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ENERGY SAVING AND CARBON REDUCTION IN FISHERIES AND AQUACULTURE
 
 
Chung-Cheng Chang, Ph.D
Professor, Department of Electrical Engineering
 Dean, Office of Library and Information Technology 
National Taiwan Ocean University
 
 
 
ABSTRACT
 
In recent years, issues such as global warming and global climate change become more obvious. To solve such issues, it needs to start from the basis, and energy saving and carbon reduction is one of the important methods. Fishery is also one of the industries that will affect the earth’s resource utilization and the impact on the environment. The promotion of energy saving and carbon reduction in fishery can reduce the impact on the earth’s environment, hence, through automated net cage aquaculture, technologies such as underwater technology, net cage technology, animated software and hardware system, sensing system, communication system and information processing system can be integrated into it. Through the setup of automated net cage aquaculture system, the production cost of fish can be reduced, and the goal of energy saving and carbon reduction can be achieved.
 
INTRODUCTION
 
Ever since the industrial revolution, the global industrial development has speeded up the advancement in technology, which in turn has enhanced the development efficiency in agriculture. Fishing and animal husbandry. The output has been greatly increased, and in the meantime, due to mass production achieved in industrial products, the earth’s resources  are used quickly. Due to the increase in availability of resources and food, the world’s population is increased rapidly too. Moreover, the number of developed and developing countries in recent 100 years has also increased gradually. Today, there are more than 40 developed countries, and more than 150 developing countries. The model of rapid development of resources on the globe has gradually created significant influence on the environment of the earth. For example, global warming has created significant change on the global weather, other problems are, for example, a hole in the ozone layer, environmental pollution, the reduction of the forest, and the over-development of hillsides. Hence, not only are the development and use of part of the earth’s resources gradually saturated or even in decline, but some of the earth’s environment are also in degradation. For example, the frequency of occurrence of the drought and flood has been greatly increased, and other problems such as mudflows and landslides and the degradation in air quality are gradually pronounced. Therefore, the international society has recognized the severity of the issue, and continuous actions are taken to reduce the impact on the environment of the earth brought about by resource and industrial development.  For example, in 1985, scientist Joseph C. et al. of Farman of British Antarctic Survey have found that the ozone layer in the atmosphere has decreased gradually, and the immediate consequence is that the proportion of ultraviolet light reaching the earth surface will increase. This will have very great impact on the ecology, hence, the international society has started to take actions to limit the use of monochlorodifluoromethane and chlorofluorocarbons. Right now, there has been a reduction in the destruction of the ozone layer.
 
However, global warming and global climate change problems are still getting more serious, and this is one of the most serious problems that the earth's environment is manually deteriorated. However, to solve such problem, it must start from the root, and this is why energy saving and carbon reduction is the most important topic to be promoted around the world. For the global fishery resource, a strong challenge is lying ahead, and the global fishery is also one industry that could affect the use of earth’s resources and the impact on the environment.  Hence, how to implement energy saving and carbon reduction in the development of fishery is also a very important job, and it can reduce its impact on the environment of the earth. 
 
DEVELOPMENT TREND OF FISHERY IN RECENT YEARS
 
As the level of living quality is enhanced, people pay more attention to their health, and fishes thus become very important food sources for people today. Due to the advancement in technology and the progress in fishery technology, massive fishing has resulted in the increase in fishes caught.  Instead, resources have decreased gradually, hence, aquaculture had gradually become one of the very important rings in fishery. However, aquaculture on land has very strong reliance on water and land resource, hence, sea aquaculture has become one very important direction to increase the fish output quantity. Fig. 1 shows the variation chart of the production quantity of global fish products in ways of fish catching and aquaculture. Fig. 2 illustrates the global fish utilization and supply data, it can be seen from this figure that the global population increases rapidly, food-fish supply from capture fisheries is also increased year by year due to the progress in fish-catching technology. However, the rate of increases saturates gradually. Due to people’s health awareness, people’s demand on the fish products is still in an increasing trend, hence, there is a rapid increase in food-fish supply from aquaculture so as to supply the demand increased due to population increase and a per capita food fish supply.  Hence, aquaculture is no doubt the future development trend in the fishery industry. Fig. 3 shows the variation chart of the fishes caught for the global aquatic aquaculture products, and from this figure, the trend is easily verified. Due to the high reliance of land-based aquaculture on the water and land resource, marine net cage aquaculture has become an important trend in fishery development. Since Taiwan has very fast fishery technology development, its fish catching technology is thus very advanced. We will explain the trends in global fishery based on Taiwan’s development history.   
 
