Plastics with particle sizes of 100 nm to 5 mm are known as microplastics. The contamination of seafood-based feeds by larger microplastics (20 μm to 5 mm) is a growing concern. Here, we analyzed fish and shrimp meals. Microplastics were extracted using density separation methods and characterized using scanning micro Fourier transform infrared spectroscopy (μ-FT-IR). The average microplastic abundance in shrimp meal was 10.7 microplastics·100 g⁻¹. In fish meal, 1.02% of the microplastics were smaller than 1 mm, while most of the microplastics in shrimp meal were 1–5 mm. Eight colors of microplastics were observed; black, red, and orange microplastics have been rarely reported in previous studies. The microplastics found included films, fibers, and fragments, with film-type microplastics being the most common. The main chemical components of fiber-type microplastics were olefins and polyester, while film- and fragment-type microplastics were mainly paraffin and polyethylene. Additional in-depth studies of microplastics in feeds are necessary to provide data support for feed safety assessments.

粒径为 100 nm 至 5 mm 的塑料被称为微塑料。较大的微塑料（20 微米至 5 毫米）对海产品饲料的污染越来越受到关注。在这里，我们分析了鱼和虾的膳食。使用密度分离方法提取微塑料，并使用扫描微傅里叶变换红外光谱 (μ-FT-IR) 进行表征。虾粉中平均微塑料丰度为 10.7 微塑料·100 g ^-1. 在鱼粉中，1.02% 的微塑料小于 1 毫米，而虾粉中的大部分微塑料为 1-5 毫米。观察到八种颜色的微塑料；以前的研究中很少报道黑色、红色和橙色微塑料。发现的微塑料包括薄膜、纤维和碎片，其中最常见的是薄膜型微塑料。纤维型微塑料的主要化学成分是烯烃和聚酯，而薄膜型和碎片型微塑料的主要化学成分是石蜡和聚乙烯。需要对饲料中的微塑料进行额外的深入研究，以便为饲料安全评估提供数据支持。