The influence of low-frequency laser emission on phyto- and zooplankton productivity properties

Abstract

We studied the possibility of using low frequency laser emission to improve production properties of feed hydrobionts, in particular microalgae Desmodesmus armatus and Daphnia magna, which are highly applied in aquaculture. It was shown that low-frequency laser emission with the wavelength 650 nm has a positive influence on production properties of both phyto- and zooplankton. In 24 hours the biomass of irradiated D. armatus was 25% larger than non-irradiated one. Meanwhile, application λ 420 and 530 nm did not show credible accumulation of microalgae biomass. If it comes to daphnia, positive dynamic in population density enlarging was observed only since 5-7th day of cultivation, depending on emission exposition. Differences in low-frequency laser emission with λ 420 and 530 efficacy on D. magna production properties were observed while using different exposition. Thus, maximal culture density was observed when λ 420 nm for 90 s and λ 650 nm for 60 s were applied. Longer irradiation with red laser did not have positive effect. It was established that in daphnia tissues, which were influenced by λ 420 nm laser emission, TBA-active products were accumulating more. Meanwhile, for daphnias, which were irradiated with red laser, TBA amount was not different from the control group one. Catalase activity increased while applying λ 650 nm laser emission. On the other hand, λ 420 nm did not cause credible increasing of catalase activity in comparison with control group. Taking received results about photobiological effects of low-frequency laser emission on D. armatus and D. magna into consideration, both biomasses enlargement during co-cultivation can be obtained if wavelength 650 nm is used.