Fig. 4 illustrates the variation of the production quantity of fishery of Taiwan in the past 20 years, which includes variations such as deep-sea, inshore, land-based aquaculture and marine net cage aquaculture. From the above data, it can be seen that for inshore fish catching, due to the assistance from technology such as fish finder and due to the massive fishing activity from fisherman, Taiwan’s inshore fishery resource shows a decline trend.  Hence, the production quantity of inshore fish catching is greatly reduced.  However, for land-based aquaculture, due to the saturation of available land, the quantity of the fishes caught shows only limited increase. Next, in the deep sea fishery part, the quantity of fishes caught shows only a slight variation around 800,000 tons.  In addition, marine aquaculture still only has small fish production quantity in Taiwan. As can be seen from Fig. 3 the supply quantity as produced from aquaculture shows great increase in recent years among the global fish products, hence, if the typhoon issue can be surmounted, the production quantity should be able to be greatly increased in this part.
 
The increase of quantity of fishes caught is usually limited by the resource, and the development trend of fishery in Taiwan can be used to know the world’s fishery trends. If the headcount and number of boat for the fish catching operation around the world continues to increase, food-fish supply from capture fisheries will get saturated gradually, too.  In the meantime, when too many boats and human resources are put into fish catching, its effectiveness will be reduced, and the consumption of energy and resource will also increase.  Hence, energy saving and carbon reduction in fishery, the efficiency of fish catching and the planning and control of boat and the headcount involved in the fishery are all very important. Moreover, as the output quantity of fish catching gets saturated like the petroleum exploration, there is still relatively large development space in the aquaculture industry, hence, the latter should be the mainstream of future fishery development. (Fig. 6).  Therefore, the energy saving and carbon reduction for aquatic product aquaculture, especially for marine net cage aquaculture, is quite important in the international fishery development history, and this part will be explained based on Taiwan’s development history. 
 
TAIWAN'S NET CAGE AQUACULTURE
 
Taiwan has started to promote ocean net cage aquaculture in Penghu area of Taiwan since 1970s. However, due to immaturity of related technologies at that time, it was still limited to small-scale culture in the inner bay area of Penghu in the 1980s. Until after 1990s, due to the disease issues of giant tiger prawns  in aquaculture and due to land subsidence caused by over-pumping of groundwater for pond aquaculture, land-based aquaculture has become more and more difficult. In addition, after rapid economic growth in Taiwan, lots of factories were set up everywhere, which resulted in massive release of wastewater and heavy metal airborne particles. Moreover, massive use of pesticides and fertilizers for agriculture and planting in recent years has resulted in the contamination of water used for the aquaculture pond. Furthermore, high aquaculture cost is also another problem. For example, when an aquaculture pond is set up, in addition to the cost of pumping of groundwater or the introduction of sea water, there are other costs such as electrical power, machinery, feedstuff and small fry that greatly raise the aquaculture cost. Moreover, due to rising costs, the water used in the aquaculture pond is usually mixed with pumped air for circulation, which usually results in high dissolved oxygen and high turbidity in the water.  Finally, the fishes caught are greatly reduced. On the other hand, due to the success in modern ocean net cage aquaculture in Japan and Norway, Taiwan government started to promote greatly the offshore net cage aquaculture of Penghu and Pingtung. 
 
