Como os microplásticos afetam o fitoplâncton marinho e a produtividade primária dos oceanos? Uma revisão sistemática

Abstract

Microplastics are a type of solid waste not soluble in water and named after their size smaller than 5 millimeters and larger than 1 micrometer. They can reach the environment in two ways: being formed from the degradation of macroplastics or released as small particles. Because of their size, microplastics directly affect small animals that can ingest these fragments, inserting them into the trophic chain. As for phytoplankton organisms, this material can act negatively, as it releases toxic substances into the water that can cause negative impacts on them. Therefore, carrying out a systematic review of the literature on this subject will provide a direction for where new or more studies need to be carried out and what is being researched on the subject, in addition to bringing together in a single document several literary sources on the subject. In order to carry out the systematic review work, some steps were necessary, being (1) establishing the title question, (2) defining some keywords to compose the search term for the identification of the works, (3) determining a protocol with questions that will direct research, such as: what is the effect of microplastics on oceanic primary productivity?; What is the main effect of microplastics on phytoplankton?; (4) search for works that are related to the topic researched in specific databases and curate with regard to repetition of the same that may be present in different search platforms; and (5) reading the works and extracting the data in order to analyze them through graphs, tables and figures, trying to answer the proposed questions. Thus, from this systematic analysis of the literature, it was possible to observe that microplastics can physically or chemically affect phytoplankton in a negative way, inhibiting growth, increasing mortality, among others, in addition to being harmful to primary productivity, as it ends up reducing it. In addition, it was possible to assess the gaps to be filled in the subject with regard to physiological effects, observe trends in the location of studies and point out new advances that must be made, in addition to the main vehicles for disseminating knowledge and if there are possible directions new ones that have not yet been studied in order to target the lines of knowledge. Considering the role of phytoplankton for global primary productivity and in counteracting greenhouse gasses, this work contributes to the advances in the Decade of Ocean Science for Sustainable Development with a focus on goal 14 of 2030 Agenda, Life below water. Keywords: plastic pollution, literature review, primary production.