News Letter Vol.6
Kinki University 21st Century COE Program English Site > News Letter Vol.6
Progress of the cross-group project

Shigeru Miyashita (Cross-project member)

At this research site, we launched two projects for systematically coordinating the research groups in fiscal 2004. One is for the development of a bluefin tuna culture manual. The culture technology for this species has been established through trial and error and through experience since the facilities are large and comparative experiments are difficult to do, and few reports are available on this. And because formula feed which meets the nutritional demand of this species has not been developed yet, living feed is used in the main, resulting in low feeding workability and difficulty in steady flesh control. Since 2000, the sharp increase in the imports of cultured tuna has pushed down the market price. These are the major challenges for today's bluefin tuna culture that should be resolved immediately as cost reduction is an imperative. Thus, this project tries to make a comprehensive evaluation of the impact of feed efficiency, growth, flesh quality, and market evaluations upon the effects of culture through the systematic coordination of the four groups, that is, Seedling Production and Culture, Environment and Behavior, Feed, Nutrition and Flesh Quality, and Economics and Distribution, and commercialize formula feed. This experiment requires the university's support as the facilities are large and test fish are expensive.

Another project relates to the development of environmentally friendly production technology and was launched in response to public concern about the safety of food, a challenge that should be solved for the culture industry to grow. This projects aims to develop initial breeding technology for bluefin tuna and red sea bream which eliminates the need for drugs through the activation of immune function. At the same time, since this research requires a microbial environment approach, it also covers the development of initial feed for small larval-type fishes whose seedling is difficult to produce as they cannot eat rotifer. Useful small larval-type fishes include grey large-eye bream and blubberlip snapper, which are very expensive in Japan and Southeast Asia, respectively. Grey large-eye bream spawns once a year in early summer, while blubberlip snapper spawns all year round in Borneo. Thus, joint research with the University Malaysia Sabah Borneo Marine Research Institute, which has an overseas academic agreement with Fisheries Laboratory, will make it possible to conduct more experiments and give our graduate students and young researchers opportunities to exchange academic opinions with foreign researchers, contributing to human resource development contemplated by this site. In fiscal 2005, personnel from the Seedling Production and Culture Group and the Environment Group visited University Malaysia Sabah for joint research. The report from the Environment Group was published in Volume 4 of this Newspaper, and this volume contains a research activity report by members of the Seedling Production Group.

(1) Project for the development of a bluefin tuna culture manual

Shigeru Miyashita (Seedling Production and Culture Group, Fisheries Laboratory)

This research is conducted at the Oshima test site located in Kushimoto, Wakayama Prefecture and the Amami test site located in Setouchi, Kagoshima Prefecture. Large and small preserves were created in June 2004 to initiate experiments. However, all the test fish in Amami were killed by typhoon No. 18, which hit the test site in September, three months after the launch, so the experiment was resumed in fiscal 2005.

Details in fiscal year 2005

Floating-type tuna preserve at the Amami test site
(Front: large preserve, right rear: small preserve)
This year, we started on June 25, keeping 1,300 fish in the large preserve and 50 in each of the small preserves (average weight of approximately 13kg). In order to make a comparison with waters with a different environment, we kept 337 in a 30m-diameter preserve in Kushimoto (average weight of approximately 14kg). This experiment is designed to investigate the impact of the environment of fisheries upon fish growth and flesh quality and assess the impact of the frequency of feeding (once and twice a day, respectively) upon the effects of culture using the two small preserves in Amami, and elucidate the impact of the size of a preserve upon growth, flesh quality, etc., through comparison with the large preserve, on the basis of the analysis of the physical environment and swimming behavior obtained from data loggers implanted in the abdominal cavity of the test fish.

