No abstract

Global eel production has dramatically increased over the last 30 years because of the expansion of eel farming. In 2018, 47 countries were engaged in eel production, with a total output of 277,103 metric tons and a total value of US$2.67 × 10 9 for eel imports and exports. To better understand the development status of the eel industry, especially in China, and to protect glass eel resources and promote the healthy development of the industry, we summarize the current development status of eel culture in terms of eel production, natural recruitment, imports, and exports. Japanese and Chinese production, imports, and exports are the main focus of this study. The eel production industry is characterized by high investment, high risk, and high returns. Since the mid-1990s, China has been the world's leading country for eel culture in terms of yield, accounting for over 80% of global yield. The profit margin is over 60% for eel farming in China. Japan has a long history of eel culture, and it is the dominant consumer market for eels, with 50% of the world's consumption. Countermeasures and suggestions are proposed to promote the development of the eel industry due to severe problems, such as declines in wild glass eel recruitment since 2018, an increasing demand for eels, the excessive dependence on exports to the Japanese market, and the effects of environmental protection policies on the eel industry in China. These measures include protecting eel germplasm resources and developing other cultured varieties as well as developing international emerging markets and cultivating domestic markets to strengthen the eel brand. Furthermore, trade associations should be developed in order to provide information for farmers and strengthen interactions with the government.Eels Anguilla spp. are among the most common fish cultured throughout the world. Eels are high-quality, edible fish with high protein and fat contents. They taste delicious and are highly nutritious (Chen 1990). Since ancient times, eels have provided a precious food source for the people of China. Indeed, eels have a reputation as "ginseng in water" and they are highly regarded by Asian consumers. Eels are also among the most important aquatic products in international trade, and they command high prices (Muthmainnah et al. 2016). Thus, eels make important contributions to the development of the fisheries economy.According to the Food and Agriculture Organization of the United Nations (FAO; FAO 2020b) Global Fishery and Aquaculture Statistics, the economically important eel species are the Japanese Eel A. japonica, European Eel A. anguilla, American Eel A. rostrata, Shortfin Eel A. australis, and Speckled Longfin Eel A. reinhardti. In recent years, the output from eel culture has increased throughout the world, but the total output has now stabilized at about 270,000 metric tons. The main eel production areas are concentrated in Asia, including China, Japan, South Korea, Taiwan, and other regions, followed by Europe, Africa, and the United States. The Japan...

China is the world's largest tilapia producer. This study uses the stochastic frontier function in the Cobb–Douglas model to evaluate a production frontier for tilapia aquaculture and analyses the relationship between farm size and production efficiency in China. A random sample of 300 tilapia farmers was surveyed in the main tilapia‐producing areas to study their economic efficiencies. The percentage distribution of tilapia farm technical efficiency was determined, with an average efficiency of 79%, which showed that the sample tilapia farmers operate at 21% below the production frontier and hence that they still have a chance to achieve targeted yields. The technical efficiencies of two categories (≤1 ha and >1 ha) were 78.82% and 79.27% respectively. A second‐stage analysis investigated the relationship between farm size and technical efficiency and showed a positive relationship between farm size and production efficiency based on the ordinary least‐squares model. The optimal farm size was found to be 7.50 ha. This study proposes strategies such as enlarging the farming scale moderately, thereby achieving the advantage of economies of scale, and enhancing the competitiveness of the tilapia industry in China.

The effect of gibberellic acid (GA3) and 6‐benzylaminopurine (6‐BA) on lignification of fresh‐cut Zizania latifolia were investigated for 15 days at 1C. Results showed that treatment of Z. latifolia slices with GA3 and 6‐BA slowed down the increase in cellulose and lignin contents, maintained relatively high cellulase (CEL) activities and total phenol contents. Both treatments also inhibited phenylalanine ammonia‐lyase, 4‐coumarate CoA ligase, cinnamyl alcohol dehydrogenase and peroxidase activities. GA3 treatment promoted the accumulation of superoxide anion radical (O2·‐) and hydrogen peroxide (H2O2) over the first 9 days of storage but reduced their accumulation after 9 days of storage. 6‐BA treatment significantly inhibited O2‐ and H2O2 accumulation throughout storage period. These results indicated that GA3 and 6‐BA could retard lignification thereby maintaining a better texture of fresh‐cut Z. latifolia during storage at 1C, which provides a theoretical basis for commercial application. PRACTICAL APPLICATIONS The marketing of packaged and refrigerated fresh‐cut Zizania latifolia is a choice of increasing interest for vegetables processors. However, fresh‐cut Z. latifolia have a faster rate of lignification during retail because of wounding. Therefore, this study was conducted to develop treatments to reduce tissue lignification of fresh‐cut Z. latifolia. Results showed that GA3 and 6‐BA treatments can effectively inhibit lignification in fresh‐cut Z. latifolia, which provides a theoretical basis for commercial application.

No abstract