In Situ Exploration of the Characteristics of Microplastics Formed by the Fragmentation of Floating Floats in Seawater Aquaculture

With the widespread application of plastic products in various fields, microplastic pollution caused by waste plastics has become a global environmental problem. Microplastic pollution is notably prevalent in marine environments, particularly in aquaculture areas. Marine aquaculture plastic facilities are subject to prolonged exposure to ultraviolet radiation, wave impact, and microbial erosion, gradually breaking down and forming microplastics. Although extensive studies have been conducted on the impact of microplastics on marine organisms and ecosystems, studies on the laws of microplastic formation from float debris in marine aquaculture in natural environments are limited. This study used a self-made plastic crushing in-situ collection device to monitor and analyze the fragmentation of seawater aquaculture float in natural environments. The results showed that after 37 days, the abundance of microplastics in the no float group device was (307.09±16.37) items/kg, whereas the abundance of microplastics in the float group device was (392.72±27.22) items/kg. The collected microplastics were predominantly fibrous and measured ˂ 0.5 mm, with most being transparent in color. During seawater aquaculture, approximately (136.41±10.59) ind. microplastics were generated by float, primarily in the form of thin films with predominantly black color. There were (85.75±6.06) ind. film-shaped microplastics, (46.74±3.32) ind. granular microplastics, (2.77±0.21) ind. foam-shaped microplastics, and (1.16±0.96) ind. fibrous microplastics. Additionally, there were (95.42±6.87) ind. black colored microplastics, and (40.10±3.46) ind. transparent microplastics, with other colors being the least prevalent at (0.90±0.22) ind.. This device effectively collects microplastics generated by the fragmentation of float in marine aquaculture. The study results provide basic data and theoretical support for evaluating and predicting the generation, migration, and ecological risks of microplastics caused by aquaculture floats.