Removal effects on harmful algal bloom species of eco-friendly algicidal substance ‘Green TD49’

Abstract

Since the 1960s, the frequency of harmful algal bloom (HAB) events has gradually increased, and it has been causing serious ecological and economic problems in Korea. Particularly, massive blooms of Cochlodinium polykrikoides caused and severely increased economic losses of fishery industries due to fish mortality in the coastal area, and blooms of Microcystis have been causing serious water quality problems in fresh water system. Many physical, chemical, and biological algaecidal techniques have been developed to combat HAB, of which the physical and chemical techniques employed for killing harmful algae are more stable than those of biological controls e.g. algae-cidal bacteria, ciliates, and zooplankton. A novel algicidal naphthoquinone derivate substance, ‘Green TD49’ was developed, and tested its algicidal activity on HAB species, C. polykrikoides and Microcystis, and biological toxicity using Artemia and natural zooplankton. In screening test using C. polykrikoides culture, the suitable concentration of Green TD49 was 1 ppm for field application . The active chlorophyll a. and cell abundance of C. polykrikoides were dramatically decreased after three hours of Green TD49 inoculation. In microcosm test (20 liter), cell density of bloomed Microcystis was rapidly decreased after one day of Green TD49 inoculation. Developed algaecidal substance has had a remarkable HAB removal effect, moreover it showed non-toxic erely increased economic losses of fishery industries due to fish mortality in the coastal area, and blooms of Microcystis have been causing serious water quality problems in fresh water system. Many physical, chemical, and biological algaecidal techniques have been developed to combat HAB, of which the physical and chemical techniques employed for killing harmful algae are more stable than those of biological controls e.g. algae-cidal bacteria, ciliates, and zooplankton. A novel algicidal naphthoquinone derivate substance, ‘Green TD49’ was developed, and tested its algicidal activity on HAB species, C. polykrikoides and Microcystis, and biological toxicity using Artemia and natural zooplankton. In screening test using C. polykrikoides culture, the suitable concentration of Green TD49 was 1 ppm for field application . The active chlorophyll a. and cell abundance of C. polykrikoides were dramatically decreased after three hours of Green TD49 inoculation. In microcosm test (20 liter), cell density of bloomed Microcystis was rapidly decreased after one day of Green TD49 inoculation. Developed algaecidal substance has had a remarkable HAB removal effect, moreover it showed non-toxic