Micropollutants in the deep sea: influence of feeding mode on microplastic intake by benthic organisms and detection of persistent organic pollutants in biological and sediment samples

Author(s)

Gabriel Stefanelli Silva

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto Oceanográfico (IO/DIDC)
• Defense date: 2024-02-05

Examining board members

Paulo Yukio Gomes Sumida; Michela Borges; Anne Karen da Silva Justino; Rosalinda Carmela Montone

• Advisor: Paulo Yukio Gomes Sumida

Abstract

The deep sea has been known as the last marine environment to face the impacts of human action. Recent studies, carried out predominantly in the northern hemisphere, have found marine debris and chemical pollutants in the fauna, sediments and water column of this ecosystem which is the largest on Earth. Considering ongoing efforts to document deep-sea pollution in the southern hemisphere, the first chapter in this thesis shows that microplastics have been present in the benthic community of Antarctica since the 1980s, presenting here the earliest record of microplastics in the continent, originating from invertebrates deposited in biological collections. Levels of contamination are similar in specimens which were recently sampled or were originally caught at shallower depths, which could indicate a consistent entry of microplastics in Antarctica for at least the past four decades. In the second chapter, this work presents the first record of microplastics and persistent organic pollutants in a deep-sea benthic community and in the surrounding sediment in the Southwestern Atlantic, within the Santos Basin. In both chapters, organisms feeding off organic matter deposited in surface sediments had the highest ingestion values, both regarding number of particles and ingestion frequency, indicating the role of this feeding mode in the concentration of environmental pollutants. (AU)

• FAPESP's process: 18/19278-2 - Do microplastics and persistent organic pollutants bioaccumulate in the deep-sea food web?
• Grantee: Gabriel Stefanelli Silva
• Support Opportunities: Scholarships in Brazil - Doctorate