Video system for monitoring zooplankton and suspended particles

At present, the measurement of the vertical structure of the distribution of particulate matter is performed using labor-intensive methods using sampling with plankton nets or bathometers, followed by visual microscopic examination of samples in a laboratory. For real-time monitoring of water areas (ecological and fishery tasks), video recording of plankton and other particulate matter with real-time image transmission to the operator is relevant. Colored in situ images obtained from a ship using a probe on a carrying cable make it possible to quickly estimate the concentration of particles at the horizons, and visually select zoo and phytoplankton. An analysis of the currently existing equipment for recording plankton images is given, its shortcomings are indicated, and our own experience in the development and test results of the original video recording equipment created in this case is described. The design of a high-resolution submersible camera (2048x1436 pixels) with an original lighting system with rod lamps based on powerful white LEDs, an instantly recorded volume of 150 cubic centimeters, is described. Examples of registration of images of cultured freshwater daphnia in laboratory conditions are shown. The results of work with the camera in October 2019 at the Hydrobiological Station of A.N. Severtsov Institute of Ecology and Evolution (Lake Glubokoe, Ruzsky District of the Moscow Region) with obtaining color images of suspended matter to a depth of 30 m with simultaneous measurement of the temperature and concentration of oxygen dissolved in water are presented. By subsequent visual processing of the images obtained at different depths, an estimated profile of the distribution of zooplankton in depth was obtained. The result of research, laboratory and field tests was the creation of an operational monitoring video recording system that allows visual studies of plankton in situ; ways to improve the characteristics of the system are shown