title: Variations in the optical scattering properties of phytoplankton cultures.
abstract: The scattering and backscattering coefficients of 15 phytoplankton species were determined in the laboratory using the acs and BB9 instruments. The spectral variability of scattering properties was investigated and the homogenous sphere model based on Mie theory was also evaluated. The scattering efficiencies at 510 nm varied from 1.42 to 2.26, and the backscattering efficiencies varied from 0.003 to 0.020. The backscattering ratios at 510 nm varied from 0.17% to 0.97%, with a mean value of 0.58%. The scattering properties were influenced by algal cell size and cellular particulate organic carbon content rather than the chlorophyll a concentration. Comparison of the measured results to the values estimated using the homogenous sphere model showed that: (1) The model could well reproduce the spectral scattering coefficient with relative deviations of 5-39%, which indicates that cell shape and internal structure have no significant effects on predicting the scattering spectra; (2) Although the homogenous sphere model generally reflected the spectral trend of backscattering spectra for most species, it severely underestimated the backscattering coefficients by 1.4-48.6 folds at 510 nm. The deviations for Chaetoceros sp. and Microcystis aeruginosa were large and might be due to algal cell chain links and intracellular gas vacuoles, respectively.
authors.affiliation: State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. wenzhou@scsio.ac.cn
authors.forename: Wen
authors.initials: W
authors.lastname: Zhou
authors.forename: Guifen
authors.initials: G
authors.lastname: Wang
authors.forename: Zhaohua
authors.initials: Z
authors.lastname: Sun
authors.forename: Wenxi
authors.initials: W
authors.lastname: Cao
authors.forename: Zhantang
authors.initials: Z
authors.lastname: Xu
authors.forename: Shuibo
authors.initials: S
authors.lastname: Hu
authors.forename: Jun
authors.initials: J
authors.lastname: Zhao
mesh_terms: D000465:Algorithms; D002681:China; D002734:Chlorophyll; D000077194:Chlorophyll A; D004784:Environmental Monitoring / Q000379:methods*; D005618:Fresh Water / Q000737:chemistry*; D008027:Light; D008962:Models, Theoretical; D009791:Oceanography / Q000379:methods; D055095:Optics and Photonics; D010316:Particle Size; D052638:Particulate Matter; D010839:Phytoplankton / Q000737:chemistry* / Q000378:metabolism*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D014874:Water Pollutants, Chemical
chemical_list: D052638:Particulate Matter; D014874:Water Pollutants, Chemical; D002734:Chlorophyll; D000077194:Chlorophyll A