Zhou Liang has achieved the first successful freshwater breeding and spawning of Chinese sturgeon by humans. (Photo/Sichuan Changning)

Chongqing - The Yangtze River once faced an ecological crisis marked by declining fishery resources and the near-extinction of rare species. To reverse this, Zhou Liang and his father Zhou Shiwu dedicated themselves for 30 years to the breeding, protection, and artificial reproduction of rare species in the Yangtze.

In September 1993, after graduating from Sichuan University, Zhou Liang followed his father's footsteps to Sichuan Changning, where they began artificial breeding experiments on endangered Yangtze species, including the Chinese sturgeon, Yangtze sturgeon, and red-bellied fish, at the Yibin Rare Aquatic Animal Research Institute.

Father and son devoted themselves to researching fish breeding theories and putting them into practice. Liang’s persistence stemmed from a simple belief: all our efforts are worth it, as long as the rare fish of the Yangtzi don't go extinct."

The Chinese sturgeon, Yangtze sturgeon, and red-bellied fish are endemic to the Yangtze River and highly sensitive to water quality, habitats, and hydrological changes. Overfishing, habitat loss, and altered hydrology caused their populations to plummet, pushing them to the brink of extinction.

Compared to common fish, these species mature later, have long breeding cycles, and require specific water conditions, making artificial reproduction and offspring survival challenging. As a result, artificial breeding of them has become one of the most difficult research challenges in protecting the Yangtze’s rare fish.

At the start of their venture, they had to begin from scratch. They traveled to the Jinsha River Valley and the upper Yangtze River to investigate fish resources, once hiking 48 kilometers in a single day over mountain roads.

The hardships were immense. Even more challenging was that purchasing breeding fish and establishing a facility exhausted Shiwu's savings over the years. At one point, the breeding farm survived solely on Liang’s mother's modest monthly salary of 300 yuan (43 U.S. dollars) as a teacher.

In the summer of 1994, a rare drought caused the institute’s live food supply to run out. To save the breeding fish, Zhou Liang would spend every day digging for earthworms in the mountain ravines, eating dry steamed buns when hungry and drinking spring water when thirsty, working from dawn to dusk.

On days when earthworms were not available, he would put on rubber pants and manually search for nematodes in the stinky ditches, with the unbearable odor under the scorching sun making it nearly impossible to open his eyes. Yet, he never backed down. Thanks to his careful care, the breeding fish ultimately survived.

On one occasion, when purchasing red-bellied fish, they were dismissed and mocked  as "amateurs dreaming of doing high-tech aquaculture research." Despite facing mockery and misunderstandings, they refused to give up. For five consecutive days, they stayed outside the breeding base of the red-bellied fish, earning the managers' trust and support through their sincerity, and eventually succeeded in purchasing the long-awaited fish.

Zhou Liang led his team to prove their critics wrong through action, achieving breakthroughs in protecting rare fish in the Yangtze River, especially in the artificial breeding of the Yangtze sturgeon. In 1998, they successfully bred Yangtze sturgeon in an indoor pond. In 2004, when wild Yangtze sturgeon were nearly extinct, they achieved large-scale breeding of the species.

In 2007, the team overcame the technical challenges of all-artificial breeding for the Yangtze sturgeon, paving the way for rebuilding wild populations. From 2018 to 2020, they achieved natural spawning in indoor group ponds, boosting the restoration of the wild population and the Yangtze's ecology. Over the past three decades, the institute has released 1,000 Yangtze sturgeon breeding fish and 660,000 fry back into the Yangtze River.

Beyond the Yangtze sturgeon, Liang’sang's team has also released 30 Chinese sturgeon, 500,000 red-bellied fish fry, and 540,900 rock carp fries into the river, effectively boosting the population and genetic diversity of rare fish species in the upper Yangtze. These efforts have contributed to replenishing the Yangtze's aquatic biological resources, leading to the restoration of endangered species and enhanced biodiversity.

(Credit to the Publicity Department of the Party Committee of Changning County, Yibin City, Sichuan Province)