Classification, Grading And Risk Assessment System Of Harmful Algal Blooms In Coastal China

In order to facilitate the data statistics and management of HABs disaster as well as uniform its information publication, a system for early warning of HABs and its hazard classification and grading were established to protect mariculture and public health in the present study by combining historical data and state-of-arts HABs status in Chinese coast The results of analysis revealed that HABs in China can be divided into four types based on the characteristics of HABs causative species and the effects of HABs on the human health and mariculture as follows: toxic species, fish-killed species, harmful species and unharmful species. In addition, accounting for the large differences in sizes, HABs can be divided into three grades of large (more than 1000km~2), middle (between 1000km~2 to 100km~2) and small (less than 100km~2). Thus, HABs occurring in Chinese coast can be clarified as 12 kinds and indicated by different colors and signs to facilitate publication by media. Further, the purposes of mitigating HABs hazard and protecting human health can be achieved by establishing the early warning system and emergency management measure for these different kinds of HABs.Meanwhile, the characteristics of classification, grading, temporal and spatial distribution, species and growing trend of all kinds of HABs were revealed by analyzing the historical data including the time, station, size and species of HABs occurrences in China twenty years ago. The frequencies and areas of HABs occurring in Chinese coast increased year after year. And the small grading and harmful species HABs were in majority. Eastern Sea was the largest area of HABs occurrence. The toxic and fish-killed species HABs occurred most frequently in Southern Sea. The peak period was from May to September every year. According to the characteristics of HABs, the hazard index of HABs disaster loss was calculated through four factors: classification, grading, direct economical loss and the number of death. The hazard index was divided into â…  - â…¤ degrees, which was supplied a gap in HABs disaster researches in China.At last, the hazard loss of HABs can be divided into four basic categories by...