Distribuição e caracterização do macro e microplástico em ecossistemas costeiros

Abstract

Plastic pollution has become a threat to our planet in recent years. Due to its low cost, physical-chemical properties and durability, plastic has been widely used throughout society, becoming ubiquitous in our lives and in the most diverse ecosystems, causing several damages, both to ecosystems and to economic and social activities such as tourism and local fishing. Ponta Verde beach is one of the main tourist corridors and with high population density in the state of Alagoas. Therefore, this study aimed to evaluate the accumulation of plastic in coastal ecosystems, identifying its main sources and potential factors that influence its accumulation. The presence of plastic was evaluated in four different ecosystems, namely: (1) Sandy beach (2) Coral reefs (substrate and water surface) and (3) Mud bank. Microplastic was collected on the sandy beach and coral reefs only. To assess differences in the composition of macro and microplastics between the different ecosystems, ANOSIM Similarity analysis was applied, and to assess the forces that influence the dispersion and accumulation of plastic in the different ecosystems, we used data from environmental and anthropogenic variables using Generalized Linear Models (GLM). A total of 8,855 items were collected in the different ecosystems described in this study and classified according to their material, type of plastic and possible origin. Despite the notable difference in the amount of items between the ecosystems, the prevalence of plastic items was similar in all. Sandy Beach had 83.96% of its items classified as plastic, with Film types being prevalent. In Coral Reef, 83.18% of the items were classified as plastic. Of these plastics, Film and Rigid types were the most prominent. As in the two ecosystems mentioned above, the Water Surface had a high percentage of plastic items. Within this classification, the highest percentage was for items that were not identified as to the type of plastic, followed by the Film and Rigid types. The results obtained from the ANOSIM test revealed a significant difference in the composition of the plastic between the ecosystems analyzed (R=0.483; p=0.001), which indicated that the samples within each ecosystem are considerably more similar to each other than when compared between them. The results obtained from the Generalized Linear Models (GLM) indicated that, in general, in all ecosystems, wind and waves were statistically significant for the distribution and accumulation of plastic. However, when analyzing each environmental ecosystem separately, distinct patterns were presented. The prevalence of plastic over other anthropogenic waste may be related to its high production rates, which are growing even more each year, and its persistence in the environment can trigger a series of negative effects, mainly affecting various organisms. The findings of this study highlight that the accumulation and distribution of plastic occurs through different forms, with the main forces acting on them being winds, waves and mainly anthropogenic activities such as tourism and fishing. Based on this, the results obtained in this research will be fundamental to support strategies for managing and mitigating plastic pollution in such an attractive area for tourism.