Regression Between Biomass And Size Parameters In Zooplankton Based On ZooScan

Zooplankton plays an important role in marine ecosystem, and so does thebiomass in marine ecology reseach. A new system named ZooScan intergrated byzooplankton scanning, processing and automatic identification can obtain quantity,size and taxonomic information quickly. This study got regressions between length,area, biovolume scanned by ZooScan and wet weight, dry weight, Carbon andNitrogen content. Ande the results are shown as follows:1. Regressions of copepod, chaetognath, amphipoda and small shrimp have beenbuilt between wet weight and length, area and biovolume. Significant relationshipwere found between wet weight and size parameters (P<0.01). After comparingcorrelation coefficients (r), area fit wet weight best in copepod, chaetognath, andsmall shrimp, but length fit wet weight best in amphipoda. The regressions are:Copepod：lgWW=1.16lgA+2.53; Chaetognath：lgWW=1.56lgA+2.24Small shrimp：lgWW=1.02lgA+2.63; Amphipoda： lgWW=2.25lgL+2.242. Regressions between dry weight and length, area and biovolume have beentaken in Calanus. sinicus and Sagitta. crassa. Results show that there are significantrelationship (P<0.01) between dry weight and size parameters of C. sinicus. In thethree correlation coefficients (r) of these regressions, r of area-dry weight is thebiggest, which means area fits dry weight best in C. sinicus. The equation betweenlength and dry weight of S. crassa has no significance relationship, while area andbiovolume to dry weight have significance relationship (p<0.01). And r of area-dryweight is bigger than r of biovolume-dry weight showing area fits better.The equations of Area-dry weight of C. sinicus could be divided into two parts: Unmature: lgDW=1.44lgA+1.69Mature: lgDW=0.85lgA+2.08The dry weight of S. crassa could be estimated roughly by united datas:lgDW=1.54lgA+1.323. There are significance relationship (P<0.01) between the three parameters andCarbon content and Nitrogen content of C. sinicus and S. crassa. In our study, Carboncontent against dry weight of C. sinicus ranges from31.2%to44.5%and has anaverage of38.2%. And the Nitrogen content against dry weight ranges from8.1%to9.5%with an average of9.5%. Area fits Carbon content and Nitrogen content bestafter comparing r of the regressions. For S. crassa, the Carbon content against dryweight varies between6.0%and41.3%, the average is29.5%. The Nitrogen contentagainst dry weight ranges from3.2%to10.8%with an average of7.4%. Area andbiovolume have significance relationships (P<0.01) against Carbon and Nitrogencontent, but equations of Length-Carbon and Nitrogen content have no significancerelationship. And as expected, area fits Carbon content and Nitrogen content better.As dryweiht, the equations between Carbon and Nitrogen content and area couldbe divided into two parts:Mature: lgC=1.62lgL+1.31lgN=1.23lgA+0.86Unmature: lgN=1.61lgA+0.63lgC=1.72lgA+1.22And the Carbon and Nitrogen content of S. crassa could be estimated roughlyby:lgC=1.56lgA+0.76; lgN=1.71lgA+0.04Zooplankton biomass can be reliably estimated by image method based onZooScan. It would be an accurately and rapidly method for biomass research.