Challenge of restocking in Japan with special reference to larviculture Hiroshi FUSHIMI Fukuyama University, Faculty of Life Science & iotechnology Department of Marine iotechnology Laboratory of Aquaculture & Stock Enhancement Ohama, Innoshima, Hiroshima 722-2101, Japan E-mail: hfushimi@ma.fuma.fukuyama-u.ac.jp
Scope Progress of production of hatchery-raised juveniles and restocking 1. rief history of stock enhancement in Japan 2. Challenge of restocking in Japan with special reference to larviculture I. The System and Roles of Stock Enhancement II. Procedure and technology needed for restocking III. Progress in Production of Hatchery-raised Finfish Juveniles for Stock Enhancement IV. Scale of Hatchery-raised Seed for Stock enhancement in Japan New Challenge for the Resource Restoration Plan in Japan
Progress of production of hatchery-raised juveniles and restocking in Japan
rief History of Stock Enhancement in Japan 1961 The Japan Fisheries Agency established a plan to promote coastal fisheries by stock enhancement. 1962 The Seto Inland Sea was selected as a model littoral zone for stock enhancement. 1963 The Seto Inland Sea Fish Farming Association (SISFA) was established as the base of operation for intended technological development by commission from the government. 1979 SISFA was reorganized and renamed the Japan Sea-Farming Association (JASFA). 2003 JASFA was united to Fisheries Research Agency, and renamed National Center for Stock Enhancement (NCSE). 2006 6 NCSE were united to 4 Regional Fisheries Research Institutes of FRA.
rief History of Stock Enhancement in Japan (2) y the late 1970s The technology of artificial seed production of finfish had been established in Japan. Hatchery-raised seed play an important role in supplying seedlings to aquaculture. Hatchery-raised seed supply most of the demands of aquaculture; Red sea bream Pagrus major, Ocellate puffer Takifugu rubripes, striped jack Pseudocaranx dentex, Japanese flounder Paralichtys olivaceus, and Kuruma prawn Penaeus japonicus
Challenge of restocking in Japan with special reference to larviculture I. The System and Roles of Stock Enhancement II. Procedure and technology needed for restocking III. Progress in Production of Hatchery-raised Finfish Juveniles for Stock Enhancement IV. Scale of Hatchery-raised Seed for Stock enhancement in Japan
I. The System and Roles of Stock Enhancement Schematic explanation of roles in farming fisheries in Japan (after Japan Fisheries Agency). JASFA denote Japan Sea-Farming Association
National Centers for Stock Enhancement (NCSE) 1. Akkeshi Stn. 2. Miyako Stn. 3. Notojima Stn. 4. Obama Stn. 5. Miyazu Stn. 6. Minami-Izu Stn. 7. Tamano Stn. 8. Yashima Stn. 9. Hakatajima 10. Momoshima 11. Komame Stn. 12. Kamiura Stn. 13. Shibushi Stn. 14. Goto Stn. 15. Yaeyama Stn. 16. Amami Stn.
Locations of Prefectural Stock Enhancement centers
II. Procedure and technology needed for restocking A case study on the Kuruma Prawn
Objective of Stock-enhancement of Kuruma prawn in Japan Recovering of the decreasing of catch To maintain a suitable catch level for fishermen The decreasing of catch in the 1960s were caused by land reclamations for development of industries. Necessarity of socioeconomic analysis of the area We have realized to improve the minimum annual catch level to maintain the mean annual catch level by restocking (Lake Hamanako)
Objective-Recovering of the decreasing of catch Importance of clarifying causes the decreasing of catch The life cycle study of black tiger prawn in the target area is essential. Is it able to recover the stock by restocking? - It should be dependent on the cause of the decreasing of catch In Japan, the catch decreasing of Kruma prawn were caused by land reclamation. It means that land reclamation destroy the nursery ground, and cut off the habitat sequence of Kuruma prawn.
