Crabs clawing their way up on green island
In Chongming, fall is the ideal time for people to saunter along fragrant rice paddies or enjoy gourmet crab under tangerine trees with ripe fruit.
The opening ceremony of the Ecological Culture and Tourism Festival held in Luhua Town earlier this week marked the beginning of this year’s hairy crab and harvest season.
The festival’s mascot, Xiaojiadi, which means “little bro” in Chinese, is a small local freshwater crab that’s said to bring wealth and good luck.
The freshwater crab industry is booming in Chongming, birthplace of Chinese mitten crabs.
Relatively new to the public compared to Yangcheng Lake hairy crabs, this indigenous local crustacean is now favored by many for its flavored roe and flesh — the result of recent breeding improvements.
With a breeding area of 4,000 square meters, the amount of crabs produced at Baodao Crab Farm in Luhua is 10 percent higher than last year.
According to the farm’s crab keeper Huang Chun, crabs bred here are getting bigger, with an average size of 225 grams.
“Freshwater crabs have to shed 18 to 21 times to be considered mature,” Huang said. “Due to this year’s hot summer, they shed more often, so it took longer for them to grow up.”
Huang’s farm applied an internal-circulation breeding model that minimizes water pollution.
Instead of emitting crab-pond water directly into a ditch and lake as dictated by traditional methods, farmers now drain crab-pond water into farmland and wooded areas so the water can be treated via biological filtering.
The farm planted 8,000 pond fir and cypress plants — covering 5,700 square meters — on three artificial islands to improve the crabs’ growth environment.
“These water plants effectively adjust the water temperature during the crabs’ growth process, which makes them more comfortable when it’s hot,” Huang said. “Trees also help by absorbing silt which prevents eutrophication (excessive minerals and nutrients that leads to extreme algae growth).”
The farm has adopted new seedlings selected from Yangtze River crabs by researchers at Shanghai Ocean University.
Despite that it’s been pummeled by COVID-19 this year, Chongming has sought greater opportunities in the aquatic-product industry by expanding sales channels and developing new products.
During the festival, Shanghai Baodao Crab Company signed an agreement with Shanghai Greenland Group to supply more of its crab-related products to supermarkets.
Freshwater crab will be a licensed product at the 10th China Flower Expo which will take place on Chongming Island in 2021.
Famous for its high-quality hybrid rice with a rich taste and smell, Chongming has been exploring eco-friendly production methods instead of using chemical fertilizers and pesticides.
“The traditional vegetable-planting model tends to have a negative effect on the environment,” said Zhang Feng, deputy chief of the Chongming District Agriculture Committee. “As food safety and green ecosystems are under stress, we need to explore eco-friendly growing methods to meet consumer demand.”
To breed high-quality rice, hand weeding, organic fertilizers, biological pesticides and solar-powered bug zappers are used during the growing process.
At some farms, shrimp and turtles are used for low-density rice planting, forming an ecological cycle for pest control.