TIANJIN, June 11 (Xinhua) -- As a crab farmer with 36 years of experience, Du Naihe is fascinated with a more profitable and environmentally friendly way to farm crabs.

Du has found that farming crabs in paddy fields has a lot of advantages compared with traditional crab farming. "It not only earns me extra income from the rice crop, but provides a better environment for the growth of crabs," Du said.

Du lives in a village near the wetland of Qilihai in Ninghe District, north China's Tianjin Municipality. The villagers, including Du, used to make a living by farming fish or crabs near a wetland.

In 1984, Du leased 50 hectares of wasteland near the wetland to farm crabs. He also cooperated with professors from Tianjin Agricultural University to improve the quality of his product. "My crabs are always in great demand and customers must place an order for them in advance," he said.

Other villagers followed suite. Fish and crab farming and the development of tourism increased the income of the villagers.

However, unregulated development had damaged the wetland, leading to shrinkage in wetland area, lower water level and poor water quality. "We intended to make good use of the wetland to enrich the villagers, but uncontrolled development and use of pesticides as well as poor management of rubbish damaged the environment," said Chen Li, director of the wetland's management committee.

In 2017, relevant departments began to solve the ecological problems of the wetland, restoring the environment with a slew of projects including diverting water to the wetland from elsewhere. Du and other villagers withdrew from the wetland. Some of them found new jobs with the government's help.

But Du is obsessed with crab fishing. He found a new way: farming crabs in rice fields. "The ecological relationship between rice and crabs helped reduce the use of pesticides and crab feed," Du said. He leased more than 6.67 hectares of land outside the wetland for the integrated rice and crab farming in 2019.

"The revenue is expected to exceed 500,000 yuan (about 70,813 U.S. dollars) this year judging from the output last year, which is higher than traditional rice or crab farming," he said. Du is also exploring how to improve the quality of crabs and develop other crab products.

"The water quality of the wetland has greatly improved after banning the use of pesticides and other pollutants," said Chen. "More than 400,000 birds, including nearly 1,000 rare oriental white storks under national first-class protection, were monitored at the wetland last year."

More than 10,666 hectares of fields for the integrated farming in the district will add 100 million yuan of output value each year compared with traditional rice farming, said Wang Jin, director of the district's committee of agriculture and rural affairs.

"I want to set an example for other farmers, encouraging them to reduce the use of pesticides and produce healthy agricultural products," Du said. "I also hope to sell my own products abroad in the future." Enditem