WO2014204409A1

WO2014204409A1 - Apparatus for rearing marine organisms

Info

Publication number: WO2014204409A1
Application number: PCT/SG2014/000296
Authority: WO
Inventors: Kok Hong TOH
Original assignee: Toh Kok Hong
Priority date: 2013-06-20
Filing date: 2014-06-20
Publication date: 2014-12-24

Abstract

An apparatus for rearing marine organisms comprising a flexible sheet, a first portion of the flexible sheet defining an enclosure for holding the marine organisms and a conveyor for the flexible sheet to be slidably attached thereon; the conveyor operable to clean and dry a second portion of the flexible sheet while simultaneously releasing a third portion of flexible sheet back to the enclosure.

Description

APPARATUS FOR REARING MARINE ORGANISMS FIELD OF THE INVENTIO

The present invention relates to an apparatus suitable for, but not limited to, rearing and growing young marine organisms such as fish fingerlings and/or larvae of cultivated crustaceans like prawns and crabs etc.

BACKGROUND ART

Conventional farming or rearing of marine organisms such as fish fingerlings at the early stage of hatchery typically uses an open pond or tank system.

The open pond system is relatively simple to implement and deploy but a disadvantage is that such open space system is subjected to the force of nature and often lacks proper control in cleaning, disease control and culling which may result in injury or death of fish fries due to lack of hygiene, existence of predators or parasites.

The tank system is a closed system which typically is an enclosed cement or fibre-glass tank. Such a closed system prevents undesirable predators or parasites to some degree but due to lack of a regular flow of water, water pollution due to a build up of bio-waste and algae; and resultant disease outbreak are likely to happen unless regular cleaning or change of water is scheduled. Effective cleaning and water change, however, poses a hazard to the young fish fries because such cleaning and water changing exercises often require physically removing the fries from the tank prior to water changing and cleaning. Such removal often hurt the young fries due to their delicate and partially formed skin without the protective scales, thereby resulting in high mortality and disease outbreak.

Another method is rearing the eggs and larvae in a water-proof bag suspended in a body of water in ponds or sheltered coastal water. However water pollution due to a build up of bio-waste and algae; and difficulty in effective water change within the water-proof bag may still result in disease outbreak.

Patent publication W01986004780 describes a method for the exchange of netting under the fish using a reel netting so that a clean reel netting may be inserted without moving the fish. However, such reel netting, while partially addressing the above problem of cleaning, does not effectively protect the fish from predators and parasites. In addition, the reel netting of W01986004780 appears to be more suited for cultivation of larger marine organisms rather than small fish fries.

Another drawback associated with the prior art reel netting is the inability to sort the marine organisms such as fish fingerlings according to their size or to perform culling of the marine organisms.

The present invention seeks to provide an apparatus that alleviates the above mentioned drawbacks at least in part.

SUMMARY OF THE INVENTION

The invention was developed to overcome the difficulties related to near- complete water change, easy cleaning of the enclosure and minimal or no handling of the organisms within. These will lower the mortality related to disease outbreak and stress due to the handling of the marine organisms.

The present invention is further designed to enable eggs, larvae and fries to develop in a single enclosure for the entire period, with effective water change, cleaning and culling with minimal manual/physical handling of the young marine organisms such as fish fries.

The present invention further incorporates a water-proof material instead of netting in order to prevent the introduction of predators and parasites. Also the presence of one-way valves and sieves to ensure control of water exchange as well as concentrating the fries as a dirty section shortens during the cleaning process enable culling to be performed. The present invention is primarily suited for small organisms (larvae and fries), but may be used for larger organisms or mature marine organisms as well.

In accordance with an aspect of the invention there is an apparatus for rearing marine organisms comprising a flexible sheet, a first portion of the flexible sheet defining an enclosure for holding the marine organisms and a conveyor for the flexible sheet to be slidably attached thereon; the conveyor operable to clean and dry a second portion of the flexible sheet while simultaneously releasing a third portion of flexible sheet back to the enclosure.

