above the mud bottom in any of the prior mentioned systems, (to alleviate the problem of oysters burying in the mud,) the oysters have been hung either individually or in panels in a generally vertical aspect, and have been subject to a very high degree of fouling, especially by other settling molluscs such as barnacles, which are a difficult fouling to remove.
4. Because of this problem very little effort has been made in farming salt water oysters in muddy areas, although existing farms may be near mud bottom areas, and the water has some turbidity from mud. Long-line systems with the shells placed in panels and hung so the shell is in a vertical aspect is the system of choice, and insufficient mud settlement occurs on the vertical shell to prevent fouling. To prevent fouling it has been experimented coating the shell with different chemical agents mixed in a coating base, including chemicals similar to those used on boat hulls as anti-fouling paints. However the toxicity of those chemicals can be detrimental to the host shell. If copper based it is directly toxic to the oyster, and other agents such as Tri-butyl Tin can alter the sexual orientation of the shell and also produce thinner shells and pearls. When shell eating sponges are encountered the cleaned shell must be given a poison coating to kill the remaining sponge after cleaning. Another system used involves the coating of the shells and their housing in wax. This involves melting wax to liquid and dipping the panel and shells into the wax. As the wax cools it leaves a thin coating. This system is cumbersome and expensive. Also the system seems to be only of reasonable benifit with the prevention of settlement of weed type fouling. Barnacle settlement does not seem to be halted by an advantageous amount, rendering the treatment inefficient. Sometimes the shells are places flat on stable bottom surfaces which prevent the burying of the oyster from shifting sands. Fouling on the top of the shell occurs and the shells are periodically turned over, exposing a clean side and generally slowly killing most of the fouling on the underside. This involves considerable dive time and is not efficient. Currently the pearl industry's most common system of farming and cleaning oysters is by the Surface Long-line system and the regular high pressure water cleaning, combined with the hand chipping of harder to remove fouling such as barnacles and other molluscs. This is also conducted in generally clean water with little mud particle content.
5. GENERAL DISCLOSURE OF INVENTION The invention generally provides for a system/method of farming salt water oysters, including but not limited to pearl producing oysters, in such a manner that there is limited or no need to clean the oysters of the fouling growth normally associated with pearl shell farming. One aspect of the invention involves growing the oysters in waters that have a suitable amount of mud type particles suspended in the water and shall from here on may be referred to as "muddy water" or "turbid water". The amount of mud particles in the water may vary, the critical factor is that the environment must have sufficient to allow the advantage of the next aspect of the invention to take place. The second aspect is that the pearl oysters grown in the muddy water are laid flat in a horizontal manner, allowing the mud particles to settle on the shell surface. Because pearl producing oysters are of a generally physically flat nature, when the oyster is laid flat in a muddy water environment the mud particles will settle on the surface of the shell forming a mud film. This film can vary in thickness, commonly, but not limited to, Imm to 10mm. A layer or film of mud has the effect of discouraging the settlement and subsequent attachment of plant and animal plankton varieties, including but not limited to, barnacles and seaweeds, which are drifting through the water column chancing for contact with a suitable material to attach itself to and then grow. Mud is not a suitable material for attachment and even though the shell strata/material immediately below the mud layer is a very favourable attachment material, the immediate contact with the mud masks its presence, and the plankton types continues to drift. The result of these factors is that the oysters remain free from fouling and may feed unimpeded as the mud layer does not obstruct the feeding function. (The oyster has its own mechanism to clear particle build-up around its opening, by quickly closing itself, thus causing a puff of water which blows away build-up of sediment material from its lip area.) 6. The oysters may be set in the muddy water column in a variety of ways including but not limited to the following systems. 1. The individual oysters may be laid free on the suitable mud type bottom in a flat manner. 2. More practical commercial operations may involve but not limited to a system of flat panels that may be individually laid directly on the suitable mud type bottom horizontally. 3. The panels of shells may be raised off the suitable mud type bottom as an individual panel in a horizontal aspect. 4. The panels of shells may be stacked in a multi layered horizontal rack system, with suitable space between the panels to allow adequate water flow. The dimension of the individual panel and/or multi-layered rack system are not limited in size, however the infrastructure and equipment of the individual pearl farmer may provide limits to the dimensions of the panels, and the numbers used in a rack system, to a size that is practical for the farm size and available equipment. A long-line system can be utilised where each panel or rack block system is attached to each other by a continuous line and buoyed at each end. Alternatively layered rack blocks may be individually buoyed to the surface which may be suitable in a large layered rack system. Alternatively to being marked by a buoy, the systems may have no surface markers, and may be marked by an alternative navigation and positioning systems, including but not limited to, electronic marking such as Global Positioning System. The "out of sight" bottom system can also provide better security against theft, and a "non-visual marker system" improves security even more. Pearl farming in areas such as Indonesia is very prone to theft and farms must use substantial security systems.
7. Any system may be incorporated as long as the two disclosure aspects are jointly incorporated. That the oysters are laid in a horizontal manner allowing for the settlement of a mud layer, and that the waters have sufficient mud particles to allow the settlement of the mud onto the shell surface. The panel can be made of, but not limited to, a flat steel wire and plastic frame similar to that used in current panel production, that anyone familiar to the art of pearl farming will be aware of. The frame is then covered with a plastic or wire mesh on which the oysters will lay flat. A second layer of mesh may or may not be laid over the oyster, creating an overall security blanket, or sewed to create individual pocket housings for the oyster shells. The panels or rack system with shells laid in place is then lowered into the muddy water and onto the bottom. It then begins to collect a mud layer membrane on the shell surface. The rough texture of the surface of the shell encourages the collection and settlement of mud particles. The structure supporting the shell may alternatively be totally suspended and supported from the surface so there is no physical contact with the bottom. This layer of mud then prevents major settlement of fouling organisms including but not limited to other molluscs (including barnacles), seaweeds and sponges. There is little or no maintenance needed for cleaning, and the shells may remain undisturbed until harvest, or other routine farming procedures such as x-ray examination, security or general health check. The system incorporating the two basic aspects would account for considerable cost savings, and the shells should be in a reasonable nutritional environment to help enable the best chance for good pearl production. To be able to leave the oysters less disturbed by cleaning also has the effect of creating less stress for the oyster, allowing the oysters to grow in a more even manner.
9. DRAWINGS. Attached are 9 (3 pages) drawings with itemised details. Please note that the drawings are examples of the basic functionality of the system in how it works. It should not be inferred that the utilisation of the disclosed aspects of the invention, being the situating the shell in a muddy turbid water in a basically horizontal manner to allow the settlement of a mud layer on the shell, is limited to the designs inferred in the drawings. Because of this factor there are no dimensions offered for panel or multi layered rack system dimensions.