Marine Pollution Bulletin 228 (2026) 119525 
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Marine Pollution Bulletin 
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Comprehensive assessment of anthropogenic debris pollution on beaches of 
the oceanic island Säo Vicente, Cabo Verde 
. b.* . . . . 
Sina Acksen *”", Anna Natalie Meyer“, Odair Fernandes Dos Reis“ Arne Biastoch 
Thorben Knoop *“, Mark Lenz* 
* GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstraße 1-3, 24148, Kiel, Germany 
> Carl von Ossietzky University Oldenburg, Ammerländer Heerstraße 114-118, 26129, Oldenburg, Germany 
* Instituto de Engenharia e Ciencias do Mar, Universidade Tecnica do Atläntico, Ribeira de Juliao - CP. 163 Mindelo, Sao Vicente, Cabo Verde 
4 Christian-Albrechts-University Kiel, Christian-Albrechts-Platz 4, 24118, Kiel, Germany 
* Federal Maritime and Hydrographic Agency (BSH), Bernhard-Nocht-Straße 78, 20359, Hamburg, Germany 
ARTICLE INFO 
ABSTRACT 
Keywords: 
Marine pollution 
Yastic 
Dcean current modeling 
>ARCELS 
3each litter 
Macrodebris 
Mesoplastic particles 
Plastic debris is a major threat to coastal ecosystems. Although, numerous studies have assessed the extent of this 
pollution in various regions of the world, our knowledge about the situation on the African continent and its 
aceanic islands is still limited. To address this gap, repeated beach debris surveys were conducted on six beaches 
an the island of Säo Vicente, Cabo Verde, over the course of six weeks from May to July 2023, with surveys 
:;onducted every four days. This was done to compare debris accumulation rates as well as debris composition 
»etween beaches that differ in their orientation, exposure and level of human use. Furthermore, we assessed the 
density of mesoplastic particles (1-10 mm) and correlated it with the amount of macroplastic debris (>10 mm) 
ancountered. A backward ocean current simulation with PARCELS allowed to identify possible origins of the 
plastic items from ocean-sources. We observed an average macrodebris (> 10 mm) accumulation rate of 0.05 + 
9.06 items/m?/d (0.2 + 0.4 g/m?/d), while the rates varied strongly between beaches. The number of macro- 
plastic items was positively correlated with the abundance of mesoplastic particles (r” = 0.982, p = 0.0004), for 
which we found an average density of 121.7 + 339.1 mesoplastic particles/m”. The particle tracking by back- 
ward ocean current simulations demonstrated the existence of a transport pathway from the northwest coast of 
\frica towards the Cabo Verde archipelago. This suggests the northwest African shore as a potential source of the 
ınthropogenic debris found on Sao Vicente. 
L. Introduction 
;pecies (Mazumder et al., 2023). Furthermore, the fragmentation of 
macroplastic items (>10 mm) leads to the formation of meso- (1-10 
mm) and microplastics (<1 mm) (Hartmann et al., 2019; Gregory and 
Andrady, 2003). Plastic items of all size classes pose a serious threat to 
marine wildlife through direct and indirect interactions with anthro- 
pogenic material (Sheavly and Register, 2007), while specific traits of 
plastic items most often determine the nature of these interactions 
‚Lambert et al., 2017). These traits comprise size, as small particles are 
more easily ingested by animals than large ones, as well as shape, since 
alongated, string-like debris can lead to entanglement (Pirsaheb et al., 
2020), while film-like items can smother organisms by covering surfaces 
‘Green et al., 2015). 
Plastic pollution in coastal areas not only endangers wildlife, but also 
has negative consequences for tourism and the recreational use of 
Debris accumulation in coastal environments is a worldwide prob- 
‚em (e.g., Derraik, 2002; Brabo et al., 2026; Sen et al., 2025), particu- 
‚arly at the coasts of remote archipelagos such as the Azores, Maldives, 
and Cabo Verde, which represent hotspots for the accumulation of sea- 
porne anthropogenic debris (Lavers and Bond, 2017). Most of this debris 
is plastic (Derraik, 2002) and this is problematic due to the slow 
degradation rate of the material, its mobility and biological impact (Le 
et al., 2024). The low density of many plastic polymers allows debris 
‚tems to float in seawater, even in case they lack air-filled cavities, and 
travel long distances across the oceans (Thushari and Senevirathna, 
2020). These items accumulate and release organic toxins, heavy metals 
as well as pathogens and may serve as a vector for non-indigenous 
* Corresponding author at: GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstraße 1-3, 241.48, Kiel, Germany. 
E-mail address: sacksen@geomar.de (S. Acksen). 
attps://doi.org/10.1016/j.marpolbul.2026.119525 
Received 11 November 2025; Received in revised form 3 March 2026: Accepted 3 March 2026 
Available online 16 March 2026 
0025-326X/© 2026 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http: //creativecommons.org /licenses/by/4.0/7.