MULTISPECTRAL MEASUREMENTS OF THE PIGMENTAL PARAMETERS OF THE PHYTOPLANKTON IN AQUEOUS MEDIA

Abstract

The increase of the indirect measurement accuracy of phytoplankton pigment parameters in natural aquatic habitats is necessary for the solution of the problems of ecological monitoring of water objects, their ecotoxicological control as well as multiparametric control of water quality. Applying the technique of the mathematical modeling of light scattering in small angle approximation in multilayer nonuniform media, the direct problem of determination the spectral characteristics of natural aquatic habitats on changes of the pigment parameters of phytoplankton is solved. In the given research, the process of the in direct measurement of the phytoplankton pigment parameters in aquatic habitats by means of multispectral method is studied, the regression equations are obtained, enabling to determine the relation between the chlorophyll a and general chlorophyll, as well as the relation between the carotinoids and general chlorophyll.  For this purpose, the procedure of multiregression with step-by-step inclusion of the independent variables is used. The analysis of the methodical and instrumental errors of the phytoplankton pigment parameters measurements in aquatic habitats is performed, using in multispectral device of ecological measuring control light emitting diodes, laser diodes and monochromator as the radiation source. Optimal variants of the realization of the means of multispectral ecological control of pigment parameters of the phytoplankton in the aquatic habitats is chosen, depending on the cost of their realization and general measurement error. In the process of measurement the relation between the chlorophyll a and general chlorophyll of the phytoplankton in the aquatic habitat, the least general error of 0.381% was obtained for the 6-channel device of multispectral measuring control with the width of spectral range in each channel of 20 nm. In the process of measurement the relation between carotinoids and general chlorophyll of the phytoplankton in the aquatic habitat 5 channel device with the width of spectral range in each channel 20 nm was chosen to be an optimal variant of the device for multispectral ecological control, it enables to obtain general measurement error of  not more than 0.486%.