United States Shellfish Delegation to Japan

November, 2000

In November of 2000, Dr. James McVey, NOAA Sea Grant, organized and supported a Shellfish Delegation to meet with Japanese scientists, managers and industry in close coordination with the United States Japan Cooperative Program in Natural Resources (UJNR).  Dorothy Leonard of NOAA Fisheries served as group leader.  The schedule was planned to coincide with the UJNR meeting, which was held in Ise and Ishigaki (Okinawa Prefecture). The delegation departed the US on November 2, returning November 12 and 13.

 

Picture of delegation members.

Delegation Members from U.S.A.

1st row, left to right: Mr. Frederick Kern; Dr. Daniel P Cheney; Ms. Dorothy L. Leonard, Delegation Chair; Mr. Bill Dewey; Dr. Ralph A. Elston  2nd row,  left to right: Dr. John Supan; Ms. Lori A. Howell; Mr. Ken B. Moore; Dr. Carolyn S. Friedman


Report of the Delegation:

Dr. Makoto Yamasaki Golden Paviilion, Kinkaku - ji Photo of Classical teahouse

On November 3 all US Shellfish Delegation members arrive in Kansai Airport and were met by Dr. Makoto Yamasaki to assist in our travel to Kyòto and our subsequent tour of Kyòto’s finest temples on Saturday, November 4.   We began our tour at the Ginkaku Temple established in 1482, the best place to observe both the Higashiyama and Zen cultures.  Within are Kan'nonden, considered a National Treasure and the Buddhist Hall which is the oldest existing Shoin style building in existence.   We visited Kinkaku Temple, the Golden Pavilion, and a classical teahouse, Sekkatei at the  Rokuon temple, construction of which began in the 1220s. We also visited the Ryoanji Temple where the rock garden, a rectangular Zen garden, laid out at the end of the 15th century, is the outstanding feature. Only 15 rocks and white gravel are used but its simple beauty captures the imagination and inspires philosophical meditation.  The major challenge to the Americans traveling in Japan was the crowds.  Protective of our personal space we had difficulty managing the packed buses and streetcars.  On the other hand the trains are very comfortable as your seats are assigned.  The Japanese transportation system is efficient and clean and enables travel throughout Japan at a very reasonable cost.

On Sunday, November 5, the group left Kyòto for Hiroshima under the guidance of our Japanese hosts, Dr. Tomoyoshi Yoshinaga and Dr. Kazufumi Takayanagi.  The visitors from the United States had requested the tour of Hiroshima as the most important shrine that we would visit during our tour.  We toured the Hiroshima Peace Memorial Museum and Park extensively, from which we could view the A-Bomb Dome .  We had the opportunity to visit the Hiroshima Museum of Art and the beautifully restored Shukkei-en,  the name means “shrink-scenery garden”.  In the center of Shukkei-en is Takuei Pond containing more than 10 islets and encircled by mountains, valleys, bridges, tea cottages and arbors.

Peace Memorial Museum burial mound. Memorial arch Peace Memorial Museum Entrance

On the evening of November 5 we were treated to a traditional Hiroshima cuisine hosted by Dr. Kunihiko Fukusho, Director General of the National Research Institute of Fisheries and Environment of the Inland Sea.  The US Delegation presented Dr. Fukusho with a gimbaled clock engraved for the occasion and all of the Japanese scientists received US/Japan oyster pins specifically designed for the delegation.

National Research Institute of Fisheries & Environment of Inland Sea National Research Institute of Fisheries and Environment vessel FEIS Scientists with Dr. Supan

