Optical characterization of two cyanobacteria genera, Aphanizomenon and Microcystis, with hyperspectral microscopy

Barry H Rosen,David W Allen,E Terrence Slonecker,Emily C Paine,Nancy S Simon,Ronald G Resmini

doi:10.1117/1.jrs.12.036013

Abstract

Cyanobacterial blooms are a nuisance and a potential hazard in freshwater systems worldwide. Remote sensing has been used to detect cyanobacterial blooms, but few studies have distinguished among genera of cyanobacteria. Because some genera are more likely to be toxic than others, this is a useful distinction. Hyperspectral imaging reflectance microscopy was used to examine cyanobacteria from Upper Klamath Lake, Oregon, at high spatial and spectral resolution to determine if two species found commonly in the lake, Aphanizomenon flos-aquae and Microcystis aeruginosa, can be separated spectrally. Of the analytical methods applied, a spectral shape algorithm applied to the derivative was found to be most successful in classifying these species in microscope scenes. Further work is required to determine if the spectral characterization of cyanobacterial genera can be scaled up to remote sensing applications.

Highlights

IntroductionBlooms are exacerbated by high nutrient inputs and warm waters and have been appearing with increasing frequency in water bodies used for drinking water supply or recreation, a problem which will likely worsen as the climate warms.[1,2,3] Cyanobacterial blooms are a nuisance for their unsightly surface scums and the production of taste-and-odor compounds, and some strains of cyanobacteria produce toxins that are hazardous to human and animal health.[4] Toxic cyanobacterial harmful algal blooms, or cyanoHABs, are not immediately distinguishable from nontoxic nuisance blooms; laboratory analysis is required to identify the species present and test for toxins.[2] For large water bodies, collecting point samples is insufficient to quantify the true extent of the toxic algae, as blooms are often heterogeneous and dynamic.[5]
Cyanobacterial blooms in eutrophic inland waters are a worldwide concern
The success of the derivative spectral shape equations shows that the spectral differences are consistent across all the imagery collected from Upper Klamath Lake (UKL) samples in summer 2016

Summary

Introduction

Blooms are exacerbated by high nutrient inputs and warm waters and have been appearing with increasing frequency in water bodies used for drinking water supply or recreation, a problem which will likely worsen as the climate warms.[1,2,3] Cyanobacterial blooms are a nuisance for their unsightly surface scums and the production of taste-and-odor compounds, and some strains of cyanobacteria produce toxins that are hazardous to human and animal health.[4] Toxic cyanobacterial harmful algal blooms, or cyanoHABs, are not immediately distinguishable from nontoxic nuisance blooms; laboratory analysis is required to identify the species present and test for toxins.[2] For large water bodies, collecting point samples is insufficient to quantify the true extent of the toxic algae, as blooms are often heterogeneous and dynamic.[5].

Objectives

Results

Discussion

Conclusion