Illegal fishing by Vietnamese boats around China's Xisha Islands has been on the rise in recent years, posing threats to the safety of Chinese fishermen and fish resources in the South China Sea.
About 237 Vietnamese vessels had been found illegally fishing in waters around the Xisha Islands by the end of May this year, an official with the coastal defense committee of Sansha City told Xinhua.
Many Vietnamese fishermen were caught by Chinese maritime authorities using dynamite and purse nets, which are banned under China's fishing regulations, he said.
Vietnamese were also caught on many occasions fishing protected sea turtles, added the official, who did not wish to be named.
According to data from local authorities, less than 20 Vietnamese vessels were found illegally fishing in waters around the Xisha Islands annually before 2000. The number rose to just under 100 vessels in 2004.
Since 2005, illegal Vietnamese fishing around the islands has been increasingly rampant, with authorities catching 319 such boats last year.
"Vietnamese fishing boats have constantly intruded into the waters of China's Xisha Islands this year. We encounter them almost every day," said Wang Shizheng, deputy head of the Sansha Law Enforcement Bureau.
In January alone, China's law enforcement officers caught 26 Vietnamese boats illegally fishing in these waters, driving away 10 of them and embarking onto four boats for inspections which resulted in the confiscation of 350 kg of dynamite, 447 detonators, 160 meters of fuse as well as fishing nets and other tools, according to Wang.
The number of Vietnamese fishing boats around the Xisha Islands peaks from January to March each year, straining at the resources of Chinese law enforcement officers, he noted.
Wang also explained that Vietnamese fishermen have come up with a tactic of putting their explosives into leather bags, attaching the bags to GPS buoys and throwing them into the sea to avoid them being found during inspections.
Meanwhile, according to Sansha City statistics, local maritime authorities there confiscated 4,624 kg of dynamite, 2,850 detonators, 1,057 meters of fuse and other fishing tools from Vietnamese boats fishing illegally in their area of jurisdiction between 2000 and 2011.
The illegal fishing, together with overfishing by the Vietnamese side, has caused worries of a possible destruction of the ecosystem in the South China Sea.
"Our country has a fishing moratorium, while Vietnamese fishing boats are all over the sea. Many of them are using light-seiners to catch fish. They are exploiting the fishery resources in a destructive way," said Chen Zebo, a fisherman from Tanmen, a fishing town in Hainan Province.
Chinese maritime authorities enforce a two-and-a-half-month fishing moratorium in the South China Sea each year to preserve fishery resources. The ban lasts from May 16 to August 1 this year.
In addition, armed Vietnamese fishing vessels have repeatedly looted Chinese fishing boats, posing a serious threat to the safety of Chinese fishermen's lives and property.
Dong Rongda and his brother Dong Rongping, fishermen from Danzhou City, Hainan, said they were robbed of more than 1,000 fishing nets worth 300,000 yuan (about 48,000 U.S. dollars) by six armed Vietnamese fishing boats in 2009.
Sansha City, on Yongxing, one of the Xisha Islands, was officially established in July 2012 to administer the Xisha, Zhongsha and Nansha island groups and their surrounding waters in the South China Sea.
Vietnam's policies, including high compensation for fishermen's losses in case of clashes with Chinese ships, have encouraged the infringement and illegal fishing activities, according to Feng Wenhai, vice mayor of Sansha City.
Vietnamese seized by Chinese law enforcement authorities for illegal fishing confessed that they were given large subsidies by the Vietnamese government to fish in "disputed waters." A vessel can get thousands of U.S. dollars from the government a year.
In its latest effort to encourage illegal fishing, Vietnam awarded a total of 400 million Vietnamese dong (about 18,800 U.S. dollars) to the captain of a fishing boat damaged in clashes with Chinese escort ships near a Chinese oil drilling rig off the Xisha Islands last month, according to Vietnamese media reports.
With government support, the number of fishing boats in Vietnam's four southeastern coastal provinces have increased from less than 1,000 in the year 2000 to 5,000 currently, with most of them operating intensively in the South China Sea, said Sun Xiaoying, a researcher from the Southeast Asia Research Institute under the Academy of Social Sciences of south China's Guangxi Zhuang Autonomous Region.
"Supporting policies of the Vietnamese government are carefully drafted and flexible, acting as strong incentives for Vietnamese fishermen," Sun said.