Objective - To maintain a suitable catch level for fishermen To clarify the socioeconomic role of the target species in the area It should be essential to establish the ideal annual catch level I analyzed the economic role of the Kuruma prawn in the Hamana-ko district. I determined the suitable annual catch level as 67t, and 47t as minimum annual catch level, depending on the protocol with the Hamana Fishermen's Cooperation Association. It was necessary to introduce 20 million hatchery-raised Kuruma prawn juvenile with L 15mm per year.
Schema of the Life Cycle of Kuruma Prawn After Kurata (1986), modified. Plamktonic Life; Transportation by Current orn in early spawning Season August to November June to July 2-3 Age, Adult Spawning Area ( Open Sea ) Settlement; Nursery Ground Adolescent ( Immediate Coastal Zones of Estuary, Shallows ) Migration orn in Late Spawning Season 1 Age, Adult Spawning Area ( Shallow Open Sea ) Migration i
The environmental condition as key issue for stock enhancement (2) Key issue 1 Habitat sequence corresponding to the life cycle Kuruma prawn Settlement; 7-10mm Immediate coastal zone of estuarine Adolescent; 30-50mm Shallows Migration after Mating; Shallow open sea connecting to shallows 2-3 age adult; Open sea connecting to shallow open sea
When, Where, and How to introduce the hatchery-raised juvenile to the nursery ground for acclimation rearing to improve the effectiveness of restocking To improve adaptability for the natural environmental condition at releasing area To improve the health and quality Acclimation Transportation Releasing/Recruitment Hatchery Nursery Fishing ground Mortality 1 Mortality 2 To eliminate the mortality Mortality 1 1. To improve the quality 2. To develop the transportation technique Mortality 2 1. To clarify the causes of mortality 2. To improve the acclimation rearing technique
Scheme of Survival Curve of Accumulation Rearing Individual Number N 0 N a N r N0 ; Individual Number at time t 0 N a ; Ind. N. at time t a N r ; Ind. N. at time t r t 0 t a T i m e t r t 0 ; Time of introducing t a t r ; End point of mortality of introducing ; Time of release
Introducing Mortality in Acclimation Severe Mortality occurred at post-introducing to the nursery for acclimation - occurring in 24hours after introducing Caused by; 1. Low quality of hatchery-raised juvenile 2. Low transportation technique 3. Tidal condition at introducing 4. Predation
Mortality in Acclimation Procedure Usually, mortality in acclimation procedure is lower than Introducing mortality To improve acclimation rearing technique; presence of the density dependent effect on growth and mortality Survival rate is depending on the period of acclimation rearing To evaluate the effect by predation To determine the releasing size depending on the ecology of juvenile
Factors for success of stock enhancement (1) Releasing technique as an issue of man, (1) Development of transportation, acclimation, and releasing technique (2) Quality of fish as an issue of seedlings, and (2) Development of technology on improvement of the fish health and the fish quality (3) The environmental condition as an issue of the field for stock enhancement. (3) Improvement of knowledge of fishery biology and ecology
(1) Releasing technique as an issue of man Development of transportation, acclimation, and releasing technique Mainly depending on the quality of hatchery-raised seed Improvement of physiological and ecological characteristics of hatchery-raised seed
(2) Quality of fish as an issue of seedlings Development of technology on improvement of the fish health and the fish quality Essential: Standardization of rearing technique under laboratory condition, i.e., Growth and survival rates were affected by density dependent effect; Presence of optimum introducing density at mouth opening for red sea bream, Japanese flounder, and etc.
Physiological and ecological characteristics of hatchery-raised juveniles Fish health is defined physiological wellness of hatchery-raised juveniles, and fish quality is defined ecological robustness of them such as behavioral and feeding activity. The fish quality means ability to adapt to natural conditions in released environments. Fish health must be the prerequisite of the hatchery-raised seed for release. It is measured by physiological and morphological characteristics of fish, i.e. biochemical compositions of body, tolerance of stress in handling and environmental change and morphological normality. Fish quality is concerning an aptitude for release. It is the key factor of survival in the field after release and stocking effectiveness.