Although Taiwan is geographically threatened by typhoons, yet lots of environmental conditions are quite stable. For example, ocean flow, water quality and water temperature, etc. Therefore, it is quite suitable for Taiwan to develop net cage aquaculture. If net cage aquaculture is used in offshore site, the land subsidence issue caused by over-pumping of groundwater could be avoided.  In the meantime, it can greatly reduce the cost of aquaculture farmers, and the water does not need to be replaced frequently, since it is at offshore site, the sea water will be circulated continuously. There will be no issues such as high dissolved oxygen content and high turbidity, which in turn cause great reduction in the fishes caught. Since Taiwan has very limited land resources and is surrounded by seas on its four sides, it has a quite large sea field suitable for net cage aquaculture. Hence, Taiwan government has promoted net cage aquaculture aggressively, today, certain achievements can be seen.             
Since currently the offshore net cage aquaculture of Taiwan has its environment monitored manually, the labor cost is pretty high, which is not good for the promotion of net cage aquaculture. It is needed to develop architecture and technology for automated net cage aquaculture with economic scale, then, through the use of automated net cage aquaculture technology in the offshore area, the expense of labor cost can be greatly reduced, and the competitiveness of net cage aquaculture can be enhanced. In addition, when burglarproof and security need is put into account, it is needed to add sonar and surveillance system at the peripheral of the net cage in order to prevent human destruction or theft. In addition, since the sea water around Taiwan has longer period of higher water temperature, which facilitates the growth of fish swarm, moreover, slightly stronger ocean flow can prevent the occurrence of red tide and the aging of aquaculture field. The ocean net cage aquaculture in Taiwan has good development in recent years, if the typhoon issue can be surmounted, there will be a quite large space for the development of net cage aquaculture.  Currently, the major fish varieties being cultured in culture in Taiwan include cobia, creator yellow tail, giant grouper, orange-spotted grouper, red seabream and red snapper, etc.  The main purpose of the automation of net cage aquaculture is to promote net cage with large production quantity. Besides, mass net cage aquaculture is going to create mass environmental information.  In order to make the information in the net cage area easier to be controlled by the monitoring personnel, an optimization system based on the integration of net cage aquaculture sensing network and wireless communication can be set up so that net cage aquaculture can easily head towards the direction of large area and mass net cage.  In other words, it is hoped that net cage aquaculture can be promoted in the same way that energysaving and carbon reduction as well as higher economic efficiency is being promoted. In addition, in order to achieve the promotion of automated net cage aquaculture effectively, it is needed to integrate automated underwater technology to provide further support. 
 
AUTOMATED NET CAGE AQUACULTURE FOR ENERGY SAVING AND CARBON REDUCTION
 
Automated operation has an energy saving and carbon reduction effect, and such effect can be seen in agriculture. Take USA as an example. It is well known that its automation is quite high in agriculture, hence, its agricultural product has high value, and the cost is quite low, too. Contrarily, for Taiwan, due to limited land resource, the promotion of its automation is quite slow, and the manufacturing cost is high. However, one solution for Taiwan is the planting of high economic crops, and another way of enhancing its effectiveness is through the enhancement of agricultural land integration and automation.  Moreover, the automation in aquaculture has the effect of reducing the cost of aquatic products, since Taiwan is surrounded by seas in its four sides. The available ocean area is large, and automated net cage aquaculture is believed to be an effective way, not only in terms of larger labor cost in net cage aquaculture, (which is based mainly on labor), but the economic effectiveness of energy saving and carbon reduction can be achieved too. 
 
In the automation of ocean net cage aquaculture, certain important key technologies are needed. For example, underwater technology, net cage technology, automated software and hardware system and sensing system, communication system and information processing system. For net cage technology, it is quite mature today, and of course in Taiwan, due to the increasing number of stronger Typhoons, it is needed to develop floating and submerging system. In addition, individual technologies such as underwater technology, sensing system, communication system, information processing system and automated software and hardware system are all quite mature today. The key is how to integrate all the individual systems into one smart system so as to be applied to the automation of net cage aquaculture and to fulfill the goal of energy saving and carbon reduction. For this part, the research results performed by the underwater technical research team in National Taiwan Ocean University in recent years will be used for the explanation.
 
