Evaluation of the Toxicity of Microplastics in the Supralittoral of the Barents Sea using Test Objects of Different Trophic Levels

The influence of different types of microplastics (MP) and ash after burning a mixture of macroplastics selected in the supralittoral of the Barents Sea on the development of traditional test objects of the culture of the green microalgae Scenedesmus quadricauda and the culture of cladocerans Daphnia magna in chronic experiments was studied. In terms of inhibition of algal growth at a concentration of 3 mg/L MP, the PU sample showed the highest toxicity, followed by HDPE (white), HDPE (red) and contact EPS in descending order of toxicity. PP was non-toxic. Ash in the concentration range of 0.01-1000 mg/L did not significantly inhibit the growth of Scenedesmus quadricauda. For Daphnia magna a more expressed decrease in the average linear size was noted with the addition of intact EPS, and the stimulation of fertility was significantly higher in the presence of contact EPS. When comparing the effect of intact and contact PU on D. magna, the death of all individuals under the influence of intact PU was found, while adding PU, survival remained at the control level. MP particles and ash affect the trophic activity of daphnia when fed with chlorella, but this effect does not lead to changes in fertility and growth during long-term observation.