Eel and flat fish culture --The present status and sustainable development of eel and turbot culture in China

Transcription

1 Eel and flat fish culture --The present status and sustainable development of eel and turbot culture in China Tongjun Ren, Mingling Liao College of Fisheries and Life Science, Dalian Ocean University, China

2 Eel

3 The production of Japanese eel (t) The production of Japanese eel 250, , , , ,000 0 China Japan Korea Taiwan Data source: FAO

4 The value of Japanese eel production (USD 1000) The value of Japanese eel production 600, , , , , ,000 0 China Japan Korea Taiwan Data source: FAO

5 The stocking volume of Japanese eel (t) The stocking volume of Japanese eel China Japan Korea Taiwan Data source:

6 Eel marketing Live eel export of China Export volume (t) Unit price ($/kg) 80-85% Growth rate (%) Growth rate (%) Japan 5,505 3, Hong Kong Korea Total 7,000 3, Data source: China customs

7 Eel marketing Grilled eel export of China Export volume (t) 60% Unit price ($/kg) Growth rate (%) Growth rate (%) Japan 19,658 19, Hong Kong 785 2, Korea USA 4,221 3, Russia 3,421 4, Singapore Germany Total 33,318 34, Data source: China customs

8 Eel culture system Pond culture Low cost Low power & water consumption Easy to master the technique Low production Difficult to prevent and cure disease Uncontrolled temperature

9 Winter insulation

10 Eel culture system Industrial culture High production Short culture cycle Low water consumption System stability High cost High technique required Advanced Equipment required

11 Eel culture system Cage culture An intensive culture and affects enormously the ambient waters. A newly-developing culture system in southern China, whereas the proportion is relatively small.

12 Eel nutrition Protein & Fishmeal replacement García-Gallego et. al (1998); Higuera et. al (1999); Tibbetts et. al (2000) Optimum dietary protein level for juvenile American eel % Replacement study: Meat meal Sunflower meal etc.

13 Eel nutrition Lipids Gunasekera et. al (2002); Agradi et. al (1995); Furuita et. al (2007) Lipid source affect lipid digestibility of Australian short fin eel; Cod liver oil diet----- highest lipid digestibility. Fish oil and vitamin E supplements can contribute to the accumulation of physiologically important lipid components affecting the mechanisms controlling ammonia excretion in stressed animals. Both n-3 and n-6 fatty acids are necessary for reproduction as well as growth of eel brood stock, and a higher ratio of n-6 to n-3 fatty acids negatively affected embryogenesis.

14 Eel nutrition Digestibility Suárez et. al (1995); Degani (2004); Tibbetts et. al (2002) European eel showed a certain capacity to adapt intermediary metabolism to changes in diet composition. The digestibility of energy in wheat meal was 97.11%, in corn meal 40.13%, in sorghum meal 42.66%, in potato meal 63.25%, in potato starch meal 96.66% and in cottonseed meal 46.51%. The optimum digestible protein/digestible energy (DP/DE) ratio for juvenile American eel was 22.1 g DP/MJ DE.

15 Eel nutrition Vitamin C and others Ren et. al (2005); Ren et. al (2007); Hirt- Chabbert et. al (2012); Lee et. al (2013) Optimum dietary level of ascorbic acid (AsA) for juvenile Japanese > 27mg AsA/kg. Vitamin C and lactoferrin could improved blood chemistry and nonspecific immune function of Japanese eel. The incorporation of feeding stimulants into a pelleted diet was beneficial on the overall performance of European glass eels and elvers. Lactobacillus pentosus PL11 is a potential alternative to antibiotic supplementation to improve the growth and health performance of Japanese eel.

16 Eel Feeding

17 Turbot

18 Turbot Scophthalmus maximus L * The most important culture species of flat fish * High market price 9-12 USD/kg

19 Turbot production 80,000 Aquaculture production of turbot in China World total except China 70,000 60,000 50,000 40,000 30,000 20,000 10,000 (Ton) Year Lei et al., 2012

20 Turbot seedling EU: 10,000,000 N/ year Number of hatcheries, tank area and seedlings of turbot produced in China Year Number of hatchery Tank area Number of seedling (m 2 ) (x10 6 ind) , , ,

21 Turbot culture Vinyl house+ well sea water Tank area: 4,649,000 m 2 Seedling size: 6-10cm Density: N/m 2 + Water temperature: Salinity: DO: 4ml/L+ Market size: 700g+ Feeding period: 12 month

22 Turbot culture Net cage culture 2 Culture area: 156,200 m Production:1834 t

23 Turbot culture Recycling system *Typical culture model in EU *Future direction for China

24 Turbot nutrition Protein Ma et al. (2001); Chen et al. (2003); Cui et al. (2011); Mai et al. (2009); Ma et al (2009) Optimum dietary protein level >42% Optimum P/E level Fish meal replacement: Beer yeast; soybean meal; rapeseed meal etc.,

25 Turbot nutrition Lipid Ma et al. (2001); Bell et al. (1995); Sargent et al. (1999) Optimum lipid level % 22:6(n-3) level for juvenile >1% 22:6(n-3)/20:5(n-3) for larval :1 Carbohydrate Ma et al. (2003) Optimum dietary carbohydrate level %

26 Turbot nutrition Vitamins VE required Martinez-Tapia et al. (1993); Cowey et al. (1975); Adron et al. (1978); Merchie et all. (1996) VB mg/kg VB mg/kg VC mg/kg Minerals Chen et al. (2003) Zn mg/kg Cu mg/kg

27 Turbot Feeding +

28 Thank you