Preferably, the conveyor comprises a frame shaped and sized to allow the second portion of the flexible sheet to be spread thereon for cleaning and drying.

Preferably, the flexible sheet is a water-proof tarpaulin sheet.

Preferably, the total length of the flexible sheet is more than double the length of the first portion of the flexible sheet defining the enclosure.

Preferably, the width of the flexible sheet includes the width of the enclosure as well as double the depth and section above water.

Preferably, the conveyor comprises a pair of horizontal beams defining the width of the enclosure.

Preferably one length of the flexible sheet is slidably attached to each horizontal beam via a plurality of attachment means to define the enclosure.

Preferably the flexible sheet is attached to a sliding mechanism to facilitate cleaning and drying of the flexible sheet without manual removal of the marine organisms. Preferably the sliding mechanism comprises sliding tracks or guides affixed on the horizontal beams.

Preferably the flexible sheet is supported on the sliding mechanism via attachment means that move along the sliding tracks or guides, the attachment means and guiding tracks allowing the flexible sheet to be slided out along its length.

Preferably the enclosure comprises a first segment and a second segment separated by a movable barrier.

Preferably the movable barrier is formed by raising or lowering a portion of the flexible sheet with respect to the water level of a water body.

Preferably in operation the portion of the flexible sheet belonging to the first segment is cleaned while simultaneously, the portion of the cleaned and dried flexible sheet belonging to the second segment is pulled into the water.

Preferably clean water is pumped into the second segment.

Preferably the frame is circular and configured to rotate on its central axis driven manually or by a motor at a speed matching the speed at which the flexible sheet is pulled out of water for cleaning and drying.

Preferably, the apparatus comprises pipes to pump clean water in or dirty water out of the enclosure.

Preferably, the apparatus comprises sieves of varying pore sizes placed over the outlets of the pipes.

Preferably the third portion of the flexible sheet is cleaned and dried. In accordance with another aspect of the invention there is a method for cleaning an enclosure for rearing marine organisms, the enclosure formed by a first portion of a flexible sheet slidably attached to a conveyor comprising the step of sliding a second portion of the flexible sheet along the conveyor for cleaning and drying; wherein the sliding step is simultaneously accompanied by a third portion of the flexible sheet being released back to the enclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 is a side perspective view of the apparatus for rearing young marine organisms;

Fig. 2 is an end view of the apparatus of Fig. 1 from the direction A;

Fig. 3 is a top view of the apparatus of Fig. 1 from the direction B;

Other arrangements of the invention are possible and, consequently, the accompanying drawings are not to be understood as superseding the generality of the preceding description of the invention.

PREFERRED E BODIMENT(S) OF THE INVENTION

In accordance with an embodiment of the present invention there is an apparatus 10 for rearing marine organisms and in particular (but not limited to), young marine organisms such as fish fries. Apparatus 10 comprises an enclosure 12 for containing marine organisms such as fish fries. Enclosure 12 is formed by a portion of a flexible sheet 14 which may be water-proof. The formed enclosure 12 is thus a water-proof bag. The water-proof material may be tarpaulin. To form the water-proof bag, the flexible sheet 14 may be supported using a pair of horizontal beams 16, the space in between the pair of horizontal beams 16 defining the width of the enclosure 12. Each horizontal beam 16 may in turn be supported by a plurality of vertical beams 18. Each vertical beam 18 is suitably disposed at intervals from its adjacent beam 18 to provide adequate support to the horizontal beams 16. In addition, portions of the flexible sheet 14 may be secured to the vertical beam 18 (for example via tying), to prevent excessive movement of the tarpaulin 14 due to waves or tides, if desired.

As illustrated in Fig. 1 and 2, the apparatus 10 may be installed in a water area 20. Water area 20 may be a large pond or open sea. In these examples, the vertical columns/beams 18 may be suitably driven into the pond bottom 22, or may be suitably attached to a floating platform out at open sea.

Each horizontal beam 16 is attached to the vertical columns 18 or a floating platform out at open sea and may be positioned at a height slightly above water.

