TWO local universities announced yesterday that they have developed products to make fish safer for eating.

Both products have been approved by the Ministry of Agriculture as agricultural veterinary medicines.

A group led by Professor Yang Xianle from Shanghai Ocean University has developed the world’s first special alternative medicine to replace malachite green for curing saprolegniasis, which can infect more than 100 kinds of fish and fish eggs in China and cause huge economic loss.

Malachite green, once a popular treatment, has been banned in China since 2002 as it can be poisonous to humans.

“Though malachite green has been banned for 15 years and the government has been launching special campaigns every year to crack down on its illegal use, some aquatic farmers still take the risk to use it to prevent saprolegniasis,” said Yang. “The reason farmers did so is that malachite green is cheap and effective while there was no good alternative medicine,” he added.

The university cooperated with the Changsha Besat Biotechnology Institute and selected more than 1,000 potentially useful materials out of 10,000.

They chose metalaxyl and developed a powder that has had no safety problems in tests since being tested in 2008. It was also proved to be successful in preventing and curing the disease, reducing more than 430 million yuan (US$62.5 million) of direct economic losses and 540 million yuan of indirect losses caused by saprolegniasis, said Yang.

The powder has also passed several rounds of reviews in the past three years by more than 20 industrial experts before gaining the approval from the ministry.

Another team led by Professor Zhang Yuanxing at East China University of Science and Technology has produced a kind of live vaccine for Edwardsiella tarda, a disease that can be transmitted to humans and can infect fish.

The “EIBAV1” vaccine is the first officially registered live vaccine for mariculture animals in China and the world’s first fish vaccine against Edwardsiella tarda approved by government, according to the university.

The vaccine has been put into production and will cover about half of the turbot breeding bases in China.