Abstract:

In order to scientifically prevent the overwintering syndrome of freshwater fish and reduce the risk of disease outbreaks, this study, based on recent surveys of disease occurrence and data collection, deeply analyzed the meteorological background differences in the occurrence of overwintering syndrome diseases and established a meteorological assessment method for the onset of freshwater fish wintering syndrome. By statistically analyzing key meteorological elements, such as the first day when the temperature stably passes 12℃, the temperature before the cooling process, the time of cooling process occurrence, the cooling amplitude and accompanying precipitation amount, rainy days, etc., we identified the meteorological factors affecting fish overwintering syndrome. The study found that in addition to cooling and precipitation, the meteorological conditions before cooling were also important factors affecting the degree of fish disease occurrence. Based on this, we constructed a warming trap index based on risk trap theory and a precipitation index that comprehensively considers rainfall and rainy days, and developed a comprehensive meteorological index for fish overwintering syndrome. The results show that this comprehensive meteorological index can accurately reflect the timing and degree of disease occurrence, which is highly consistent with the actual disease situation. In addition, the study also determined the cumulative comprehensive meteorological index thresholds for different disease grades. This assessment method provides a scientific basis for meteorological monitoring and forecasting of freshwater fish overwintering syndrome.

Key words: freshwater fish, overwintering syndrome, evaluation method, meteorological influencing factors, meteorological index, meteorological assessment method, risk trap theory, warming trap index, precipitation index, comprehensive meteorological index