Perold Vonica, Moloney Coleen L, Ryan Peter G
FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, 7701, South Africa.
Department of Biological Sciences, University of Cape Town, Rondebosch, 7701, South Africa.
Environ Pollut. 2025 May 15;373:126125. doi: 10.1016/j.envpol.2025.126125. Epub 2025 Mar 25.
Marine plastic pollution is a global issue that requires innovative ways of monitoring and mitigation. Information on how the size, mass and polymer type of floating plastic items are changing over time may improve our understanding of the complex dynamics governing fragmentation rates, dispersal, longevity, input rates and abundance at the sea surface. Procellariiform seabirds directly ingest floating meso- and microplastics, which they retain in their gizzards. As a result, petrels can be used as biomonitors to document trends in the abundance and characteristics of marine plastics. We compare the characteristics of plastics collected from regurgitated Brown Skua Catharacta antarctica pellets containing the remains and plastics ingested by four petrel taxa breeding at Inaccessible Island, South Atlantic Ocean, at roughly decadal intervals from 1987─2024. To assess if trends persist across biotic (ingested) and abiotic (beaches) compartments, we compare this to the characteristics of meso- and microplastics (2-25 mm) sieved from South African beaches from 1984─2023. Plastics were collected from beaches far from local urban source areas in an attempt to track changes in plastic floating at sea rather than local, land-based sources. Overall, there was little evidence of trends in the size and mass of ingested or beached plastics. The average mass of industrial pellets from beaches decreased up to 2015, suggesting an old, gradually eroding cohort of legacy pellets, but increased in 2023 after two major pellet spills off the South African coast. Nearly all ingested and beached plastics were polyethylene (PE) or polypropylene (PP), but the ratio of PP to PE in hard fragments increased over time, while recent increases in PE:PP ratios in industrial pellets match recent pellet spills at sea. Identifying polymer types in ingested and beached plastics is valuable for future studies, as it may be useful for marine pollution management.
海洋塑料污染是一个全球性问题，需要创新的监测和缓解方法。有关漂浮塑料物品的尺寸、质量和聚合物类型如何随时间变化的信息，可能会增进我们对控制海面破碎率、扩散、持久性、输入率和丰度的复杂动态过程的理解。鹱形目海鸟会直接摄取漂浮的中型和微型塑料，并将其留在砂囊中。因此，海燕可以用作生物监测器，以记录海洋塑料的丰度和特征趋势。我们比较了从含有残骸的南极贼鸥反刍物中收集的塑料的特征，以及1987年至2024年期间大致以十年为间隔在南大西洋难以接近岛繁殖的四种海燕类群摄取的塑料。为了评估这些趋势是否在生物（摄取的）和非生物（海滩）部分中持续存在，我们将其与1984年至2023年从南非海滩筛出的中型和微型塑料（2-25毫米）的特征进行了比较。塑料是从远离当地城市源区的海滩收集的，试图追踪海上漂浮塑料的变化，而不是当地陆源的变化。总体而言，几乎没有证据表明摄取的或搁浅的塑料在尺寸和质量上存在趋势。海滩上工业颗粒的平均质量在2015年之前有所下降，这表明有一批陈旧的、逐渐被侵蚀的遗留颗粒，但在2023年南非海岸发生两次重大颗粒泄漏后有所增加。几乎所有摄取的和搁浅的塑料都是聚乙烯（PE）或聚丙烯（PP），但硬碎片中PP与PE的比例随时间增加，而工业颗粒中PE:PP比例最近的增加与最近海上颗粒泄漏情况相符。识别摄取的和搁浅的塑料中的聚合物类型对未来研究很有价值，因为这可能对海洋污染管理有用。
