SEASONAL VARIATIONS IN ABUNDANCE AND SIZE STRUCTURE OF COPEPODS IN THE COASTAL WATERS OF SHANDONG
Marine copepods play a crucial role as essential bait for economically valuable fish species,which directly influence the output quantity and quality of both fisheries resources and economically farmed organisms.However,current research on copepods biomass and spatial distribution focuses on mainly typical bays such as Jiaozhou Bay,Laizhou Bay,and Rongcheng Bay,with a lack of comprehensive studies on copepods in the overall coastal waters of Shandong Province.To investigate the seasonal dynamics of copepod abundance and spatial distribution in the coastal waters of Shandong Province,we utilized ZooScan image analysis on plankton samples collected in four research cruises conducted in 2022～2023.The seasonal variations in copepod abundance,volume biomass,size composition,and distribution patterns were explored and the relationships between these factors and environmental variables were examined.The normalized biovolume size spectra(NBSS)were constructed to characterize the relative size distribution and energy transfer efficiency of copepod.Results indicate that copepod abundance in the coastal waters was higher in spring(May)and summer(August)than in winter(February and December),and high abundance was concentrated in mainly the Bohai Sea area.Spearman correlation analysis revealed a significant negative correlation between copepod abundance in spring and surface seawater salinity,while in summer,a significant negative correlation with surface seawater temperature was observed.Moreover,the NBSS slope of copepods in spring was the shallowest and the intercept was the largest,indicating that the productivity level and energy transfer efficiency of copepods to higher trophic levels were higher in spring than in summer and winter.The copepod NBSS intercepts in summer were significantly positively correlated with surface seawater salinity.The dynamic changes of copepod abundance in this area can provide a theoretical basis for fisheries resource production.
万方数据
维普