The underwater research team of National Taiwan Ocean University has more than one decade of research experiences in the underwater technology related fields, which include home-made motor controlled robot arm, the R&D of automated underwater operation system using sensing systems such as underwater camera, ultrasonic range finder and motion sensor. From the construction of two-axis robot arm to five-axis robot arm (Fig. 5), we have finished semi-autonomous controlled underwater robot arm system and have performed salvaging test. Later on, the six-axis robot arm is installed in the six-axis motion simulator (Fig. 6) to simulate the real underwater operation environment with robot arm installed in ROV for carrying out underwater operation, Fig. 7 shows the system architecture diagram of remote control underwater manipulator.  The setup of workflow of object grasping in the water and underwater salvaging have been finished. In the meantime, the underwater robot arm is added with sensing system, and an ultrasonic image sensing system capable of synchronous actions of positioning and image recognition has been developed, which can be adapted to all kinds of underwater environments (including turbid environment). Together with computer and control software, the control of underwater operation device can be made easier, and the measurement accuracy can be made higher. Such technology can be used in the improvement of ROV. Currently, ROV used by our research team is the product of VideoRay, which is shown in Fig. 8. Moreover, our technology team has  also set up the net cage aquaculture system, and has carried out the application of optimization technology in the automation of environmental monitoring system for net cage aquaculture.
 
The job of automated aquaculture environmental monitoring system for net cage aquaculture needs to do sensing and monitoring on net cage aquaculture environment and send back the net cage information in real time basis. The environmental monitoring operation devices for net cage aquaculture include water temperature sensing, water flow sensing, oxidation and reduction potential sensing, cable tension sensing, burglarproof device, photography taking and wireless communication technology, etc. The development of sensing system, burglarproof system, image system and wireless communication system will make it possible to control the factors of the environment of net cage aquaculture in real time. In the meantime, the security and automation of net cage aquaculture can also be enhanced. In order to reduce the effect of typhoon, professor Po-Tai Chen of the Department of System Engineering of National Taiwan Ocean University has simulated the floating and submerging system, which is shown in Fig. 9, in the communication system aspect, the research team of National Ocean University has cooperated with the research of wave power generation in Industrial Technology Research Institute (ITRI) to develop WiFi, 3G and satellite communication technology. Fig. 10 is an illustration of a communication system. It is hoped that net cage automated control system, environmental monitoring system, acoustic burglarproof system and wireless communication transmitting and receiving system can be integrated in our research.
 
Here the net cage automated control includes the ascending and descending mechanism and automated mechanism of floating and submerging. The wireless communication transmitting and receiving system includes the communication transmission technology between net cage secondary station and net cage primary station. The high power wireless transmission technology on the other hand, is between net cage primary station and on-shore monitoring center.  In other words, the development of net cage aquaculture automation has been finished. Our research team has performed initial test too. Fig. 11 illustrates the architectural diagram of the net cage system, and Fig. 12 is an illustration of the sensor deployment, wherein the sensor can be adjusted according to the actual need. In order to simulate the underwater monitoring situation of net cage, we have used again simulated net cage to perform the sensor deployment test. Fig. 13 is sensor and net cage simulation. Fig. 14 is the actual setup situation of a simulation system that simulates the real net cage, and Fig. 15 is the real underwater test diagram showing the placement of five sets of simulation net cages into the yacht dock beside the National Taiwan Ocean University. Fig. 16 is the real-time displayed data from the real acquired signals. Fig. 17 is an illustration of one net cage aquaculture site, wherein the net cage includes monitoring and communication system. With the assistance of working ship and ROV, net cage check can be performed. The automatic bait-feeding system technology not only saves the labor and the working time of the work ship but also allows large scale net cage aquaculture. Through the automation mechanism, energy consumption can be greatly saved, and the energy saving and carbon reduction goal can be achieved. Currently, for marine net cage aquaculture, the aquaculture of Norwegian salmon, can supply half of the global salmon demand. For AKVA group, itis clear that the net cage monitoring system is gradually automated, and the automated system is assured to be feasible to be applied in the marine net cage aquaculture. Because of stronger typhoons in Taiwan, it is needed to develop typhoon-proof system. Although the cost will be increased, yet the automated floating and submerging system cannot only prevent the damage caused by typhoon but also can have higher resistance to temperature change during the winter season. This is an advantage that cannot be achieved in land-based aquaculture. Since Taiwan is surrounded by seas, its ship monitoring technology is quite advanced. If the country or a united corporation can be in charge of the ship team and automated technology then a united ocean, underwater engineering and aquaculture service ship team can be integrated and set up, and a production and distribution resume system can be built up. The fishermen can have an easy way to join the net cage aquaculture system. It is hoped that the government can integrate and plan the setup of aquaculture ocean field and then have the field leased to the fishermen for their operation, and the fishermen can only be in charge of the general net cage aquaculture operation. By doing so, the entrance barrier of net cage aquaculture will be reduced a lot, and all the fishermen can have reasonable profit. Massive development can be expected in net cage aquaculture. With the current advanced aquaculture technology in Taiwan, it is very likely that the production value of Taiwan’s net cage aquaculture can be raised quickly, and the traditional way of aquaculture can be replaced. In the meantime, the acquisition of aquatic product can be expanded to meet the gradually increasing demand on such products. Moreover, the production cost on the aquatic product can be greatly reduced, and the goal of energy saving and carbon reduction can be achieved as well.
 