To form the enclosure, the flexible sheet 14 comprises one length of the flexible sheet slidably attached to a horizontal beam 16a via a plurality of attachment means 24a and the other length of the sheet attached to the other horizontal beam 16b via a plurality of attachment means 24b to define the enclosure 12 there-between. In this way, the enclosure 12 may thus be envisaged as a water-proof bag for holding the marine organisms.

The length of the water-proof bag is designed to be more than double the length that is used to contain the marine organisms so that at any one time, half of the water-proof bag is above water, cleansed, dried and ready to be lowered into the water for the next water change cycle.

The width of the water-proof bag would include the width of the enclosure as well as double the depth and section above the water so that the water-proof sheet forms the bottom as well as both sides above and below the water level as a continuous sheet.

The apparatus 10 further comprises cleaning and drying frames 40 positioned on the bank of the water area 20. The cleaning and drying frames 40 may be extensions from the horizontal beams 16. The flexible sheet 14 is preferably attached to a sliding mechanism to facilitate cleaning and drying of the same without the need for manual removal of the fish fries.

Sliding mechanism comprises sliding tracks or guides 26 affixed on the horizontal beams 16. The formed water-proof bag 14 is suspended/supported on both sides by attachments means 24a, 24b that move along guiding tracks 26 disposed on the horizontal beams 16. The attachments 24a, 24b and guiding tracks 26 allow the bag to be slided out along its length so as to define the two segments 32 and 34. The dirtied segment 32 may be pulled out of the water and cleaned while simultaneously, a similar length of clean bag 34 is being pulled into the water and filled with clean water to receive marine organisms.

The volume of water within the enclosure 12 is separated into the dirtied segment 32 and a clean segment 34 by means of a barrier 36. The apparatus 10 is operable such that the dirtied segment 32 and clean segment 34 may change over time. This may be achieved by using a movable barrier 36. Movable barrier 36 is formed by raising or lowering a portion of the water-proof sheet 14 with respect to the water level of the pond or water body. The movable barrier segment 36 of the bag 14 between the dirty and clean section is elevated above water level to separate the two segments 32, 34 so that dirty water from the dirtied segment 32 is not allowed to flow into the clean segment 34 to pollute or contaminate the clean water.

The guiding track 26 may be constructed via a double V-shaped configuration (not shown) on which a carriage is mounted. The carriage is mounted on the V track by means of a plurality of bearings (example four bearings) in two rows on both sides of the V edge to provide stability. Use of a bogie carriage may be necessary if there are S or curve segments of differing radii. On the carriage is preferably connected with biasing means such as spring which in turn holds up the side of the tarpaulin sheet preferably by means of eyelets 15 made in the sheet 14.

The guiding tracks 26 comprises slides which are joined together to the required length and configuration with straight and curve slide segments extending into the cleaning and drying frames 40. The cleaning and drying frames 40 preferably have a circular surface (thus requiring the curve segments) hence maximizing the spreading of the length of sheet 14 around the circumference of the frames 40 while saving valuable land space. The spreading of sheet 14 around frames 40 is to facilitate cleaning and drying of the same.

The circular frame 40 may be configured to rotate on its central axis driven by a motor at a speed that would match the shortening of the dirtied segment 32 of the sheet.

Large pipes may be built along both ends of the water body or pond 20 to pump clean water in or pump dirty water out of the enclosure 14. Placed over the outlets where water is pumped out are sieves of varying pore sizes which can be plugged in and out over the outlet pipes so that they can be changed as the fish fries become larger and stronger. Initially of a smaller size, the sieves are installed to prevent marine organisms from being pumped out together with the dirty water.

