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Microplastics Found to Transfer Along Marine Planktonic Food Chains
Microplastics, small plastic particles pervasive in ocean ecosystems, have been shown to be easily consumed by marine organisms, specifically zooplankton. This is particularly concerning given the size similarity between microplastics and natural food particles consumed by these creatures.
Chaetognaths, a group of carnivorous zooplankton, primarily feed on copepods and are essential in connecting secondary producers—like copepods—to higher levels of the marine food chain.
A recent study led by Professor Sun Xiaoxia from the Jiaozhou Bay Station at the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS) has shed light on the seasonal patterns and dangers associated with microplastic ingestion by chaetognaths in Jiaozhou Bay, utilizing data gathered through field observations.
This groundbreaking research has been published in the Journal of Hazardous Materials.
The team studied the relationship between copepods and the ingestion of microplastics by chaetognaths, noting that copepods are the primary dietary source for these zooplankton. Results revealed that while there was no notable seasonal fluctuation in the microplastic ingestion rates among chaetognaths, the Pollution Load Index (PLI) of microplastics was relatively low. In contrast, both the Polymeric Hazard Index (PHI) and the Potential Ecological Risk Index (PERI) showed elevated levels.
Importantly, this research provides one of the first instances of field data indicating the transfer of microplastics along marine planktonic food chains.
Analysis of Microplastic Ingestion and Correlations
Further investigations comparing chaetognaths to copepods illustrated a positive correlation between the number of microplastics found in chaetognaths and both copepod population density and the concentration of microplastics present in copepods.
“Microplastics ingested by chaetognaths were predominantly filamentous, ranging from 101-400 μm in size and largely composed of polyester,” reported Meng Liujiang, the first author of this study.
The long-term effects of microplastic ingestion by organisms higher up in the food chain could result in a significant accumulation of these particles within their bodies. Calculations regarding biomagnification factors suggest that chaetognaths accumulate microplastics at a significantly higher rate than copepods within this food web, thus indicating possible risks associated with biomagnification.
“Our findings provide essential field evidence for the transfer of microplastics throughout the marine planktonic food chain, forming a foundational basis for further exploration into the fates of microplastics in oceanic environments and their potential ecological impacts,” stated Prof. Sun, the study’s corresponding author.
More information: Liujiang Meng et al, Seasonal microplastic ingestion by carnivorous chaetognaths in Jiaozhou Bay, China: Field evidence revealing microplastic trophic transfer, Journal of Hazardous Materials (2024). DOI: 10.1016/j.jhazmat.2024.135532
Citation: Field observations reveal microplastic transfer in marine planktonic food chains (2024, August 28) retrieved 28 August 2024 from https://phys.org/news/2024-08-field-reveal-microplastic-marine-planktonic.html
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