Underwater Holographic Sensor for Plankton Studies In Situ including Accompanying Measurements.

Victor Dyomin,Igor Polovtsev,Alexandra Davydova,Sergey Davydov,Nikolay Kirillov,Alexey Olshukov

doi:10.3390/s21144863

Abstract

The paper presents an underwater holographic sensor to study marine particles—a miniDHC digital holographic camera, which may be used as part of a hydrobiological probe for accompanying (background) measurements. The results of field measurements of plankton are given and interpreted, their verification is performed. Errors of measurements and classification of plankton particles are estimated. MiniDHC allows measurement of the following set of background data, which is confirmed by field tests: plankton concentration, average size and size dispersion of individuals, particle size distribution, including on major taxa, as well as water turbidity and suspension statistics. Version of constructing measuring systems based on modern carriers of operational oceanography for the purpose of ecological diagnostics of the world ocean using autochthonous plankton are discussed. The results of field measurements of plankton using miniDHC as part of a hydrobiological probe are presented and interpreted, and their verification is carried out. The results of comparing the data on the concentration of individual taxa obtained using miniDHC with the data obtained by the traditional method using plankton catching with a net showed a difference of no more than 23%. The article also contains recommendations for expanding the potential of miniDHC, its purpose indicators, and improving metrological characteristics.

Highlights

Modern marine science draws huge attention to global measurements both for fundamental purposes—building models of global ecosystems, and for solving applied problems, especially in predicting the efficiency and consequences of economic activities
We propose using digital holography to study plankton
The field testing of the miniDHC showed that its capabilities correspond to the set of measurable background data required for biodiversity monitoring and ecosystem monitoring, such as:

Summary

Introduction

Modern marine science draws huge attention to global measurements both for fundamental purposes—building models of global ecosystems, and for solving applied problems, especially in predicting the efficiency and consequences of economic activities. This usually covers biological objects, primarily plankton [1], as the base of the global food chain and a natural bioindicator. Oil droplets may be present in water in case of small leaks, for example, in the waters of an oil platform, oil pipeline, gas bubbles in the gas pipeline area, etc These data are quite necessary for sustainable ecosystem observations in the water area of economic activity [2]

Methods

Results

Conclusion