This year, neither Kushimoto nor Amami has been hit by typhoons and the fish in the large preserve are growing steadily. However, severe depletion has occurred in the small preserves in Amami, possibly due to collisions caused by a series of thunders in July, soon after the start of the experiment, and there is concern that the intended results may not be obtained (as of the end of January, there are 12 and 17 survivors, respectively). The experiment will be continued until the coming spring, by which time the test fish will have grown to the ordinary shipment size. Then we will analyze the effects of culture including market evaluations. We have already obtained valuable data from behavioral analysis and the Environment and Behavior Group, which is in charge of this experiment, will be the first to announce the results.

(2) Project for the development of environmentally friendly production technology — Academic exchange with University Malaysia Sabah —

Yoshizumi Nakagawa, COE doctoral researcher (Seedling Production and Culture Group, Fisheries Laboratory)

I stayed at the University Malaysia Sabah Borneo Marine Research Institute (hatchery) for 48 days from December 13, 2005 to January 29, 2006 and conducted an experiment under the supervision of Professor Shigeharu Seo, for the purposes of the 'Examination of initial feed and the development of seedling production technology for the fish which is highly difficult to breed (small-larval type)', which forms a part of the cross-group project 'Development of environmentally friendly production technology'. The experiment was designed to elucidate the feed intake ecology of blubberlip snapper (Lutjannus rivulatus, locally called hoi-tai-kai) at the early larval stage, which is an expensive species in Southeast Asia and for which breeding technology has not been established yet. We focused especially on the understanding of food intake ecology at the start of food intake. I would like to refrain from mentioning the climate and culture of Kota Kinabulu, Malaysia, the work and life at the hatchery, and the status of local seedling production, as these topics were already reported in detail by Mr. Gentoku Nakase, a graduate school doctoral course student (Environmental Conservation and Source Dynamism Group, Graduate School of Agriculture) (see his report on a short stay at University Malaysia Sabah in Newsletter Vol. 4).

Ching Fui Fui, a research assistant and graduate school student (master) took care of me in all aspects of my experiment and life during the stay. The theme for Fui Fui's master thesis is to breed blubberlip snapper with a variety of feed to increase survivors. We conducted the experiment together at all times.

Why is larval blubberlip snapper difficult to breed?
Blubberlip snapper belongs to Lutjanidae and is distributed in waters in the tropical and subtropical zones. The ovum is around 0.8mm in diameter and the larval is around 2mm long, smaller than larval red sea bream. One of the reasons why larval blubberlip snapper is difficult to breed is (1) it has a small mouth. Larval blubberlip snapper cannot take in rotifer, which is generally used as initial feed. Also, larval fish at the early larval stage cannot eat feed until the mouth is formed, the lower jaw moves, the eyes blacken and move, the intestines and the anus open and move peristaltically, and sensory organs such as free neuromasts are formed. In this period, the yolk sack is used as energy for growth. Larval fish cannot survive unless they take in some feed before the yolk sack has been absorbed. The yolk sack of larval blubberlip snapper is small and absorbed in a very short time. Therefore, (2) switchover from internal to external nutrition should take place in a very short time. This is another factor that makes it difficult to breed larval blubberlip snapper. Professor Shigeharu Seo refers to this period of changeover from internal to external nutritional source as the 'Nutritional changeover period'. According to Professor Seo's thesis, the longer the nutritional changeover period is, the easier the breeding is, while the shorter the nutritional changeover period is, the more difficult the breeding is. To mention an example of University Malaysia Sabah, what makes it difficult to breed larval grouper is a short nutritional changeover period. In the meantime, a graduation thesis was presented at a seminar, reporting that African catfish (Clarias gariepinus) has a nutritional changeover period of about one week and 100% of the larvae survive if they are fed, for the first time, five days after hatch.

