Sousa-Guedes Diana, Sillero Neftalí, Abu-Raya Mara, Marco Adolfo, Bessa Filipa
Centro de Investigação em Ciências Geo-Espaciais (CICGE), Faculdade de Ciências da Universidade do Porto, Alameda do Monte da Virgem, 4430-146 Vila Nova de Gaia, Portugal; BIOS.CV - Conservation of the Environment and Sustainable Development, CP 52111 Sal Rei, Boa Vista Island, Cabo Verde; Estación Biológica de Doñana, CSIC, C/ Américo Vespucio, s/n, 41092 Sevilla, Spain.
Centro de Investigação em Ciências Geo-Espaciais (CICGE), Faculdade de Ciências da Universidade do Porto, Alameda do Monte da Virgem, 4430-146 Vila Nova de Gaia, Portugal.
Mar Pollut Bull. 2025 May;214:117823. doi: 10.1016/j.marpolbul.2025.117823. Epub 2025 Mar 18.
Coastal ecosystems are under increasing threat, with the accumulation of marine debris-particularly plastics-posing significant ecological risks. Oceanic islands are especially vulnerable due to ocean currents depositing marine debris on their exposed shores. This study presents the first assessment of marine debris accumulation on sandy beaches of Boa Vista Island, Cabo Verde. Using a combination of drone-based aerial imagery and sand sampling, we quantified micro-, meso-, and macro-debris densities across 29 beaches. North- and east-facing beaches of the island showed the highest accumulation of marine debris (>85 % plastics), driven by ocean currents. Mean drone-based densities varied between 5 and 2371 macro-debris items per 100 m of beach length, totalling 23,085 items. As for sand samples, mean densities ranged from 0 to 1639 items/m, totalling 4272 large microplastics, 1221 mesoplastics and 350 macroplastics. The easternmost beach, Ponta de Roque, alone accounted for 31 % of the total debris recorded across all locations, with sand samples averaging 1639 items/m (1453 microplastics larger than 1 mm), and drone-based surveys averaging 68 macro-debris items/100 m. Fishing-related items comprised ∼24 % of drone-surveyed debris, suggesting input from the Northwest African coast. Plastic fragments predominated, with significant correlations between drone-surveyed macro-plastics and sand-sampled large microplastic densities. Drone surveys effectively identified marine debris hotspots, aligning with ground-based data. This study provides important baseline data for long-term monitoring in the archipelago and offers a transferable methodology for assessing plastic pollution in other island systems.
沿海生态系统正面临日益严重的威胁，海洋垃圾尤其是塑料垃圾的堆积带来了重大的生态风险。由于洋流将海洋垃圾沉积在海洋岛屿暴露的海岸上，这些岛屿尤其脆弱。本研究首次对佛得角博阿维斯塔岛沙滩上的海洋垃圾堆积情况进行了评估。通过结合无人机航拍图像和沙滩采样，我们对29个海滩的微塑料、中塑料和宏塑料密度进行了量化。该岛朝北和朝东的海滩海洋垃圾堆积量最高（塑料垃圾占比>85%），这是由洋流导致的。基于无人机的平均密度在每100米海滩长度5至2371个宏塑料垃圾之间，总计23085个。至于沙滩样本，平均密度在0至1639个/米之间，总计4272个大型微塑料、1221个中塑料和350个宏塑料。最东端的海滩蓬塔德罗克，其记录的垃圾总量占所有地点记录总量的31%，沙滩样本平均为1639个/米（1453个大于1毫米的微塑料），基于无人机的调查平均为68个宏塑料垃圾/100米。与渔业相关的物品约占无人机调查垃圾的24%，表明这些垃圾来自西北非洲海岸。塑料碎片占主导，基于无人机调查的宏塑料与沙滩采样的大型微塑料密度之间存在显著相关性。无人机调查有效地识别出了海洋垃圾热点区域，与地面数据相符。本研究为该群岛的长期监测提供了重要的基线数据，并为评估其他岛屿系统中的塑料污染提供了可借鉴的方法。