In operation, mechanical drivers such as winches are deployed to pull the water-bag 14. Winches may be placed on both sides of the bag 14 to slowly winch out the water-proof sheet 14. The slide mechanism allows the sheet 14 to be pulled out at a controllable rate so that there is enough time for the dirty water to be pump out through the sieves without raising the water level inside the bag 14. This would minimize stress on the bag, attachments and the guiding tracks. As an example, with a bag of size 30 metres (length) x 10 metres (breath) x 2 metres (depth), containing 600,000 litres of water, if the bag is completely pulled out of the water over 8 hours, it would have to move at 6.2 centimetres per min. along its length. The water flow through the sieves would be at a rate of 1 ,200 litres per min. It is to be appreciated that the rate of movement of the sheet/bag is carefully determined so that it should not exert significant force on the bag, attachments and guiding tracks that could lead to tears on the bag, breakage of the attachments or malalignment of the tracks. The rate over a wide surface area would also minimize stress on the fries as they are gradually concentrated at one end. The whole process can be initiated by a timer for example, at 0500 hrs in the morning and the process completed by 1300 hrs in the afternoon. If the process is fully mechanized no human intervention is necessary until the last few meters to lower the movable barrier and allow the marine organisms concentrated at the dirtied section to swim across.

Cleaning of the sheets spread out on the circular frame 40 may be performed with water jet array. A row of water jets is placed across the segment of dirty water-proof sheet which have been pull out of the water and are used to clean the sheet. The sheet is then exposed to direct sunlight and rain to allow any remaining organisms on the sheet to be further cleansed, destroyed. It is then ready to be pulled back into the water in the opposite direction to start the water exchange process when the water in the enclosure needs changing.

The clean water supply may be pumped into the clean segment 34 by filtering water from a settling reservoir pond through for example, sand filters before pumping into the clean segment 34. The filtering process should remove all potential predators like small fishes and larger crustaceans as well as parasites that could infect the fries. The clean water supply is preferably configured to provide between 1000-1500 litres of water per minute.

The tracks, rails or cables that are used to provide guidance and traction to the moving of the tarpaulin enclosure are secured to the supporting horizontal beams 16. The rails on both sides of the tarpaulin enclosure 14 are preferably substantially parallel to each other to ensure proper retraction, extraction of both sides of the enclosure 12.

The apparatus 10 will next be described in the context of its operation. As an example scenario, the apparatus 10 is installed, and the enclosure 12 contains the marine organism as formed by a first portion of the flexible water-proof sheet 14.

The sliding mechanism, together with the drying frames 40, form a conveyor to move a second portion of the flexible water-proof sheet 14 out of water for cleaning and drying. As the second portion of the flexible water-proof sheet 14 moves, a third portion of cleaned and dried flexible sheet is simultaneously released back into the water (the third portion may not be utilized before). It is to be appreciated that the terms 'first', 'second' and 'third' portions are used for illustrative purpose to differentiate one portion of the water-proof sheet 14 from another during operation, and are not meant to be restrictive in terms of order or priority.

It is to be appreciated that the winching action which effectively rotates the two frames 40 simultaneously (i.) pulls in dirtied sheet 14 (the second portion) from the water for cleaning and drying and (ii.) discharge cleaned and dried sheet 14 (third portion) into the water, much like a conveyor beltlike system.

