Effects of plastic pollution and ocean warming on Phaeodactylum tricornutum and Nitokra spinipes
De Witte, Y. (2023). Effects of plastic pollution and ocean warming on Phaeodactylum tricornutum and Nitokra spinipes
. MSc Thesis. UGent. Faculteit Bio-ingenieurswetenschappen: Gent. 66 pp.
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Document type: Dissertation
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| Abstract |
Human activity has led to two major environmental stressors: plastic pollution and climate change. Plastics, renowned for their convenience and versatility, are being increasingly produced globally. High production rates, low recycling rates, extensive littering, and persistence of plastic materials result in accumulating, omnipresent plastic debris with various size categories including microplastics (1 μm - 5 mm). Alongside the physical presence of microplastics, the release of monomers and additives from plastics into the environment, known as leachates, adds to the complexity of the issue. Both (micro)plastic particles and leachates are of concern. As climate change progresses due to carbon emissions from human activities, ocean warming has emerged as a defining consequence. This second stressor can affect marine organisms at different trophic levels and can alter community compositions. Within this context, the objective of this study was to assess the effects of plastic leachates on algal growth rates and to explore the combined effects of plastic leachates and ocean warming on copepod mobility. The research began by investigating the ecotoxicity of plastic leachates on Phaeodactylum tricornutum, a diatom responsible for oceanic primary production. The results demonstrated growth inhibition caused by PVC leachates and seawater-aged PLA leachates, emphasizing the influence of material weathering on leachates’ toxicity. Furthermore, the study delved into the interaction between temperature and plastic leachate toxicity. Surprisingly, despite a 3 °C temperature increase, the toxic effects of PVC leachates on adult Nitokra spinipes, a harpacticoid copepod, did not significantly intensify. This outcome underscores the complexity of multiple stressor interactions. In conclusion, this comprehensive study provides insights to unveil the intricate connections between plastic pollution, ocean warming, and aquatic organisms. By investigating the toxicity of plastic leachates and their interplay with temperature stress, the research contributes to the understanding of potential ecological consequences. Ultimately, this work may guide informed decision-making for sustainable plastic usage and marine ecosystem preservation. |
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