Lau Fau Shan's 700 years old oyster industry is facing the problem of ageing workforce, with the number of oyster growers significantly reduced from 700 people in the 60s to 100 people nowadays. Most of the Hong Kong oyster farmers are still using an inefficient cultivation method that are invented more than half a century ago. These traditional oyster reef culturing methods are time and labour intensive.
Oyster raft culture became popular in the 1980s and is still a technique that is commonly used in Hong Kong's oyster breeding culture. Oyster larvae are grown in the process of seed production, which can be artificially done in indoor larval tanks or capture from the wild with shell clutch hung from longlines in the sea. Lots of preparation work have to be carried out in either methods;
- Indoor Seed Production Hatchery (with Larval Tanks and Spat Culture) Although the indoor seed production hatchery process can hugely improve the fertility rate of oyster larvae, a large indoor space is needed for carrying out the oyster larvae hatchery process, where the larval tanks and spat culture will be under great care and closely monitored by oyster farmers.
- Seed Production with Wild Capturing Method (with Shell Clutch) In the wild capturing method, larvae are naturally captured with artificial or organic media such as shell clutch or bag in strings that are hung with longlines along the coast. The rate of larvae being successfully captured in wild is not guaranteed and is relatively low with this method, as there are a lot of uncontrolled variables affecting oyster larvae's ability of attaching to the shell clutch or bags floating in the sea.
- As different stages of oysters have to be grown in different stations floating in the sea, oyster farmers have to travel from station to station by boat. Oyster farmers have to travel up and down from boat as to transfer and deliver oysters in-between rafts, it can be a hard-work for the aged oyster farmers.
How can we improve the efficiency of oyster breeding along with the process of cutting down the complexity of labour-intensive oysters method?
Easy and Handy Operation
- Can we invent a system that is not as complex as the oyster growing culture as experienced in traditional oyster rafts, where different stages of oysters can be grown in one place?
Eliminate the Need of Boat Travelling as to Reach Oyster Rafts
- Is there any other way that oyster farmers can reach the oyster reef in other ways, without the need of travelling by boat?
Improve the Fertility Rate of Growing Oyster Larvae Naturally
- Is there any other way that oyster farmers can reach the oyster reef in other ways, without the need of travelling by boat?
How does your design aim to positively impact the oyster farming community?
Whole Life-Cycle of Oysters Happening in One Place
- "Smart Solar-Energized All-in-One Oyster Reef" provides an environment where oysters of different stages can be grown in one device, so the oyster farmers won't need to travel from raft to raft.
Small in Scale - Controllable
- "Smart Solar-Energized All-in-One Oyster Reef" can be easily controlled and used by oyster farmers as it is small in scale as compared with the traditional oyster reef.
No Longer A Labour-Intensive Activity
- "Smart Solar-Energized All-in-One Oyster Reef" can be operated by an oyster farmer individually without the need for group operation, which is less labour intensive compared with the traditional oyster growing culture.
Raft of High Mobility
- "Smart Solar-Energized All-in-One Oyster Reef" is highly mobile as the device can be driven by a remote controller. The device can be driven to anywhere in the sea based on the conditions of the growing oysters.
Eliminate the Need of Boat Travelling as to Reach Oyster Rafts
- "Smart Solar-Energized All-in-One Oyster Reef" frees up the oyster growing culture from the need of boat travelling that is necessary for accessing the traditional oyster rafts.
September 3, 2021
Mid-Term Presentation
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Research & Development
- What is it? What does it do?
- What are the questions this work is asking? What new knowledge are you creating?
- Is it possible for the whole life-cycle of oyster take place in one system, instead of being divided into several stations floating in the sea?
- Can we imply innovative technology into the oyster culturing industry?
- Can the oyster culturing process be less complex? Is the labour-intensive process necessary? Is there any other way to solve the labour-intensive process as demonstrated with the traditional oyster reef culture?
- How are you going to test your assumptions?
- How to maintain your device? Most of the components will be pre-fabricated and get installed together by oyster farmers. When one of the components is not working or gets worn off, it can be replaced with new one instead of buying the whole setup.
- What do you think are the strongest and the weakest points in your project now?
- What construction technique are you using?
It is a remote oyster reef that can be controlled and accessed by oyster farmers onshore, without the need of travelling by boat.
weakest point: very much relying on technology / remote control
strongest point: high mobility, easy and handy operation, eliminated the need of labour-intensive process
User, community
- Who uses it? Can you draw a particular user? Can you describe to me that user, how they look, your assumption on their backgrounds, abilities, preferences, and what drives them? The target user group of this device will be used by the oyster farmers. The device is design in the way that is easy to be used, and with improved features enhancing the efficiency in the production and harvest process of oyster.
Use
- What are the benefits users can get from the device?
- What problems does your design cause?
- How do you operate and maintain this installation?
- How do people get on board? Unlike the traditional oyster reef where people have to travel with boat and get on board of the oyster rafts, this new oyster reef prototype allows oyster farmers to remote control onshore, without the need of boat travelling.
