Spatial And Temporal Distribution Of Fenneropenaeus Chinensis Resources And Their Relationship With Environment In Southern Shandong Peninsula

Fenneropenaeus chinensis,as a large benthic shrimp,is an important species for proliferation and release in Shandong Province,and used to be the main fishing object of drift nets and bottom trawls in the Yellow Sea and Bohai Sea.Due to the influence of overfishing and frequent red tides,as well as the serious shortage of spawning prawn resources,weak protection measures for larvae and lax management of sea areas,the replenishment of prawn resources in China is seriously insufficient,and the catch amount has been at a low level for a long time.For this reason,the proliferation and release of F.chinensis has been carried out every year in Shandong province since 1984 except 1987.In this paper,F.chinensis was taken as the research object,and the variation law of F.chinensis resources in southern Shandong Peninsula was analyzed by using the special survey data of the southern Shandong Peninsula from 2010 to 2020 and the Statistical yearbook of Chinese fishery.The spatial distribution of F.chinensis resources and its relationship with environmental factors were discussed.It provides scientific reference for future breeding and release and sustainable development of fishery,and provides a new idea for investigation and study of other breeding and release species.The main results are as follows:1.From 1984 to 2020,A total of 28.428 billion prawns were released and 39700 tons of prawns were captured in the southern waters of Shandong Peninsula.The average annual catch of F.chinensis from 1984 to 2020 is 1074.8 t,and the average catch of F.chinensis from 2014 to 2020 is only 334.23 t,which is significantly low.There was a very significant positive correlation between the release quantity of F.chinensis and the fishing yield in the southern sea area of Shandong Peninsula from 1984 to 2013(P < 0.01).There is no correlation between the number of proliferation and release of Penaeus chinensis from 2014 to 2019 and the yield,which is caused by the failure of proliferation and release effect to reach the expected value in recent years,red tide disasters and frequent oil spills.2.The data of 418 trawl surveys on the resources of F.chinensis after proliferation and release in the southern waters of Shandong Peninsula from 2010 to 2020 were used to analyze.A total of 7314.83 g of F.chinensis was captured during the period.The distribution of F.chinensis resource density in the coastal waters of the southern Shandong Peninsula is significantly different in time and space.The interannual resource density ranges from 8.69± 2.95 to 35.53 ± 8.60 g / h,showing great randomness in space.The occurrence frequency of Penaeus chinensis(the proportion of stations where F.chinensis appeared in the survey to the total survey sites)remains at a low level,with an average occurrence frequency of30.86%,The frequency of occurrence of F.chinensis in different years was significantly different(P < 0.01).3.In order to study the spatial and temporal distribution characteristics of F.chinensis resources in the coastal waters of the southern Shandong Peninsula,based on the bottom trawl survey data from 2010 to 2020 in August,global Moran index,hot spot analysis and distribution center method were used.The CPUE distribution centers and spatial autocorrelation of F.chinensis resources in coastal waters of the southern Shandong Peninsula were compared and analyzed.The results showed that the distribution center of F.chinensis was concentrated near the 25 m isobath line,and showed a trend of east-west direction and north-south direction in latitude and longitude.The global spatial autocorrelation analysis shows that,except for 2020,there is a weak global spatial autocorrelation,and all the other years show a significant random distribution pattern.The distribution of cold spots and hot spots of F.chinensis showed certain randomness,and the local spatial autocorrelation was low.The results of this study are helpful to clarify the distribution of F.chinensis resources in the southern waters of shandong Peninsula,and provide reference for the future investigation and proliferation and release of F.chinensis resources.4.Using the marine environment data and catch data of various stations obtained during the survey of F.chinensis resources in the southern sea area of Shandong Peninsula from 2010 to 2020,and using ANOVA one-way ANOVA and biological importance index analysis,the results show that the resource density of F.chinensis has different degrees of correlation with water depth,fishing boat towing speed and ocean temperature.The resources of F.chinensis will be affected by competitors and predators with high IRI index,which is also illustrated by the study of biological importance index.Trachypenaeus curvirostris and Metapenaeopsis dalei will compete with F.chinensis,and Gobiidae and Lateolabrax japonicus will prey on the larvae of F.chinensis.The high IRI index of such biological populations will affect the resources and distribution of Penaeus chinensis.