Fish health and quality as key issue for improvement stocking effectiveness The morphological and physiological attributes of the cultured fish together constitute a measure of health and that health combined with behavior represents fish quality. Fish quality or ecological robustness, is defined as the ability to adapt to natural conditions at release sites.
(3) The environmental condition as key issue for stock enhancement. Improvement of knowledge of fishery biology and ecology Relation between Life cycle and environmental conditions; Planktonic life Settlement; Presence of transitional period from planktonic to benthic life (Kuruma prawn, Mud crabs, Swimming crab, Japanese flounder) Presence of drastic change of feeding habits; to omnivorous (red sea bream), fishvorous (Japanese flounder)
Factors affecting the result of acclimation - 1 Effect of size at introduction for acclimation rearing the relation between mean body length and weight and survival rate during acclimation rearing carried out in the Lake Hamana (Fushimi 1986). oth plots are dome-shaped. The maximum survival rate was attained at a mean body weight of 30-50mg and a mean body length of 14-15 mm. Postlarvae with a L of 14-15 mm had a body weight of 28.5-32.7mg.
Factors affecting the result of acclimation - 2 Density dependent effect on survival and growth in acclimation procedure The natural mortality coefficient per 5 days, M 5 rose linearly when the density was increased from 100 to 400 individuals per m 2, but became asymptotic above 400 individuals per m 2. The plot of daily growth rate on rearing density was dome-shaped, with a peak of 1.5 mm per day at 200 to 300 individuals per m 2. Therefore, the optimum density for introduction of seeds to the acclimatization enclosure was determined as 200 to 300 individuals per m 2 (Fushimi 1983).
Factors affecting the result of acclimation - 3 Effect of predation in acclimation procedure The mortality due to predation (Mg) was determined using the relationship (M =M+Mg). M and Mg have the same value when the stocking density is about 170 individuals per m 2. Predation by gobies has a more severe effect on survival than density-dependent natural mortality at densities below 170 individuals per m 2.
Release after Acclimation Procedure - 1 The body size and time of release affected to the recovery rate of released hatcheryraised seeds. Conditions affected to establish the strategy of release The body size is closely related to development of behavioral characteristics. Ability of hatchery, transportation apparatus, environmental conditions of releasing area, acclimation procedure, releasing technique, etc.
Release after Acclimation Procedure - 2 Timing of release important issue for stocking effectiveness The technological development of bloodstock management, especially induced spawning technique. Manipulating temperature and photoperiod for induced spawning.
How to detect the restocking effectiveness -1 Collaboration of fishermen Restocking effectiveness improve fisheries productivity Fundamental information should be fisheries statistics It should be essential to develop the fisheries management for improvement of the restocking effectiveness
How to detect the restocking effectiveness -2 Importance of planning for research on restocking effectiveness arrow diagram of research should be essential asic research should composed by fishery biology and population dynamics on natural and released populations. Components of research; Fisheries statistics, composition of catch, distinguish of cohort, dispersal and migration, growth, natural and fishery mortality, and socio-economics
III. Progress in Production of Hatchery-raised Finfish Juveniles for Stock Enhancement Hatchery technology in Japan Development of larviculture were mainly supported by progress in iological studies on finfish and shellfish nutrition Rotifer production technique Aquaculture industries, such as plastic equipment, freshwater Chlorella. Logistics in keeping refrigerated.