The morning UJNR seminar included talks by several of the scientists at FEIS beginning with Dr. Uchida who presented an overview of the red tide occurrences and effects of Heterocapsa circularisquamaH circularisquama occurred first in the Inland Sea in 1988 and by 1995 had spread so widely that it caused extensive mortalities (approximately 355 MT) to clams.  It is toxic to shellfish but not to finfish.  In the case of clams and oysters mortalities occur within 24 hours.  H. circularisquama forms temporary cysts that respond to temperature and salinity (ideally >30c and >25 ppt)and other planktonic species and utilizes compounds such as nitrogen and phosphorus and glycerin.  Dr. Nagasaki presented research on the use of viruses for red tide elimination.  The virus, HaV (several species) isolated from seaweed will disrupt the organelles of the dinoflagellates within 48 hours. Dr. Akashige gave an overview of the shellfish industry and of oyster culture at Hiroshima. In his overview he said that over 80 percent of oyster production is from 2 areas; Miyagi and Okayama.  In the winter, oyster rafts, which were introduced as a culture method in the mid 1950s, are moved from upper Hiroshima Bay to offshore.  In 1970 there were more than 10,000 rafts with production at 30,000 tons.  From 1990-2000 there has been a decrease to 16,000 tons, the decline attributed to weather, overcrowding, red tide and toxic poisoning.  In the Inland Sea, oysters spawn from late June to September.  However, recent emphasis has been on the production of triploids (approximately 100 million in 2000) with a related increase in meat weight.

The shellfish delegation gave two papers; one by Bill Dewey discussing water quality and habitat issues of the US West Coast industry and John Supan presenting the research issues of the Gulf Coasts oyster industry. Lunch was a Japanese style lunch box beautifully presented by our hosts. 

Unopened Japanese box lunch Display of lunch food Japanese field trip vessel SETO Photo of raft culture
Oyster processing plant Processing oysters Scallop shells for collection of oyster spat Hiroshima Train Station seafood display

 In the afternoon Dr. Takayanagi and Dr. Usuki took us in the research vessel, “SETO” to the area where oysters are being cultured.   (The “on-water” trip was followed by a visit to an oyster processing plant. The evening was highlighted by a dinner party at “Ginza Lion” at Hiroshima Train Station where we also shopped the myriad of seafood products available.

On November 7 we left for Ise City to join the UJNR seminar in progress. On November 8, Drs. Fred Kern, Ralph Elston and Carolyn Friedman were among the scientists presenting papers on pathogenic organisms and disease prevention

On November 9, we were able to get out in the field to observe shellfishing activity. We traveled by bus to Hazamura to visit the Fisheries Co-operative Association and by boat to observe the Density Current Generating System owned by the Cooperative and described by Dr. Kazuyuki Ouchi of Ouchi Ocean Consultant, Inc. The density current generator simultaneously takes in less dense water from the surface and denser water from the bottom.  It mixes the water with an impeller, and pumps it out horizontally into the middle layer.  This intermediate-density mixed water creates a density current, which diffuses horizontally over a long distance.  Density current refers to the phenomenon of a liquid of a given density flowing into a liquid stratified with different densities will flow into a layer of the same density.  The impeller is driven by an electric motor powered by a solar cell with a maximum output of 12kw.  The volume of mixed water discharged from the generator reaches a maximum of about 170,000m3/day (120m3/minute).  At night, when the solar cell cannot produce electricity, a land-based power source takes over, ensuring a minimum volume of 120,000m3/day.  The impeller is an environmentally friendly system that makes optimum use of the renewable energies of gravity and sunlight, and incurs minimal operating costs.  Since June 1997, a demonstration density current generator has been in operation in Gokasho Bay in Mie Prefecture, Japan.  The generator, placed 15m deep, produces a density current in Gokasho Bay, which flows steadily across a wide area.  Temperature stratification has weakened, and water transparency has improved.  The red tide that normally appears at one end of the bay in summer season did not appear, and oxygen consumption at the sea bottom was greatly reduced.  Anecdotally, local residents report more fishes in the bay.  

