Water quality and cyanobacterial anatoxin-a concentration in Daechung reservoir = 대청호의 수질과 남조류 독소 Anatoxin-a 농도의 관계

Abstract

The current study was performed to elucidate the relationship between the anatoxin-a produced by cyanobacteria and aquatic environmental factors. Algal and water samples were collected from the Daechung Reservoir from June to November 2001. The physical factors of the water quality were measured in situ, while the biological and chemical factors were examined in the laboratory. The concentrations of anatoxin-a in the algal and water samples were analyzed by HPLG using a fluorescence detector and ranged from 0.61-8.68 ㎍/g dw in the algal samples and 0.01-0.08 ㎍/ℓ in the water samples. The suggested maximum concentration of anatoxin-a for safe drinking water is 1 ㎍/ℓ. The concentrations of anatoxin-a in the algal and water samples were highest in July. The relationships between the aquatic environmental factors and the anatoxin-a concentration were also analyzed to identify the crucial elements for toxin production. The anatoxin-a concentrations in the algal samples exhibited a high correlation with nitrate, the TN/TP ratio, TDN(P<0.05), and TPN/TPP ratio(P<0.01), whereas the anatoxin-a concentrations in the water samples were highly related to the water temperature, conductivity(P<0.01), pH, phycocyanin, and phycocyanin/chlorophyll a ratio(P<0.05).