In situ microplastic ingestion by neritic zooplankton of the central Mexican Pacific

• Published in: Environmental pollution (1987) 2023-02, Vol.319, p.120994-120994, Article 120994
• Main Authors: Zavala-Alarcón, Fabiola L., Huchin-Mian, Juan Pablo, González-Muñoz, Maria Del Pilar, Kozak, Eva R.
• Format: Article
• Language: English
• Subjects: Amphipoda; Animals; Chaetognatha; Copepoda; Decapoda; Eating; Environmental Monitoring - methods; fish; Fish larvae; Microplastics; oceans; omnivores; Plastics; pollution; Polyethylene; Polymers; Raman micro-spectroscopy; Raman spectroscopy; species; Water Pollutants, Chemical - analysis; Zooplankton
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2022.120994

Microplastics (MPs) are present across the global ocean and can be encountered by many species, including zooplankton. Although they fall within the size range of zooplankton prey, there are few studies on MPs ingestion carried out in situ. In this study, we analyzed MPs ingestion during two seasons (rainy and dry) of organisms from 5 taxonomic groups of zooplankton from two bays of the Mexican central Pacific: Manzanillo and Navidad. In total, 2643 individuals were analyzed, and of those 23 individuals contained MPs. The ingestion rate by taxonomic group was 1 MP/36 copepods (0.02), 1 MP/30 decapods–mysis (0.03), 1 MP/29 decapods–megalopa (0.03), and 1 MP/200 fish larvae (0.005). No plastics were found in chaetognaths, amphipods, or decapods–zoea. The average length of the ingested particles was 468.1 ± 113.8 μm, with a minimum of 15.6 and a maximum of 647.6 μm. All MPs >300 μm were fibers, with diameters  0.05) between the bays or seasons. Using RAMAN spectroscopy, it was possible to identify 6 different types of polymers, with poly (ethylene:propylene) being the most abundant (42.8%). This polymer is commonly used to manufacture plastic bags, ropes and fishing nets. The results confirm that certain zooplankton groups are consuming MPs and suggest that omnivorous species are more likely to ingest MPs, possibly due to their capacity for foraging flexibility and opportunistic feeding strategies. However, the ingestion of MPs cannot be attributed to a single factor; it is necessary to consider variables such as the sampling area, feeding strategy, size, and seasonality to understand the dynamics of MPs ingestion by zooplankton groups. [Display omitted] •Zooplankton organisms are consuming microplastics in the Central Mexican Pacific.•Feeding strategy and life stages can increase the consumption of microplastics.•In situ studies are vital to understand microplastic ingestion by zooplankton.•Variables such as sampling area and seasonal dynamics should be considered.•Confirmation of plastic particles through infrared spectroscopy is essential.