Shellfish farm Hazamura, Japan sculpture of fish Density Current Generating System
Density current generator impeller. Solar panels for density generator. View of fisherman's cooperative

We then visited the National Research Institute of Aquaculture (NRIA) in Nansei where we met with Dr. Makoto Yamasaki, Chief of the Research, Planning and Coordination Section, Dr. Takashi Kamaishi of the Pathology Division and Drs. Takayanagi, Yokoyama, Inoue, Nakajima and Director General Dr. Yasuaki Nakamura. The discussion covered many areas of aquaculture including pathology and environmental issues. Nansei Station faces Gokasho Bay, which we viewed during our lunch at the facility.  The Environmental Management Division focuses on hydrodynamics and the matter cycle mechanism in mariculture farms, the relationships between organisms and physico-chemical factors of their environment to provide the information necessary to manage the water quality and benthic habitat of the farms, and the environmental evaluation system based on the eco-physiological responses of organisms to environmental stimuli. The Fish Pathology Division is conducting studies to elucidate the physiology and ecology of viruses, bacteria and parasites to establish preventative measures.  They are also conducting basic studies on the malignant physiology and immunology of aquatic organisms and to develop health management techniques such as vaccination.  The scientists at NRIA are investigating the metabolism of drugs with utility to treat disease with the objective of preventing diseases of aquatic cultured organisms.

Staff at the National Research Institute of Aquaculture in Nansei Gokasho  Wan, from Nansei Station Raft culture scene

On November 10 we left Ise City for the Matoya Bay Research Laboratory, guided by Dr. Tetsuo Seki, Director of the Genetics Section of NRIA and Dr. Yamasaki. The Matoya Bay Oyster research Laboratory, directed by Hideo Tahara, was established in 1930 to track the effect of changes in Matoya Bay on primary productivity and the rearing of Crassostrea gigas and Pinctada fucata martensii, the pearl oyster.  Although production of the pearl oyster has declined, the C. gigas continues at relatively high production levels in spite of decreasing levels of plankton.  These decreases are explained by the cultivation of green laver and a short term, but devastating growth in the cultivation of pearl oysters.  It was through the Matoya Laboratory that Sato Oyster Culture Company developed a purification system for their oysters.  The company, headed by President Fumio Sato, produces oysters of exceptional quality in an ecosystem that can be very productive and yet affected by red tides, stratification and pollution.  These Matoya oysters are prized for live sales and raw half shell consumption.  It is necessary that the oysters be depurated.  The firm has been depurating oysters since 1954.  The Matoya firm depurates oysters for 12 to 24 hours, significantly shorter than the 44 hour depuration time required in the United States.    Also of interest in this facility was a continuous flow oyster shucked meat washer.  In the United States companies use predominantly single batch washers, which are relatively inefficient compared to this continuous washer.  Details regarding the make and cost of the machine were provided following the trip. Oysters were cultured in similar fashion to Hiroshima Bay.  Clusters of oysters were produced on hanging longlines from natural set seed on scallop shells with spacers between.  At maturity the clusters were harvested, broken into singles and returned to the bay in lantern nets for a period of healing and hardening prior to sale. The Matoya firm also has a line of the most beautifully colored scallops ever seen.  They ranged from brilliant yellow to stunning orange to vibrant pinks and purples.  These scallops are selected for their colors.  They are sold by the firm in boxes containing several oysters of each color making a beautiful presentation.  A few of us were able to sample the raw scallops there on the culture raft- and they tasted as good as they looked.

Closeup view of scallops Orange, yellow and purple scallops in net Opened scallop shell with meat

On November 10 we left Ise City for the Matoya Bay Research Laboratory , guided by Dr. Tetsuo Seki, Director of the Genetics Section of NRIA and Dr. Yamasaki. The Matoya Bay Oyster research Laboratory, directed by Hideo Tahara, was established in 1930 to track the effect of changes in Matoya Bay on primary productivity and the rearing of Crassostrea gigas and Pinctada fucata martensii, the pearl oyster. Although production of the pearl oyster has declined, the C. gigas continues at relatively high production levels in spite of decreasing levels of plankton.  These decreases are explained by the cultivation of green laver and a short term, but devastating growth in the cultivation of pearl oysters.  It was through the Matoya Laboratory that Sato Oyster Culture Company developed a purification system for their oysters. The company, headed by President, Fumio Sato, produces oysters of exceptional quality in an ecosystem that can be very productive and yet affected by red tides and stratification.