The apparatus 10 may be used for different stages of the growth of a marine organism as follows:- a) During the first 2-3 weeks, as the eggs hatch and the larvae develop, there is no necessity for water change or cleaning as any biomass or waste generated by the larvae is very small relative to the overall volume of the enclosure. The size of the enclosure 12 is designed to be able to rear the fries from eggs to fingerlings of sellable sizes. b) When water change and the cleaning of enclosure 12 are necessary, the end of the enclosure 12 that is at the far side of the working winch for pulling the water-proof bag is elevated above the water level by means of a rope or rigid pipe to define the movable barrier segment 36. The winch at the other end starts the process of pulling the sheet 14 and the sheet 14 that was dry and above water spreads around the frame 40 as it is slowly pulled onto the water. The rope or pipe that holds the sheet 14 above water forming the movable barrier segment 36 divides the clean section 34 from the dirty section 32. The water from the dirty section is prevented from crossing or entering the clean section by the elevated barrier segment 36. The water from the dirty section 32 is pumped out using outlet pump (not shown) and this section becomes progressively shortened as the winch starts to winch in the dirtied portion of the sheet 14 for cleaning and drying. The fries are prevented from being sucking out of the enclosure by the sieves as described earlier. Concurrently, clean filtered water is pumped into the clean section 34 that is pulled into the enclosure 12. c) As the dirty section 32 is slowly shortened (due in part to sheet 14 being pulled for cleaning and drying and sheet 14 being placed in water after cleaning and drying), the fries are being concentrated together very slowly and this would greatly reduce the stress during each water change. It may become necessary to increase aeration in the shortened section as the fries grow larger to support a heavier biomass. d) Once the fries are very concentrated together as the dirty section shortens, the winching can stop temporary and the rope that elevated the two section is lowered forming a water channel between the two sections. Once fries start to swim across from one section to the other, the whole school will quickly follow and most will enter the clean section 34 completely unhandled. This is advantageous as it avoids the use of manual handling of young fries which may injure them due to their unformed scales. A culling contraption can also be placed in between the two sections so that the fries swim into and are channelled through culling gates of various sizes. This will separate the smaller and larger fries and allow the majority average size fries to swim into the clean section. e) The winching continues until almost all the dirty section 32 is out and whatever remaining fries and dirty sediments are allowed to enter or drain into the clean section 34. Even with this, water contamination would still be minimal as the dirty water is diluted by a much larger volume of clean water. f) As the dirty section 32 of the sheet 14 is winched out of the water, it is sprayed clean with power jets. This could be done manually or automated by an array of fixed water jets. g) Once cleaned, the sheet 14 above water is spread out on the frame to dry and sun over the circular frame 40. This further reduces or kills off whatever micro or bacterial organisms that were not washed off earlier. If the circular frame 40 is to be used on another enclosure, the sheet is folded in a way to allow it to be pulled smoothly into the water in the opposite direction on the next water change.

The following are further considerations to ensure proper and smooth operation of the apparatus 10.

The slide sections may be joined together with joint blocks and the ends are smoothened by filing for the reduction of friction. A carriage is run over the joints to ensure that it does not get stuck.

The tarpaulin sheet 14 is attached to the rails on both sides by attachments. It would be useful to incorporate a biasing means, such as a spring acting as a dampener within the attachments to avoid sudden jerks to the tarpaulin eyelets that could tear the water-proof material/sheet 14. Preferably, pressure devices along some of the attachments may be installed that would automatically stop the winching i.e. pulling of the tarpaulin sheet 14 and will activate an alarm once the system exceeds a certain strain as the same may indicate jam carriage or sieve blockage.

The leading edge of the tarpaulin sheet 14 is held above water as the winch on the far side pulls the enclosure from the edge of the pond onto the water. This is to prevent the introduction of unfiltered water from getting into the enclosure. At the same time filtered water is pumped into the enclosure as the entire length is slowly introduced and filled.

The attachment means 24a, 24b form part of the sliding mechanism for adjustment of the tarpaulin sheet 14 so that at any one time, approximately half of the tarpaulin sheet 14 is above water, cleansed, dried and ready to be lowered into the water until the next time it is to be cleansed and dried.

The advantages of the invention are listed as follows:-

The enclosure formed is movable and portions could be easily removed from the water and cleaned without manual handling of the young marine organisms. Overtime and through a 'conveyer belt' (the movement of at least one portion of the flexible water-proof sheet 14 laterally across the water for cleaning of the sheet) or 'curtain' process (the movement of the flexible waterproof sheet 14 to form a barrier segment for facilitating the input of clean water and removal of dirty water), a minimum standard of cleanliness of the enclosure is maintained.

The use of water-proof sheet or tarpaulin sheet controls the quality of the water that is essential for the cultivation of larvae and fries. The removal of predators, parasites and bio-waste by filtering reduces infection of the cultivated organisms.

Almost complete water change may be achieved such that both the solid and soluble bio-wastes can be substantially removed. In contrast, rigid frame enclosures can only allow partial water change without removing the fries, resulting in recurring water pollution as well as bacteria multiplication. This allows much denser farming to be carried out and increases the yield of larvae and fries.

