A spokesman for the working group said a red tide formed by prorocentrum dentatum and prorocentrum minimum was observed along shing mun river by staff of the environmental protection department last friday ( january 7 ) and the red tide began to dissipate on january 13 该处高级兽医师薛汉宗今日（星期四）在介绍这套新制度时说：新措施能有效地追查牛只的来源，进一步保障市民健康。
