Small microplastics on beaches of Fernando de Noronha Island, Tropical Atlantic Ocean

Monica Ferreira Costa,Raqueline Cristina Pereira Monteiro,Juliana Assunção Ivar Do Sul

doi:10.1590/s2675-28242020068235

Monica Ferreira Costa, Raqueline Cristina Pereira Monteiro + Show 1 more

Open Access

https://doi.org/10.1590/s2675-28242020068235

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Abstract

Oceanic islands are important areas of environmental, social, economic, and scientific interest. Therefore, it is essential to identify pollutants in these environments, including large (1 mm to ≤ 5 mm) and small microplastics (SMP) (1 µm to ≤ 1 mm). Here, SMP were identified and characterized in the windward (WW) and leeward (LW) beaches of Fernando de Noronha Island. Samples were collected from 900 cm2 quadrants on the strandline of 15 sandy beaches and were sieved through stainless steel sieves with 1 mm mesh. The SMP were characterized according to their shape, colour, and size. Synthetic fibres and fragments were identified, and synthetic fibres were predominant. Statistical differences were not found between the WW and LW beaches (160.0±137.5 particles m-2 and 128.0±84.3 particles m-2, respectively; Mann-Whitney U test: U=198.5; p=0.81) in relation to the total amount of SMP deposited on the beaches. Also, both types/shapes were present in the two groups of beaches (Friedman’s test, X2r=6.09; p=0.91). The environmental forcings controlling the transport and potential deposition of synthetic fibres may have been different from those acting on fragments that more resembled the grains of sand in the beaches. Although it is difficult to prevent allochthonous sources of SMP at the small scale, management actions on the island are mandatory to prevent autochthonous sources.

Highlights

Scientists, civil society, and governments have recently (< 10 y) increasing concerns about the impacts of microplastic pollution on marine ecosystems (Hu et al, 2019; Van Wijnen et al, 2019)
small microplastics (SMP) were reported in all sediment samples from Fernando de Noronha Island (Figure 2)
Synthetic fibres corresponded to 90% (n=459) (Figure 3) and fragments accounted for approximately 10% (n=45) of the particles

Summary

Introduction

Scientists, civil society, and governments have recently (< 10 y) increasing concerns about the impacts of microplastic pollution on marine ecosystems (Hu et al, 2019; Van Wijnen et al, 2019). Microplastics are plastic particles with a size of 1 μm to 5 mm; because they have diverse behaviours within marine habitats (i.e. transport mechanisms and potential impacts), they can be classified as large (1 mm to ≤ 5 mm) or small (1 μm to ≤ 1 mm) microplastics (SMP) SMP and large microplastics have the same sources (Boucher and Friot, 2017). Primary SMP are already at the microscopic scale when they reach the sea, such as microbeads used in cosmetics; they can enter marine environments from sewage discharge on land (Browne et al, 2011; Boucher and Friot, 2017). Secondary SMP originate from the degradation and fragmentation of relatively larger plastics in the environment (Frias and Nash, 2019)

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