Investigation on the Chlorophyll-<em>a</em> Content of Phytoplankton in the Sea of Azov and the Don River by the Fluorescence Method

Results of in situ fluorescence investigations on chlorophyll-a (chl-a) of phytoplankton in the Sea of Azov (May to June 2018) and in the Don River estuary (September to November 2019) are presented. Continuous data series of chl-a fluorescence were obtained with flow-through fluorometers. Discrete reference measurements of chl-a concentration and phytoplankton biomass were performed by standard methods for the sake of comparison and eventual corrections. The fluorescence intensity values measured in a lateral surface salinity gradient of the Sea of Azov were found correlating with the obtained data on the chl-a concentration (R2 = 0.88, n = 27) and phytoplankton biomass (R2 = 0.90, n = 11). Instead, there was a weak correlation (R2 = 0.40, n = 33) between the fluorescence and phytoplankton biomass found in the estuary. This disparity in correlations was explained by the difference in conditions during measurements, which affected the fluorescence. There were no significant changes in both temperature and coenotic composition of phytoplankton in the course of the marine expedition. The measurements on the river covered a period characterized by the seasonal variations in the phytoplankton composition and by noticeable temperature fluctuations

Identification of semiaquatic avifauna species in shallow waters of the Don River delta using an autonomous remote-controlled midget floating craft

A survey method for identifying avifauna in shallow areas of the Don River delta has been developed and tested using a prototype of an autonomous remote-controlled and self-propelled floating craft equipped with technical means for optical-visual observation and video filming (hereafter referred as the complex). The complex is remote-controlled by an operator. The methodology of the work included designing the complex and testing it in open water bodies, reconnaissance of the shallow water bodies in the Don River delta where the complex might navigate, the approbation of the panoramic video recording of birds, and processing of the recorded video for identification of the species. The complex is able to reliably collect visual information on the move as well as being stationed at points for bird observation. Thanks to the test missions of the complex, the selected shallow areas of the Don River delta were explored for the first time and reviewed by panoramic video recording. The 16 birds were captured in the footage, and 7 out of them were reliably identified. The panoramic video records can be also used for educational purposes. The developed complex has a relatively low manufacturing cost and can be assembled in a university lab too