Key Issue for Intensive Larviculture Hatchery Mechanization Marino-Forum 21(MF21) provides major support for the mechanization larviculture - Micro-formulated feed for fry - Mechanized closed continuous culture system of rotifer (Harvests of three billion S-type rotifer/ m3/ day) - Continuous culture system of L- type rotifer (1000 rotifers/ml, 60% harvesting/day
IV. Scale of Hatchery-raised Juveniles for Stock Enhancement in Japan Species Number Finfish Shellfish
Species Number of Larviculture and Release for Stock Enhancement in Japan
Pisces; Individual Number of Larviculture and Release in Japan
Red sea bream: Annual change of individual number of hatchery-raised seed production and release 35000 30000 Production Release 25000 20000 15000 10000 5000 0 Y e a r
Red sea bream: Annual change of individual number of hatchery-raised seed production and release
Changes in Catch and the Number of Red Sea ream Released in Kagoshima ay
Japanese flounder: Annual change of individual number of hatchery-raised seed production and release 45000 40000 35000 30000 25000 20000 15000 10000 5000 0 Production Release Y e a r
Japanese flounder: Annual change of individual number of hatchery-raised seed production and release
Restocking Effectiveness of Japanese Flounder in Ibaraki Prefecture
Size Frequency Distribution and Released Fish Mixing Rate of Japanese Flounder in Ibaraki Prefecture Released hatchery-raised flounder were definite easily by color abnormality of blind side. Mixing rate was attained almost 10-15%. Catch recovery caused by releasing hatcheryraised juveniles.
Crustacea; Individual Number of Larviculture and Release in Japan
Annual Catch Fluctuation of Kuruma Prawn, Penaeus japonicus, in Japan M M M MM M M M F F M M M M M F M M M F F M M M M M M MM M MM M M MMM M M F F M M F F F F F F F F F F F F F F F F F M M M M F F F F F F F F M MM F F F F F F F F F F H H H H H HHHHHH H H H H H H H H H H H H H H H Y e a r ƒ J H F M
Kuruma prawn: Annual change of catch and individual number of hatchery-raised seed production and release 600000 500000 400000 300000 200000 100000 0 Catch Production Release 4000 3500 3000 2500 2000 1500 1000 500 0 Y e a r
Kuruma prawn: Annual change of catch and individual number of hatchery-raised seed production and release (2)
New Challenge for the Resource Restoration Plan in Japan
Annual Catch and Production of Japanese Fisheries Catch in 10thousand t Production in trillion Yen Far seas fishery Offshore fishery Coastal fishery Marine Aquaculture 1960 1965 1975 1985 1994 2001 Inland fishery & Aquaculture
Fisheries Measures for FY2006 I. Measures for Securing Stable Supply of Fishery Products 1.Securing stable supply of fishery products for people s diet. 2. Appropriately preserving and managing fishery resources in the exclusive economic zone (EEZ) 3. Appropriate preserving and managing fishery resources outside EEZ 4. Conducting surveys and research on fishery resources 5. Promoting multiplication and aquaculture of aquatic animals and plants 6. Preserving and improving the living environment of aquatic animals and plants 7. Maintaining and developing fishing grounds outside the EEZ 8. Taking measures on fishery product imports and exports 9. Promoting international cooperation
Fisheries Measures for FY2006, contn d II. Measures for Sound development of Fisheries Industry 1. Fostering efficient and stable fishery business management 2. Promoting more efficient use of fishing ground. 3. Developing and securing human resources. 4. Compensation for damages caused by fishery disasters. 5. Achieving sound development of fishery processing industry and fishery distribution industry. 6. developing the infrastructure of fisheries industry 7. Developing and diffusing technology 8. Promoting participation of women 9. Promoting activities of the elderly 10.Achieving comprehensive development of fishing ground 11.Making exchanges between cities and fishing villages 12.Increasing measures for optimizing the multiple functions
We have almost 40 years history, experiences on stock enhancement and fruitful results of stocking effectiveness.however, we have to consider possible unfavorable biological effects of large numbers of release hatchery-raised juveniles. We have to establish the more sufficient way to recover the status of fisheries resources or stocks. We have to pass on to coming generations the abundant fisheries resources or stocks.
Thank you for your kind attention!!