Experiment at University Malaysia Sabah
Observing the contents of the intestines of larval blubberlip snapper
Together with Fui Fui, RA.
To support Fui Fui's master thesis, we conducted a survival experiment on larval blubberlip snapper together. We used emulsified cod-liver oil (COJ), the stirred yolk of an boiled egg (BE), and the yolk of a raw chicken egg (RE) as feed, and gave them separately to three independent sections, provided both BE and COJ to another section (BE+COJ), and supplied both RE and BE to yet another section (RE+COJ) to conduct a survival experiment until the test fish become ten days old. As was shown by the experiments conducted previously by Fui Fui, only the test fish in the BE section survived to be ten days old (the survival rate was 11.2%). The larval blubberlip snapper in the BE+COJ section survived to be nine days old, while breeding in the other sections was brought to an end when the fish became seven days old. In order to confirm first feeding before the yolk sack is absorbed, we checked the blackening of the eyes, the sensory organs, the movement of the lower jaw and the intestines as well as the contents of the intestines. At the start of feeding, Nannochloropsis accumulated in the intestines. We are not sure if the larvae took in Nannochloropsis as feed, but this observation is of great interest to us. In the BE+COJ section, we simultaneously investigated the composition of the environmental water and of the contents of the intestines, determining selectivity using the selectivity index α of Chesson (1978). We found that BE was selectively took in at all the ages researched. The observation of the contents of the intestines showed that BE needs 30 to 45 minutes to pass through the intestines while COJ goes through the intestines within 60 minutes. It still remains as a task to check whether BE is digested and absorbed, but when we observed the breeding water under a microscope, Protozoa (mastigophoran less than 3µm long and ciliate around 10µm long) gathered on the surface of BE and the surface of BE was found to be melt. Larval blubberlip snapper may be surviving on these microbes and amorphous substance. These results will contribute greatly to initial feed formulation for the development of breeding technology for larval blubberlip snapper. However, I don't think that these feeds fully meet the nutritional demand of larvae. My opinion is that natural plankton is the best feed. Thus, simultaneously with the above-mentioned experiment, we collected natural plankton at a pier at a distance from the hatchery and conducted a food intake experiment at the start of feeding (which is assumed to take place one or two days after hatch), using plankton 40µm to 100µm long as feed. We are now analyzing the samples.

At the same time, Nguang Siew Ing, also a graduate student, observed the development of each organ of larval blubberlip snapper, the yolk sack disappearance process, and the feeding status. The movement of the eyes, the intestines and the lower jaw and the formation of free neuromasts were confirmed and the larvae became able to feed in 42 hours after fertilization (one day after hatch). And the yolk sack disappeared in 60 hours after fertilization and it was found that the nutritional changeover period is as short as 18 hours (at the water temperature of 29 degrees centigrade). COJ and BE around 10µm long were found in the intestines of one-day-old larvae.

Life at the laboratory and the hatchery
Students, RA, Professor Shigeharu Seo (first right), and the reporter (second right) waiting for the first sunrise of 2006 at the university
During my stay, many university students visited the hatchery every day for training or to write their graduation theses. Professor Shigeharu Seo said at the meetings held three times a day, 'Safety work!', 'Happy work!', 'Don't kill fish!' and that we should be prudent when working and be willing to greet and that it is good, but minimum, manners to clean the toilet after use. By the time I returned to Japan, people had begun to greet one another frequently, and I could concentrate on my work and experiment in a pleasant, peaceful atmosphere which was shared by many people. When blubberlip snapper did not spawn and breeding and feeding experiments could not be done, many graduate students not only discussed the matter with Fui Fui, also sought my advice and comment on their own research results and analysis methods. I gave them all of my knowledge and spent much time on discussion. They ask many questions and exchange opinions vigorously at the laboratory seminar held every Friday. I was also given an opportunity to give a presentation at the seminar. I presented part of the results of this COE project research, receiving many questions after the presentation. I feel it was a very good experience to me. On January 1, 2006, I went to the office earlier than usual and saw the first sunrise of the year on a hill in the university together with Professor Shigeharu Seo, research assistants, and students. I wished on the holly shining Sun for world peace and the safety of my family. This was also an impressive experience.

