Since August 2006, Hong Kong authorities have been warning residents of malachite green, a synthetic dye used to treat fungal infections on fish eggs and considered dangerous for human health. They have been reporting that live freshwater fish from the mainland have tested positive for malachite green.
Guangdong, separated from Hong Kong by the Shenzhen River, is the biggest mainland fish marketer, shipping a total of 1,752.6 tons of live freshwater fish last month, but the negative report on freshwater fish is hurting the fish industry in Guangdong.
Hong Kong is traditionally the largest consumer of live fish raised in the province, accounting to three-fourths of Guangdong's sales. Its exports of live fresh-water fish to Hong Kong amounted to $62.28 million in 2006.
The Health, Welfare and Food Bureau of Hong Kong had issued a list of registered freshwater fish farms authorized for supplying fish. However, ongoing public concerns have affected sales.
While low levels of malachite green are not considered harmful to human health, Hong Kong consumers, who consider food safety as a high-profile issue, aren't taking any chances.