CONCLUSION
 
If future fishery development can be extended to ocean net cage aquaculture, then with the assistance of automation technology, advantages such as the enhancement of production value, the reduction of production cost and the goal of energy saving and carbon reduction can be achieved easily. Moreover, if the aquaculture area can be effectively expanded, the area of the land-based aquaculture can be gradually reduced, and such land could be returned to agricultural purposes. The increased agricultural land can help to reduce the development of land in the hillside.  Eventually, those lands in the hillside that are not suitable for colonization can be used for tree planting. By returning to the natural state and reducing the loading to the hillside, disaster such as mud flow can be reduced. The reduction of destruction to the earth’s environment is a way to save energy and also increase carbon reduction. 
 
REFERENCES
 
  • Source: World Economic Outlook, International Monetary Fund, April 2008, p. 236.
  • JING-SIAN,LI, PHYSICIAN PHARMACIST PEOPLE, Vol.115, 2010.
  • Source: NEWTON Science Magazine, Vol. 129, 1994.
  • Source: Observing the earth, ESA, 2013-02-08.
  • Source: European Space Agency (2009, September 22). Ozone Layer   Depletion Leveling  Off, Satellite Data Show. ScienceDaily. Retrieved October 12, 2013.
  • Source: Environmental Protection Adminis-tration Executive Yuan, 2012.
  • Source: FAO Fishery and Aquaculture Statistics, 2010. 
  • Source: Offshore aquaculture, FAO Fishery and Aquaculture Statistics, 2010.
  • Source: Council of Agriculture Exective Yuan, 2012.
  • Source: Underwater Technology Research Group, NTOU.
  • Source:Report of the National Science Council, 2002.
  • Source:Chou-Wei Chiu, A Study of Environmental Monitoring System for    Net Cage Culture, master thesis, 2009
  • Source: AKVA Group, 2012.
Fig.1. Global harvest of aquatic organisms in million tons
Source:  reported by the FAO , 1950–2010
                                                                    
 
 
 
Fig. 2.  Fishery and aquaculture statistics 
Source: FAO Fishery and Aquaculture Statistics, ISSN 2070 6057
 
                                                           
 
 
 
Fig. 3.  Main aquaculture countries, 1950–2010
Source: The State of World Fisheries and Aquaculture, FAO 
                                                             
 
 
 
 
Fig. 4. The comparison of Taiwan freshwater output value with its methods in the past two decades
                                  Source: C00000ncil of Agriculture Exective Yuan, Taiwan
 
 
 
 
Fig. 5.  Smart robot arm of the five-axis
 
 
 
Fig. 6.  Smart robot arm of six-axis.
 
 
 
Fig. 7. System architecture diagram of remote control underwater manipulator.
 
 
 
 
Fig. 8. ROV picture.
 
 
Fig. 9.  Overall structure of net cage floating and submerging control system
Source: Prof. Po-Tai Chen
 
 
Fig. 10.   Illustration of the communication of net cage aquaculture group organization
 
 
 
 
 
Fig. 11.   Architectural diagram showing the application of optimization technology in the automation of the environment monitoring of net cage aquaculture 
 
 
 
 
Fig. 12.   The sensor deployment of simulation net cages
 
 
 
Fig. 13.  Environmental monitoring system architecture of net cage.
 
 
 
 
Fig. 14.   The simulation system that simulates the real net cage.
 
 
 
Fig. 15.  The real underwater test diagram showing the placement of five sets of simulation net cages into the yacht dock beside National Taiwan Ocean University.
 
 
Fig. 16.  The real-time displayed data from the real acquired signals.
 
 
 
Fig. 17.   Illustration of one net cage aquaculture site.
 
 
 


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