| Krill plays a very important role in Antarctic marine ecology.As a key link in Antarctic marine ecosystem,the composition of Antarctic marine food web also shows that krill plays a decisive role.In order to study the spatial distribution characteristics of krill / krill swarm and its ecological impact,this study was carried out from two aspects.From one hand,the study aimed to analyze the interaction between krill and the spatial distribution under environmental factors,the other hand is to analyze the spatial distribution of krill from the ecological environment and the effect of krill fishery on the dependent species(Penguin).The environmental factors such as water temperature,photosynthetic effective radiance,depth,sea ice,chlorophyll,offshore distance,etc.were selected to study.The effects of ecological factors on krill mainly include three different penguins that fed on krill.The main innovation and highlight of this study is to introduce the spatial analysis model into the study of krill fishery,and to study the ecological effects of Antarctic krill fishery in the northern part of the Antarctic Peninsula and to obtain basic effective data.Over the years,many countries in the world have invested a certain amount of resources and efforts in the study of krill in Antarctica,which the Physiological analysis,food studies,reproduce and spatial distribution,etc.were included.The spatial analysis module has been applied to marine biology in recent years,but the research and application of this module to krill is rare in China.In addition,the potential impacts of krill fisheries on land-based predators are increasingly receiving global attention.The time span of this study is from 2010 to 2016.Based on the data collected during the implementation of the Antarctic Marine Living Resources Development and Utilization Project in China,and the environmental data obtained from the Global Environmental data website,the study was carried out on Temporal and spatial distribution of krill population and its ecological effects in the northern Antarctic Peninsula.The spatial analysis of Antarctic krill in the northern Antarctic Peninsula was carried out based on the geographical statistical model and the effects of environmental factors and ecological factors on the distribution of Antarctic krill were explored.To get knowledge of the effects under environmental factors on the distribution of krill,and whether the fisheries of krill have potential effects on the predation of the dependent species(Penguin).The results can provide scientific basis for further study on spatial distribution characteristics of krill and provide basic materials for the research and development of Antarctic marine ecosystem.Basic spatial data of krill collected by marine observers,number of krill stations,environmental factors collected(such as temperature,Depth data),as well as offshore distance data and depth data from secondary calculations,are the main types of data analyzed in this study.Environmental data for the study area,such as chlorophyll,photosynthetic active radiance,sea ice data and penguin Agglomeration point data,provided in conjunction with the environmental project website.Based on these data the study aimed in correlation analysis.And the relationship between environmental and ecological factors on spatial distribution of Antarctic krill was analyzed by using geo-statistical spatial analysis model.The main conclusions of this study include:(1)In the study area,the population with higher biomass is mainly distributed in the depth range of 175-450 m in the sea,and the temperature range is-1.1-0.9 ℃.(2)The value of CPUE will increase with the increase of temperature in the area where the catch per unit effort(CPUE)of krill fishing effort is higher and the optimum temperature range is higher.In the optimum depth range,the larger the distance from the krill population to the sea floor,the smaller the CPUE value.(3)The effect of photosynthetic available radiation on the distribution of krill was significantly different in season,especially in July,the distribution of krill tended to focus in the region with lower photosynthetic effective radiation.(4)When the sea ice coverage in winter is relatively high,the CPUE value of open water is the highest(May and June).(5)There was no significant correlation between the distance from krill to ice edge and CPUE.(6)The GWR model fitted the relationship between the spatial distribution of CPUE and environmental factors(krill population depth,offshore distance and temperature).The results showed that the surface temperature in the east-west of the southern Shetland Islands had a positive correlation with the spatial distribution of CPUE in the east-west direction.The spatial distribution of CPUE was negatively correlated with the depth of krill colony and the distance from shore,and there were inter-annual and regional differences.(7)The interaction between krill fishing and ecological environment was studied.The effect of krill fishery on the predation of penguins is not significant.In this study,the relationship between krill and environmental factors and the effect of krill fishing on Antarctic ecology were studied by combining spatial analysis with geo-statistical model.A comprehensive understanding of the spatial distribution of krill under the influence of environmental factors can be learned,as well as the impact of Chinese krill fishing on the ecological environment.The results of this study can provide basic information for further explaining the spatial distribution of krill population and its relationship with environmental factors and provide research ideas for exploring the correlation between krill fishery and krill dependent species. |
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