Detection Of Parameter Of Anchovy School And Analysis Of Environmental Factors Influence

In the biosphere,including the small microbes and the large mammals,the aggregation is a very common pattern.Most of the fish have aggregation behavior.The aggregation is based on physiological requirements and needs in life.Different fish have different type of aggregation,also related to the size of the aggregation and the species.The school characteristics of fish are important parameters that reflect their population dynamics and their resource status.As a resource developer and protector,the issue we concerned is those: why do fish school? How much is the school characteristics of fish? Where is the school? What are the environmental conditions required for the fish aggregation? This paper studied the characteristics of anchovy shoal and the relationship of shoal distribution and environment factors,based on the biology,acoustics and environmental factors,which was collected in survey of fishery resources in the Yellow Sea in August 2014 and 2016.In the first chapter,the status quo of fish aggregation were reviewed briefly.In the second chapter,the introduction is showed of the studies of anchovy.In the third chapter,the aggregation scale of anchovy was studied.The fourth chapter mainly studies the relationship between the distribution of anchovy and environmental factors.The main research results are as follows:1.The distribution of anchovy is mainly composed of patchy high density clusters(type ?),continuous stripe distribution(type ?)and scattered distribution(type ?).type ? is a typical aggregation echogram of anchovy.At the same time,there were vertical migration of anchovy between day and night.During the daytime,anchovy gather at the near and bottom of the seabed.2.The schooling length(type ?)is mainly concentrated in the range of 1m to 50m;the thickness is mainly concentrated in the range of 0.25 m to 10m;the cross-sectional area of the schooling is mainly concentrated from 1m~2 to 200m~2.The biomass density of the anchovy schooling is generally less than 200 g / m~2,and the anchovy schooling is mainly concentrated in the water layer with depth of 30 m to 50 m.3.It was found that the Yellow Sea cold water mass(YSCWM)determines the distribution of anchovy schooling and schooling always under the thermocline.4.In the two surveys,there were more than 80% of the anchovy congregates round the water in which the temperature is in the range of 6 ?-29.2 ?.And the salinity ranges of the anchovy cluster were 30.2-33 and 31.5-33.2.In August 2014,over 75% of the anchovy fish were concentrated in the salinity of 31 to 32 of the waters;the survey results of August 2016 show that 80% of the anchovies are concentrated in the salinity range of 32-33 of the waters.The environmental factors have a great impact on the distribution of anchovy schooling and the progress of fish cluster behavior research.