Study On Microbial Enrichment Of Shellfish And Monitoring Location Method In Aquaculture Area

In order to explore the microbial enrichment and factors affecting microbial enrichment of different mari culture shellfish,current status of shellfish microbial hygiene were investigated in Yueqing bay and Shengsi sea area.We also analysised the location monitoring method of harbour-type intertidal shellfish in aquaculture areas.The concrete research contents were as follows:(1)Validation and comparison of microbial enrichment of different shellfish varieties in the same cultivation areas.(2)Study on the main factors afecting microbial enrichment and investigating on the enrichment law of shellfish in growing environment.(3)Investigation on increase and decrease regularity of shellfish in cultivation areas.(4)Parabolic stationing method application to intertidal shellfish and growing waters microbiological monitoring.(5)Health status monitoring and evaluation of cultured shellfish along the Zhejiang coast.The experimental results show the following seven points.(1)The numerical value of Escherichia coli was relatively higher than that of Meretrix meretrix and Tegillarca granosa.In addition?there was no significant difference between Meretrix meretrix and Tegillarca granosa,and there was no significant difference in aerobic plate count of the three varieties.(2)The change of water quality has affected the shellfish-enriched Escherichia coli to some extent,but the change of microorganisms in sediment has no direct effect in shellfish.(3)The numerical value of Escherichia coli and aerobic plate count was higher in Tegillarca granosa and Sinonovacula constricta when sunny after continuous rainfall.(4)The results indicated that numbers of Escherichia coli and aerobic colony count in S.constricta flesh showed approximate’parabola’distribution across the whole shellfish bed.Numbers of faecal coliformin seawater samples were significantly higher in the top of the bay,Numbers of Escherichia coli and aerobic colony count were significantly higher in the top of the bay,and lower in the lower half of the bay.There was a positive correlation between the value of Escherichia coli and aerobic colony count.(5)There was also a positive correlation between the value of Escherichia coli in S.constricta and faecal coliform in seawater samples.(6)The faecal coliform in seawater samples was higher located in the edge of the bay than the center in contrast to three sampling sites on the same latitude.(7)It was obvious that the hygienic situation in aquaculture areas along the Zhejiang coast in the Yueqing bay and Shengsi were better than before.The proportion of class ’A’of Escherichia coli in Shengsi was much higher than that in Yueqing bay.It shows that the environment of shellfish culture area in Shengsi was better than that of Yueqing bay.