| In recent years,with the intensification of climate change and human in the northern part of the Antarctic Peninsula,it will pose a threat to the organisms living in it.As a key species in the Antarctic food chain(web),Antarctic krill(Euphausia superba)is an important food source for a variety of predators(such as whales,seals,penguins and seabirds).Trace elements are good indicators for marine organisms to normalize physiological activities or study the impact of environmental changes.Therefore,this study takes Antarctic krill as the research object,uses graphite furnace atomic absorption spectrophotometry or atomic absorption spectrophotometry flame to study the essential elements,i.e.,copper[Cu] and zinc[Zn],and non-essential elements,i.e.,cadmium[Cd]and lead[Pb],and analyzes the content and temporal and spatial differences of the above elements in Antarctic krill in the north of Antarctic Peninsula,Combined with the measurement of trace element content in relevant sea waters,the enrichment degree of trace elements in water by Antarctic krill was discussed.In order to understand the mechanism of trace element accumulation of Antarctic krill and its importance in biochemical cycle,and provide basic reference for better development and management of krill fishery.The main results of this study are as follows:1)The enrichment coefficients of trace elements Cu,Cd and Pb in water by krill in the north of Antarctic Peninsula are 64.21,3.10 and 1.74 respectively.The enrichment degree of trace elements in water by krill in Antarctica is Cu > Cd > Pb.2)The enrichment factor of krill to trace elements in water is not only affected by the concentration of trace elements in water and the demand of krill for trace elements,but also affected by the terrain,sediment,hydrology(such as p H,salinity,etc.)and other environmental factors of the study area.3)The trend of trace element concentration in krill in the north of Antarctic Peninsula is mostly Cu > Zn > Pb > Cd,and the trend of trace element concentration in a small number of krill is Zn > Cu > Pb > Cd.It is speculated that it may be due to the high abundance of phytoplankton in the environment.The concentration of essential elements in krill is two orders of magnitude higher than that of non-essential elements,which is caused by the physiological function of elements in krill.4)There are obvious regional differences in trace elements in krill in the north of Antarctic Peninsula.There is no regional difference in copper.There are differences in zinc between the central basin of Bransfield Strait(CB)and the northern shelf of South Shetland Islands(NS),cadmium between CB and NS and between ns and the western basin of Bransfield Strait(WB),and lead between CB and WB and between ns and WB.The regional difference is due to the change of physical and chemical properties in the study area due to the influence of different water masses.5)In 2018,there were significant annual differences in trace elements in krill.There are significant differences in copper between summer and autumn and autumn and winter.There are significant differences in cadmium content in krill between summer and autumn,summer and winter,autumn and winter,while the seasonal differences in lead content occur between summer and winter,autumn and winter,while the content of zinc is the same in the three seasons,and there is no difference.It is inferred that the annual difference is mainly caused by the feeding objects of krill in different seasons and seasonal sea ice.6)There are significant interannual differences in trace elements in krill from 2016 to 2020.The difference is mainly caused by copper and lead.The differences of these elements are caused by the differences in krill in 2016,which belongs to a year with large climate change.This difference may lead to the differences in krill elements in 2016.7)There are interactions among trace elements in krill,including additive,antagonistic and synergistic effects.In krill,there are interactions between zinc and cadmium,zinc and lead,lead and cadmium.These interactions also affect the content of trace elements in krill. |
