The ABC's of diatom identification using laser holography

Abstract

Biomonitoring systems designed to protect the integrity of aquatic ecosystems must satisfy complementary requirements if they are to be used in a successful management program. First, they must generate reliable information with respect to the current biological status of the ecosystem ; and second, they must be capable of reducing the lag time in the feedback of this information . This paper describes a biomonitoring system, currently being developed, that employs coherent optical spatial filtering techniques to rapidly identify diatoms and process species-abundance information . Preliminary results indicate that the optical problems associated with such a system can be overcome satisfactorily, although investigations are continuing into the problem of interfacing a microscope directly to the optical system . We envision that this system can eventually be employed in a management program along with chemical and physical data to obtain full beneficial use of the ecosystem without damage .

Label-free imaging and analysis of subcellular parts of a living diatom cylindrotheca sp. using optical diffraction tomography

“…Diatoms are major photosynthetic planktons that produce 20% of primary products on the earth. Previously, the shape of diatoms was measured using holographic microscopy [37][38][39]. However, the spatial resolution had been mostly limited.…”

The biospheric life support system: a unifying concept for ecotoxicologists and ecologists

“…Colonization rates of aquatic insect larvae are, especially on artificial substrates, affected substantially by drift, which, in turn, is affected by a number of other factors such as darkness and stream flow. For computer-interfaced monitoring systems (e.g., Cairns et al, 1977b;Cairns and Gruber, 1980), establishing response variability even for individual organisms is relatively easy (Gruber and Cairns, 1981). Robust statistical analysis can document variability at different periods of the day or other cyclic variations and chemical/physical attributes measured simultaneously and amenable to computer interfacing Almeida et al, 1978).…”