Qingdao fishermen in war against starfish

Authorities in the coastal city of Qingdao in east China’s Shandong Province have greenlighted a mass cull by local fish farmers of starfish, as a surge in the population devastates the clam and oyster industry in the area.

Invading starfish feed on clams and scallops.

An area of 6,666 hectares of sea farming has been affected.

Economic losses are estimated at about 100 million yuan (US$15.4 million) at Jiaozhou Bay in Qingdao, according to the Qingdao Municipal Marine Development Bureau.

The municipal government reported to the provincial department of agriculture and rural affairs that farmers are to trap starfish or use trawls to haul them in until the end of April.

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

Local farmers have already harvested about 225,000 kilograms of starfish so far.

“Buyers from other cities are coming to purchase the starfish, which are edible or 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 aquatic products 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 invest now,” said Zhao. “But without the seedlings, I will have no income next year.”

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.

Its fertility rate is extremely high, and it usually breeds from October to January.

Since last autumn, various hydrological factors such as nutrients, pH value and temperature 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 to 6 to 8 per square meter by Friday, thanks to the massive netting of the invaders.

Qingdao, the host city of an annual international beer festival in summer, one of the largest in China, produces 150,000 tons of clams a year.

Drinking beer and eating the local delicacy of stir-fried clams are mainstays at the carnival.