I would like to apologize Professor Shigeru Miyashita, the staff of the Seedlings Center Shirahama Site, the graduate students, and the students who are now preparing their graduation papers for the trouble caused by my absence from Shirahama. And I would like to express my sincere appreciation to Professor Hidemi Kumai, Leader of Kinki University Fisheries Laboratory, Professor Osamu Murata, Deputy Leader, Professor Saleem Mustafa, Director of the University Malaysia Sabah Borneo Marine Research Institute, Professor Shigeharu Seo, Instructor Yukinori Mukai, Instructor Sitti Raehanah Muhd. Shaleh, the hatchery staff, the graduate students (RA), the students, and all the people I met in Malaysia, for giving me this valuable experience. I'm sure that I will never forget this experience. I will continue my joint studies, hoping to contribute to the further promotion of academic exchange with University Malaysia Sabah.

2005 5th symposium report for the 21st Century COE Program
Sustainable culture production, flesh quality and safety, and distribution of bluefin tuna

Kenji Takii (Symposium committee, Fisheries Laboratory)

Poster presentation
We held a 2005 results report meeting entitled 'Sustainable culture production, flesh quality and safety, and distribution of bluefin tuna' and a poster presentation entitled 'For the future fish culture industry' at November Hall, Small Hall and the second floor lobby of Large Hall of Kinki University on February 24 and 25, 2006. Since the presentation time was limited and the presentations were too technical at the last year's 2003/2004 results report meeting, the presentation time given to each lecturer was extended to 30 minutes and the presentations centered around plain and interesting subjects at this year's meeting. We are happy to hear many participants say that the presentations were easy to understand and were interesting.

On the first day, Vice President Satoshi Munakata delivered an opening speech, followed by Part 1 'Mass production of seedling and cultivation technology', at which the teachers and PDs of the Seedling Production and Culture Group reported new achievements related to maturity and oviposition, initial growth, embryo manipulation and sperm freezing technologies, fat accumulation, surfacing and bottoming death, methods for the prevention of collision death, visual characteristics, feeding/swimming and body temperature change, the nutritional demand of larval fish. We felt that great progress has been made toward the mass production of seedling of bluefin tuna.

Panel discussion
Held on the second day were Part 2 'Environmental conservation and culture facilities', Part 3 'Flesh quality and safety', and Part 4 'Management, distribution, and sale', at which the teachers and PDs of the Environmental Conservation and Source Dynamism Group, the Food Safety, Processing, and Animal Feed Group, and the Economics and Distribution Group gave reports and exchanged opinions with respect to bacterial communities in breeding water, water quality and substance circulation, culture facility design, swimming ability and behavioral pattern, change in quality of refrigerated flesh and improvement methods, the reduction of mercury content, the current status of and problems with production and distribution in and outside of Japan. Since the achievements relate to today's big concerns, that is, sustainable culture production, source increase, food assurance and safety, and distribution and price determination, we received many exciting questions from the participants.

On the second day, we held a panel discussion in Part 5 entitled 'Suggestions to fish culture research'. The panel, including Mr. Eiji Ishigaki (Co-op Kobe), Mr. Akira Ishida (Nippon Formula Feed Manufacturing Co., Ltd.), and Mr. Ryozo Moriwaka (Chikuji Fish Market), advanced interesting opinions and severe suggestions about future culture research, as the representatives of the consumers, the producers, and the distributors, respectively. In particular, we were very happy to discuss with the participants such matters as the branding of produced fish, production history records and assurance and safety, food education, and price optimization. Lastly, COE Leader Hidemi Kumai (Fisheries Laboratory Leader), who took the chair in the discussions, said that, in order to overcome the difficulties facing the fish culture industry and develop and survive for the future, it is very important for the researchers to understand the current situation and work with problem consciousness and the COE will make its best effort to meet the expectations. The 2005 results report symposium ended with success.

I would like to thank the many participants and people concerned for their great support in the administration of this symposium.
A record of my tuna research travel in Southern Europe — The current status of bluefin tuna culture and management in the Mediterranean —

Ken Hidaka (Economics and Distribution Group, Graduate School of Agriculture)

A six-person investigation group, consisting of Professor Seiichiro Ono as the leader and members of the Economics and Distribution Group and Professor Shigeru Miyashita of the Aquaculture Group, conducted a hearing survey on the status of tuna culture and the management of tuna fishing and culture in the Mediterranean, especially in Spain, for 11 days from October 31 to November 10. Presented below is the information collected at the four sites we visited.

