The Study Of Size-biomass Relationships Of Dominant Species Of Yellow Sea And East China Sea Throught Image Technology

In this paper, the influences of three common preservations on the size andbiomass of zooplankton were studied, and the size-biomass relationships of theJiaozhou Bay, Yellow Sea and East China Sea’s dominant species were established byimage analysis methods, using ZooScan.Results as following:5%formalin,-20℃froze and liquid nitrogen were several common zooplanktonpreservation methods, which had different influences on the size and biomass ofzooplankton, and the same preservation had different influences on the twozooplankton species, Calanus sinicus and Sagitta crassa. The body length changes ofthe above zooplankton preserved was the most stable and smallest, followed by thearea. The body length changes of zooplankton preserved in formaldehyde were thesmallest, while the area changes of zooplankton preserved in-20℃and liquidnitrogen were much smaller than in formaldehyde. Comparing to-20℃frozen fandliquid nitrogen, there were much small changes of zooplankton size when preservedin formalin. Formalin had the greatest influences on the biomass of zooplankton,followed by liquid nitrogen and-20℃frozen. The changes of size and biomass ofpreserved crustacean zooplankton, Calanus sinicus, were smaller than preservedgelatinous zooplankton, Sagitta crassa. The size-biomass relations of severaldominant species in Jiaozhou Bay, Yellow sea, and China East Sea, such as Calanussinicus, Sagitta crassa, Sagitta nagae，Themisto gracilipes, Euphausia pacifica,Euphausia nana, small jellyfish, and fish larvae, which were preserved by5%formalin and the size-biomass relations of fresh zooplankton species, such as Calanussinicus, Sagitta crassa, Themisto gracilipes. Body length, area and volume wereselected as size parameters, and fresh weight, wet weight, dry weight and carbonateand nitrogen content were used as biomass parameters. The results showed that therewere great correlations between the size and biomass of zooplankton. Thesize-biomass equations were significantly different between the fresh and preservedsample of the same species, and so were the equations between different sea areas. Then we found that the same species in different sea areas could be expressed by oneunified size-biomass equation. Euphausia pacifica and Euphausia nana could beexpressed unified by one equation, while Sagitta crassa, Sagitta nagae couldn’t.The differences between the size-biomass equations of one same zooplanktonspecies from different sea areas may have correlations with the environmental factors,such as temperature, salinity and foods. It provided theoretical basis for the fastevaluations of the biomass in large spatial and temporal scales, through theestablishments of size-biomass equations of dominant zooplankton species of thecoastal waters of China.