Sculpture at Matoya Bay Research Lab Oyster probably
	C. gigas Purification system for pearl oysters Pearl oysters in  baskets

November 11 was our last day for technical and sightseeing tours as a group and we began with a trip to Toba Pearl Island.  The first pearl culture in the world was developed here by Kokichi Mikimoto in 1893 and is currently cultured in rafts in this quiet inlet.  The Ama, women divers, dive into the sea for the cultured pearls and, although other methods are now employed, we were able to watch Amas dive at Mikimoto Pearl Island.  From the very beginning these Ama worked along side Kokichi Mikimoto placing mother oysters deep on the ocean floor and bringing them back up.  It was difficult to divert us from the Pearl Museum where the process of a pearl from creation to production is introduced including a demonstration of each of the steps.  The pearl is composed of thousands of layers of calcium carbonate crystals and a hard protein called “conchiolin”.  The pearl color results from light effect, pigments contained in conchiolin and organic matter.

Following our trip to Pearl island we visited Ise Jin-gü, principally composed of the Kōtaijingū (Naikū) and the Toyoukedaijingū (Gekū) where the supreme deity AmaterasuŌmikami and the great deity Tokouke Ōmikami are worshipped. The Hiyoke Bridge is the entrance to Gekū while the Uji Bridge is the entrance into Naikū.  Since ancient times the Japanese people have lived in accordance with nature.  All over Japan there are consecrated rocks and evergreen trees in which kami (powerful beings) reside as well as sanctuaries (generally called jinja) in which kami are enshrined and which usually consists of a building surrounded by a grove of trees.  According Shintō, the indigenous religion of Japan, kami are worshipped in matsuri, which include solemn ceremonial occasions as well as festivals.  There are more than 100,000 Shintō sanctuaries in Japan which are at the center of spiritual life.  We were honored to observe some of the ceremony and a wedding party within the sanctuary. 

Plaque stating first culture pearl was born on July  11, 1893. Ama women divers in Japan Pearl screening device  
Mikimoto Pearl worth 1,500.000 YEN Naiku entrance Shinto shrine  

Our Japanese hosts were generous and thoughtful, balancing our thirst for shellfish-related information and our desire to learn more of the culture.  Although our time in Japan was short our knowledge was greatly enhanced and we made some friendships that will help to achieve the goals of the UJNR: promote conservation of marine and terrestrial resources through cooperation in applied science and technology.  We learned of the Japan Science and Technology Agency (STA) and the opportunity to send some of our young shellfish scientists to Japan to conduct research at the facilities we visited. Through the bonds of friendship and three decades of scientific collaboration, the United States and Japan have made significant progress in understanding natural processes and promoting sound management of our precious natural resources. 

Some of the delegation members have been in communication with our Japanese hosts to gain additional information and discuss possible collaborations.  In response to questions posed by our US industry regarding the High Hydrostatic Pressure processing equipment being developed in Japan. The system patented in Japan uses a process that puts the product through 40 degrees centigrade heat process for 15 minutes and then submits the batch to pressure of 11,379 psi for five minutes.  The cycle of 150 oysters takes 5 minutes.  The cost of the equipment is 70,000,000 yen or ~$700,000.

High Hydrostatic Pressure equipment Automatic oyster meat washer. Matoya Oyster Company oyster meat washer

The automated shucked oyster meat washer demonstrated at Matoya Oyster company is model JAW-1835B. It contains 300 liters of water at a flow of 800-1500 liters per hour.  The price in Japan is 1,000,000 yen or ~ $10,000.  Bill Dewey also communicated with Dr. Kazufumi Takayanagi (Kazu) regarding Japan's petition to WHO to change the Vibrio parahaemolyticus action level to 100 MPN (total vibrio) to see if he was aware of any science the country had to support this petition.

We expect to continue and expand those activities by increased collaboration with our shellfish colleagues in Japan in the following areas of research: Pacific oyster summer mortality and triploidy, augmentive bio (virus) control of harmful algal blooms, carrying capacity for shellfish culture and vibrio parahaemolyticus.

Submitted by Ms. Dorothy L. Leonard with photos by Dr. John Supan



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