1. ICCAT, International Commission for Conservation of Atlantic Tunas
Regulations on tuna fishing and bluefin tuna culture through the breeding of natural fish from the Atlantic to the Mediterranean are imposed by ICCAT. We visited the ICCAT headquarters in Madrid and interviewed the director-general of the secretariat and an official sent from the Japanese Government. The decrease of bluefin tuna sources in the Atlantic and the Mediterranean is considered to have been accelerated by tuna culture, and it is an imperative to manage tuna culture. Thus, ICCAT develops guidelines for sustainable tuna culture in conjunction with GFCM, General Fisheries Commission for the Mediterranean. Tuna culture in the Mediterranean is not placed under rigid control, so regulation will be tightened in the future.

2. IEO, Spanish Institute of Oceanography (Murcia)
At the culture laboratory of IEO, Spanish Institute of Oceanography
(Mr. Antonio Garcia at the center)
There is an EU research project involving Spain as well as France, Germany, Greek, and other Mediterranean countries under which the collection of bluefin tuna ovum through hormonal treatment and a larval fish breeding experiment are being conducted. We visited the IEO culture laboratory in Murcia in the southern part of Spain and interviewed Mr. Antonio Garcia, who is in charge of ovum collection and the breeding experiment, about the progress of the experiment and also exchanged information with him about culture information. The laboratory succeeded in the collection of fertilized ovum from bred natural parent fish in July 2005 and also conducts larval fish breeding experiments. The laboratory seems to be interested very much in the achievements of Kinki University.

3. TFM, a culture company (Murcia)
A bluefin tune culture site in Cartagena Spain
The feed (mackerel) at the lower right is carried by water to the center of the preserve through a pipe. The preserve is round and 90m in diameter.
Spain is the world's largest bluefin tuna cultivator. We visited TFM, a culture company headquartered in Murcia, a major culture site in the southern part of Spain. The technical manager of TFM is Mr. Norida, a former official of Kinki University. We interviewed Mr. Norida about the status of tuna culture and inspected a culture site in Cartagena, guided by him. This company is a culture production company and subsidiary of Antarba, producing around 1,100 tons of 110kg-class cultured bluefin tuna a year. Fish for TFM are collected by round haul netter companies in Italy and France from the end of May to the end of July and are bred on mackerel and sardine. Shipment begins around the middle of November, fresh fish (mainly entrusted to brokers) and refrigerated fish (purchased by brokers) being shipped mainly to Japan by air and sea, respectively.

4. FAO, Food and Agriculture Organization (Rome)
FAO develops tuna fishing and culture guidelines for the conservation of bluefin tuna sources in coordination with ICCAT. We visited Aquaculture Management and Conservation Service of the FAO headquarters to give a presentation of Kinki University's tuna research projects and exchange opinions about tuna fishing and culture. The Director-General of the Service is Mr. Nomura, a former official of the Japan Fisheries Agency, and a few others have been sent from the Agency. We would like to thank receptionist Mr. Watanabe in particular. FAO shares with ICCAT concern about the decreasing tuna sources and considers it necessary to place tuna fishing and culture under appropriate control. Controls and regulations are imposed by ICCAT, while FAO plays an active role in the collection of information and the advancement of administrative suggestions. At the same time, tuna as a rapidly growing source of protein has been of interest to FAO, which said it is necessary for Kinki University to provide its knowledge and technology related to full culture or conduct joint researches. Kinki University was also invited to take an active role in the many meetings held in Europe concerning tuna sources and fishing or culture management. We were impressed with the strong interest shown by FAO as well as IEO in the knowledge and technology related to bluefin tuna culture which have been developed and accumulated by Kinki University. FAO has suggested the necessity and possibility of information exchange, technical partnership, or joint research, so it seems that these international collaborations are highly feasible if Kinki University is prepared for them.