It is to be understood that the above embodiments have been provided only by way of exemplification of this invention, such as those detailed below, and that further modifications and improvements thereto, as would be apparent to persons skilled in the relevant art, are deemed to fall within the broad scope and ambit of the present invention described:-

• The enclosure may be installed in sheltered coastal waters. In this case the guiding tracks can be fixed on the sides of the floating platform.

• Instead of pumping dirty water out, the dirty water can flow out through sieves with one way valves incorporated into the tarpaulin sheet 14 during construction. As the dirty section shortens during winching the water will flow out through the one-way valves into the sea. There will be greater stress on the tracks and tarpaulin sheet but saving of energy and equipment.

It is to be further appreciated that features from one or more embodiments as described may be combined to form further embodiments without departing from the scope of the present invention.

Claims

The Claims Defining the Invention are as Follows:

1. An apparatus for rearing marine organisms comprising a flexible sheet, a first portion of the flexible sheet defining an enclosure for holding the marine organisms and a conveyor for the flexible sheet to be slidably attached thereon; the conveyor operable to clean and dry a second portion of the flexible sheet while simultaneously releasing a third portion of flexible sheet back to the enclosure.

2. The apparatus according to claim 1 , wherein the conveyor comprises a frame shaped and sized to allow the second portion of the flexible sheet to be spread thereon for cleaning and drying.

3. The apparatus according to claim 1 or 2 wherein the flexible sheet is a water-proof tarpaulin sheet.

4. The apparatus according to any one of the preceding claims wherein the total length of the flexible sheet is more than double the length of the first portion of the flexible sheet defining the enclosure.

5. The apparatus according to any one of the preceding claims wherein the width of the flexible sheet includes the width of the enclosure as well as double the depth and section above water.

6. The apparatus according to any one of the preceding claims wherein the conveyor comprises a pair of horizontal beams defining the width of the enclosure.

7. The apparatus according to claim 6 wherein one length of the flexible sheet is slidably attached to each horizontal beam via a plurality of attachment means to define the enclosure.

8. The apparatus according to claims 6 or 7 wherein the flexible sheet is attached to a sliding mechanism to facilitate cleaning and drying of the flexible sheet without manual removal of the marine organisms.

9. The apparatus according to claim 8 wherein the sliding mechanism comprises sliding tracks or guides affixed on the horizontal beams.

10. The apparatus according to claim 9 wherein the flexible sheet is supported on the sliding mechanism via attachment means that move along the sliding tracks or guides, the attachment means and guiding tracks allowing the flexible sheet to be slided out along its length.

1 . The apparatus according to any one of the preceding claims wherein the enclosure comprises a first segment and a second segment separated by a movable barrier.

12. The apparatus according to claim 11 wherein the movable barrier is formed by raising or lowering a portion of the flexible sheet with respect to the water level of a water body.

13. The apparatus according to claim 11 or 12, wherein in operation the portion of the flexible sheet belonging to the first segment is cleaned while simultaneously, the portion of the cleaned and dried flexible sheet belonging to the second segment is pulled into the water.

14. The apparatus according to claim 13, wherein clean water is pumped into the second segment.

15. The apparatus according to claim 2 and 11 wherein the frame is circular and configured to rotate on its central axis driven manually or by a motor at a speed matching the speed of movement of the first portion of the flexible sheet.

16. The apparatus according to any of the preceding claims comprising pipes to pump clean water in or dirty water out of the enclosure.

17. The apparatus according to claim 18 comprising sieves of varying pore sizes placed over the outlets of the pipes.

18. The apparatus according to any one of the preceding claims, wherein the third portion of the flexible sheet is cleaned and dried.

19. A method for cleaning an enclosure for rearing marine organisms, the enclosure formed by a first portion of a flexible sheet slidably attached to a conveyor comprising the step of sliding a second portion of the flexible sheet along the conveyor for cleaning and drying; wherein the sliding step is simultaneously accompanied by a third portion of the flexible sheet being released back to the enclosure.