Qingdao fish farmers culling invasive starfish

Authorities in the coastal city of Qingdao, Shandong province, have given local fish farmers permission to cull starfish en masse that have invaded the seashore, as the growing population of the sea creature has led to heavy losses to the clam and oyster industry in the area.

As invading starfish feed on clams and scallops, an area of 6,666 hectares of sea farming has been affected, with economic losses estimated at about 100 million yuan ($15.4 million) at Jiaozhou Bay, according to the Qingdao Municipal Marine Development Bureau.

The local government reported to the provincial department of agriculture and rural affairs that farmers are allowed to trap starfish or use trawls to haul them from March 15 to the end of April in order to reduce losses.

As starfish are difficult to catch, city authorities are even allowing farmers to set up cage nets－which are otherwise prohibited－to trap them.

With the efforts, local farmers have harvested about 225,000 kilograms of starfish so far.

"Buyers from other cities are coming to purchase the starfish, which are edible and can be used in traditional Chinese medicine. But the sales cannot make up for the farmers' losses due to the low price," said Zhao Yuchang, a local breeder of sea creatures with more than 30 years of experience.

The time has come for the farmers to release the clam seedlings, but they are too afraid to do so in large quantities as there are about 50 starfish per square meter in the release area. "I dare not do it now, but without the seedlings, I will have no income next year," Zhao said.

Technicians of the North China Sea Environmental Monitoring Center said the invading starfish are mainly spiny starfish widely distributed in the coastal waters of the North Pacific Ocean. They are very fertile and usually breed from October to January.

Since autumn, various hydrological factors such as nutrients, pH values and temperatures in the seawater have been conducive to the reproduction of starfish. Researchers found that starfish have the tendency to gather in food-rich areas, such as the mariculture farms in the bay area.

According to the monitoring center's latest data, the number of starfish had been reduced by 6 to 8 per square meter by Friday, thanks to massive netting.

Qingdao, the host city of an annual international beer festival in summer, one of the largest in China, produces 150,000 metric tons of clams a year. Stir-fried clams, a local delicacy, are a staple at the event.