Pacific herring: Annual changes of Production and release of Hatchery-raised juvenile and catch
lack sea bream: Annual change of individual number of hatchery-raised seed production and release 12000 10000 8000 Production Release 6000 4000 2000 0 Y e a r
lack sea bream: Annual change of individual number of hatchery-raised seed production and release
Pacific herring: Annual change of individual number of hatchery-raised seed production and release
Pacific cod: Annual changes of Production and release of Hatchery-raised juvenile and catch
Sea bass: Annual change of individual number of hatchery-raised seed production and release 1800 10000 1600 Production Release 9000 1400 8000 1200 Catch 7000 1000 800 6000 5000 4000 600 3000 400 2000 200 1000 0 198419851986 198719881989 19901991 199219931994 19951996199719981999 Y e a r 0
Individual Number of Production and Release of Hatchery-raised Mud Crab, Scylla tranquebarica 1400 1200 Production Release 1000 800 600 400 200 0 1979 1980 1981 1982 1983 1984 1985 1986 1987198819891990199119921993 Y e a r
1600 Individual Number of Production and Release of hatcheryraised mud crab, Scylla oceanica. 1400 Production Release 1200 1000 800 600 400 200 0 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 Y e a r
Sea Urchins: Annual change of individual number of hatchery-raised seed production and release 100000 90000 Catch(Sea Urchins) 25000 80000 20000 70000 60000 15000 50000 40000 10000 30000 20000 Production Release 5000 10000 0 0 Y e a r
Annual change of catch (kg ) and release (inds.) of Kuruma prawn,penaeus japonicus, in the Hamana-ko 12,000,000 10,000,000 8,000,000 J Catch (kg) Number of released postlarvae (inds.) J J J J J J J J 110,000 100,000 90,000 80,000 6,000,000 4,000,000 J J J J J J J J J J J J J J J J J J J 70,000 60,000 50,000 40,000 2,000,000 0 J J J J J 1965 1970 1975 1980 1985 1990 1995 Year 30,000 20,000 10,000
Problems and Prospects Possible unfavorable biological effects of large numbers of release hatchery-raised seed Prospects The spread of pathogens, Competition for foods and cannibalism, Genetic deterioration of wild stock Improvement of fish quality would enable us to reduce the number of hatchery-raised seed and This minimize negative impacts of release on the environment.
Problems and Prospects (2) (1) The spread of pathogens Important issue; Development of prevention technology of the spread of Pathogens. JASFA has been engaged in this issue to take preventive measures against epidemic diseases of finfish (Arimoto, 1999)
Fluctuation of annual catch of Japanese swimming Crab, Portunus trituberculatus,in Japan Total F Middle Pacific Western Japan Sea J Hokkaido Southern Pacific Eastern China Sea H Northern Pacific ƒ Northern Japan Sea M Seto Inland Sea 6,000 5,000 4,000 3,000 2,000 1,000 0 M M M M M M M M F M M M M M M M M M M F F F F F F F F F F F F F ƒf ƒ F H H ƒ F ƒf ƒ ƒ H H H H H H H H H H H H H H H H H HJ H H HJ HJ HJ H H J H J H H H H H H H F F ƒ ƒ ƒ F F F ƒ ƒ ƒ M M M ƒ M M M M M ƒ ƒ ƒ ƒ ƒ ƒ F F F ƒ ƒ ƒ ƒ ƒ F F M F F F F F F ƒ ƒ ƒ ƒ ƒ J J J J J F ƒ ƒ ƒ ƒ ƒ ƒ M M M M M M M M J Y e a r
Swimming crab: Annual change of catch and individual number of hatchery-raised seed production and release 70000 60000 50000 40000 30000 20000 Catch (t) Production (1000 inds) Release (1000 inds) 6000 5000 4000 3000 2000 10000 1000 0 0 Y e a r
Swimming crab: Annual change of catch and individual number of hatchery-raised seed production and release
Problems and Prospects (3) (2) Competition for foods and cannibalism, Establishment of fish quality improvement technology However, some trials conducted to establish fish quality improvement technology of larviculture, we could not establish effective larviculture system improving fish quality. Application of biocontrol method, which developed in swimming crab larviculture, should encourage developing future larviculture system improving fish quality.
Problems and Prospects (4) (3) Genetic deterioration of wild stock WWe have to encourage to conduct studies on this field, because we have little information on this issue (Harada, 1999). WWe have to use the wild organisms as bloodstock, and to improve the quality of hatchery-raised juveniles