- How much weight can you carry? As the device is relatively small in scale compare to the traditional oyster reef, it will not be able to carry loading as much as the one of traditional oyster reef. Small batches of oysters will be harvested from each module.
- How to maximum efficiency and convenience for the user Question from partner:
- is there a way that the whole life cycle of oyster can take place inside one module?
- can it be each module containing oysters of different stage and the nets can be changed inside the water instead?
- can the modules be combined into groups and driven to shore instead driven one by one?
- Are there simpler ways to achieve the objective?
- Are there other possible use for clean seawater filtered by oysters?
- How long will it be in the water? The device can be in water for the whole lifecycle of oyster, which is approximately around 2.5 - 3.5 weeks. The device can be under maintenance or replaced in the period of time between the end of one lifecycle and the start of another.
less hardwork needed in taking care of growing oysters / less labour intensive
small productive rate as the device is quite small in scale
The installation will be remote controlled - data of oysters (e.g. weight, time of growth, location) all transmit from the modulus reef back to centre on land.
It can be maintained once a year - when one module is about to get maintenanced, farmers can remote drive the module back to shore and change the parts on shore.
Health & Safety
- Is it stable? Safe? ship survivability？ Thermoplastic polyurethane has a strong tensile strength around 5076 psi, that the structure of the device will be able to withstand strong external forces as received from waves or strong water currents.
- Is the device safe and environmental friendly to the ocean The device is safe to the environment, as the materials being used are resistant to chemical and environmental hazards, without producing any contamination to the ocean. The introduction of solar panel system not only saves the oyster farmer's effort of reaching oyster reefs, but also eliminate the water and air pollution that are caused in the boat travelling process.
Materials, process, scale
- What is the scale and materials? Where and how is it built? Where do the materials come from? Where do the materials go after it’s used/broken?
- What materials would you use? Where do you source it? Once used, where does it go?
- is it recyclable？ Thermoplastic polyurethane is 100% recyclable and biodegradable in a time span of 3 to 5 years.
- How long does the project take to be complete: build, bring on site and board? The construction time of the installation can be accomplished in 1 to 2 months, from the process of buying, constructing and bring on site, as the module is small in scale and easy to be carried around.
- How to mass produce the device?
Thermoplastic polyurethane is strong plastics with high tensile strength, resistant to chemicals and environmental hazards, low water absorption and can be submerged in water for long periods. The plastics will be used to construct the frame and the core of the installation.
Each module is composed of modulus components.
Energy, Waste
- Where does the installation get its energy from? The installation will mainly get the energy from solar panel. The energy is then being stored in the remote controlling system box that is floating above the water surface.
- Is it sustainable and how? I think in general the installation is a sustainable design as it mainly gets its energy from solar panel. Alongside with the use of thermoplastic polyurethane, the materials have low harm to the environment. The device can be re-used for plenty times as the components can be replaced part by part, such that the life-time expectancy of the device will be quite long.
Ecology
- Is your installation amicable to all marine lives? The oyster growing inside this installation will mainly get the nutrients from the water, algae and kelp that are naturally growing nearby, so the device will not have much influence on the marine ecosystem.
- How does it work? Especially the biology of it? Several layers of nets or fabrics of different permeability are used to cage different stages of oysters. The highly permeable yet densely knitted net is situated in the inner core of the device, maximising the surface that is providing for the attachment of oyster larvae as produced by the adult oyster that are lying at the outer net.
- Which other species will naturally be attracted to the oyster reef there, such as crabs, fish, mussels, algae and other species?
Geography
- Where do you think this installation would be? Choose a very specific site in Hong Kong waters. Why there? Tell me the characteristics of the place: water depth, tide, current, wave, closest port, fauna and flora, people and industries nearby. The device can be placed at different water location based on the growing condition of the oysters inside the contractible net - the device can be driven to shallow water during the early growing stage of oyster larvae, and being driven further in to deeper water areas along different growing stages of oysters. The device is then driven back from the deep water to onshore when it is ready to harvest.
- Will it be influenced by the weather condition?
- Does your device perform differently when in different geographic environments(for instance, near shore, in shallow water, and in distant seawater)?
- modules for shore a, shore b, shore c have different typology
The device can be driven back to the shore when facing bad weather conditions, especially during typhoon and monsoon season.
Money
- Is it cost-effective? Although thermoplastic polyurethane (TPU) is more expensive then comparable plastics, it is still a cost-effective act after taking the advantages of using this material, as TPU is environmental friendly properties and recyclable qualities, Where the components of the device are pre-fabricated, with the parts being able to be replaced and maintained instead of replacing the whole module, it is still able to keep the cost of the device low while keeping the efficiency of culturing oysters.
- Is it possible to be mass-produced? As the components of the device are pre-fabricated, it is able to mass-produce this module and assemble multiple modules into groups in the middle of the sea like the traditional oyster reef practice.
- What is the product / outcome of this installation? Who benefits from it? What is the business model of this? Oyster farmers will be the beneficial group with this instalation:
- less labour-intensive, less hard-work needed in the oyster culturing process
- oyster larvae can be grown in a natural way with an improvement in the fertility rate of oyster larvae