After 50 Years, Why is Artificial Breeding of Eels Still So Challenging for China? (AI Translation)
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文｜财新周刊 周泰来 包云红，韩宇昂（实习）
By Caixin Weekly's Zhou Tailai, Bao Yunhong, Han Yu'ang (Intern)
每年10月的中下旬，西风来临，温度变低，上海海洋大学教授刘利平会带研究生去江苏沿海收鳗鱼。他们要提前联系好中介，让渔民把捕来的野生鳗鱼汇总到一起，然后由他们去挑。
Every year in late October, as the west wind arrives and temperatures drop, Professor Liu Liping from Shanghai Ocean University leads his graduate students to the coast of Jiangsu to collect eels. They must arrange in advance with intermediaries to have fishermen gather the wild-caught eels, which they then select from.
刘利平需要的不是一般的鳗鱼，而是将要洄游到大海里去繁殖的银鳗。银鳗是鳗鱼一生的最后阶段。此时的它们腹部银白色，胸鳍深黑色，已经为洄游储存足够多的能量，不再进食。刘利平收的雌鳗一般重700多克、长70多厘米，雄鳗则只有一半大小。
Liu Liping is not in need of just any eel, but specifically the silver eel that is about to migrate to the sea for spawning. The silver eel represents the final stage in an eel's life cycle. At this point, their bellies are silvery white and their pectoral fins are deep black, having stored enough energy for migration and ceasing to feed. The female eels Liu collects generally weigh over 700 grams and measure more than 70 centimeters in length, while the males are only half that size.
由于是野生的鳗鱼，渔民们要价往往高达200元每斤。刘利平一般会收200条左右，收一次就要花大几万元。随后他会把这些鱼用控温的活鱼车送到上海海洋大学附近的基地暂养。
Due to the eels being wild-caught, fishermen often demand prices as high as 200 yuan per jin (approximately 500 grams). Liu Liping generally purchases around 200 eels at a time, spending tens of thousands of yuan per batch. He then transports these fish in a temperature-controlled live fish vehicle to a temporary holding facility near Shanghai Ocean University.
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- Professor Liuping Liu from Shanghai Ocean University leads research on artificial breeding of eels, focusing on the silver eel stage for reproduction. Despite advancements, China's technology lags 30 years behind Japan, which has achieved full-cycle artificial breeding of eels.
- The global demand for eels is high, with Japan being the largest consumer and importer. China dominates in eel farming and export but relies heavily on wild-caught juvenile eels, posing sustainability challenges.
- Efforts to artificially breed eels in China face significant hurdles due to lack of funding and technical challenges in mimicking natural conditions for eel maturation and finding effective initial feed for hatchlings.
Professor Liu Liping from Shanghai Ocean University leads annual expeditions to collect silver eels in Jiangsu, which are crucial for his research on artificial eel breeding. These eels, caught during their migration phase for spawning, are selected based on size and weight, with significant costs involved due to their wild-caught nature [para. 1].
Liu's research focuses on inducing gonadal development in these eels to facilitate spawning and study juvenile survival. Despite extensive efforts and advancements allowing juvenile eels to survive up to 21 days, China still lags behind Japan by about 30 years in this field. Japan has achieved full-cycle artificial breeding of eels since the early 2000s and aims for all artificially bred larvae by 2050 [para. 2][para. 3].
China is a major player in global eel farming and exports but relies heavily on capturing natural larvae, posing sustainability challenges. Efforts to advance artificial breeding have been hindered by funding shortages and technical difficulties, despite the industry's substantial economic impact [para. 4][para. 5].
Historically, local fishermen undervalued eel fry until demand increased dramatically in the 1990s, leading to overfishing and resource depletion. Current catches are significantly lower than past decades, reflecting ongoing sustainability issues [para. 6].
Eel smuggling has become a serious problem due to high demand and limited resources. Recent incidents highlight the challenges faced by authorities in controlling illegal activities that exacerbate the strain on eel populations [para. 7].
Efforts to protect eel populations include imposing fishing bans and enhancing scientific research. However, these measures face obstacles such as insufficient funding and lack of comprehensive management strategies across different regions [para. 8].
The complex lifecycle of eels involves long migrations from freshwater habitats to oceanic spawning grounds. Understanding these patterns is crucial for effective conservation and management but is impeded by technological limitations and financial constraints [para. 9].
Despite international cooperation efforts and technological advancements like Pop-up Archival Transmitting tags to track migrations, significant gaps remain in knowledge about eel behaviors and needs during different life stages [para. 10].
In conclusion, while there have been some progress in understanding and protecting eels through artificial breeding techniques and conservation measures, much work remains. Enhanced collaboration between governments, researchers, and industry stakeholders is essential to address the multifaceted challenges facing this valuable yet vulnerable species [para. 11].
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