한국 연안에서 발생하는 Cochlodinium polykrikoides 적조과 비 적조 해역의 광학적 구별

Abstract

Harmful Cochlodinium polykrikoides blooms have occurred and caused large damages to the fishery industry in the coastal waters of Korean peninsula since late 1980s. In order to effectively detect and monitor the spatial and temporal distributions of widespread C. polykrikoides blooms, in-situ radiometric measurements and/or satellite remote sensing can be used. In this study, we estimated the apparent optical properties (AOPs) from the inherent optical properties (IOPs) of C. polykrikoides blooms using forward calculation and exploited distinctive optical characteristics to discriminate C. polykrikoides blooms from non-harmful blooms in the visible wavelength. We developed the optical discrimination method where Rrs band ratios (R1: Rrs(555)/Rrs(531), R2: Rrs(488)/Rrs(443)) were simulated using the Hydrolight software. Even under optically complex water conditions, C. polykrikoides blooms show clear differences in simulated Rrs spectra due to increased effect of C. polykrikoides absorption properties in the bloom waters where chlorophyll-a concentrations were high (≥ 15 μg l-1). In-situ Rrs(λ) was comparable within the results of simulation. Consequently, the optical discrimination of C. polykrikoides blooms from non-bloom is plausible in Rrs band ratios space, both simulated and measured in-situ data.utions of widespread C. polykrikoides blooms, in-situ radiometric measurements and/or satellite remote sensing can be used. In this study, we estimated the apparent optical properties (AOPs) from the inherent optical properties (IOPs) of C. polykrikoides blooms using forward calculation and exploited distinctive optical characteristics to discriminate C. polykrikoides blooms from non-harmful blooms in the visible wavelength. We developed the optical discrimination method where Rrs band ratios (R1: Rrs(555)/Rrs(531), R2: Rrs(488)/Rrs(443)) were simulated using the Hydrolight software. Even under optically complex water conditions, C. polykrikoides blooms show clear differences in simulated Rrs spectra due to increased effect of C. polykrikoides absorption properties in the bloom waters where chlorophyll-a concentrations were high (≥ 15 μg l-1). In-situ Rrs(λ) was comparable within the results of simulation. Consequently, the optical discrimination of C. polykrikoides blooms from non-bloom is plausible in Rrs band ratios space, both simulated and measured in-situ data.