Here we provide a first assessment of microplastics (MPs) in stomach contents of 15 common dolphins (Delphinus delphis) from both single and mass stranding events along the New Zealand coast between 2019 and 2020. MPs were observed in all examined individuals, with an average of 7.8 pieces per stomach. Most MPs were fragments (77%, n = 90) as opposed to fibres (23%, n = 27), with translucent/clear (46%) the most prevalent colour. Fourier transform infrared (FTIR) spectroscopy revealed polyethylene terephthalate (65%) as the most predominant polymer in fibres, whereas polypropylene (31%) and acrylonitrile butadiene styrene (20%) were more frequently recorded as fragments. Mean fragment and fibre size was 584 μm and 1567 μm, respectively. No correlation between total number of MPs and biological parameters (total body length, age, sexual maturity, axillary girth, or blubber thickness) was observed, with similar levels of MPs observed between each of the mass stranding events. Considering MPs are being increasingly linked to a wide range of deleterious effects across taxa, these findings in a typically pelagic marine sentinel species warrants further investigation.

在这里，我们首次评估了 15 只普通海豚 ( Delphinus delphis ) 胃内容物中的微塑料 (MPs)) 来自 2019 年至 2020 年新西兰海岸沿线的单一和大规模搁浅事件。在所有接受检查的个体中均观察到 MP，每个胃平均有 7.8 个。大多数 MP 是碎片 (77%, n = 90)，而不是纤维 (23%, n = 27)，半透明/透明 (46%) 是最普遍的颜色。傅里叶变换红外 (FTIR) 光谱显示聚对苯二甲酸乙二醇酯 (65%) 是纤维中最主要的聚合物，而聚丙烯 (31%) 和丙烯腈丁二烯苯乙烯 (20%) 更常被记录为碎片。平均碎片和纤维大小分别为 584 μm 和 1567 μm。未观察到 MP 总数与生物学参数（总身长、年龄、性成熟、腋窝或脂肪厚度）之间的相关性，在每个大规模搁浅事件之间观察到类似水平的 MP。考虑到 MP 越来越多地与整个分类群的广泛有害影响联系起来，这些在典型的远洋海洋哨兵物种中的发现值得进一步调查。