Research reveals that environmental pollutants are halved when passed through the digestive tract of Japanese sea worms
The red circles in (A) and (B) indicate the location of Yoro Tidal Flat. The dashed ellipse in (C) indicates the sampling area where fecal pellets of Marphysa sp. E was collected. Reduced mud (RM) was collected from RM1, RM2, and RM3. (D) Image of Yoro Tidal Flat (July 19, 2023). Credit: Dr. Atsuko Nishigaki
Dr. Atsuko Nishigaki of Toho University and her research team discovered that the marine insect Malfisa sp. Annelid E, which inhabits the tidal flat sediments of Tokyo Bay, reduces the concentration of polycyclic aromatic hydrocarbons (PAHs), which are carcinogenic environmental pollutants, by ingesting and excreting organic-rich reduced mud containing high concentrations of polycyclic aromatic hydrocarbons (PAHs). decreased rapidly. PAH concentrations were halved within 2 hours.
The study was published in the journal Marine Pollution Bulletin.
Benthic organisms living in the sediments of tidal flats are thought to contribute to material circulation in the sediment environment by digging holes and feeding. In a previous study, feces of the annelid Marfisa species E present in tidal flat sediments in Tokyo Bay contained high concentrations of PAHs that halved within 2 h after excretion. The study results also revealed that PAHs in the nematode feces were derived from reduced organic mud scattered in the tidal flat sediments. Marfisa sp. E selectively ingested and excreted this reduced organic mud containing high concentrations of PAHs.
The half-life of PAH concentrations observed in insect feces within 2 hours was very rapid compared to the typical half-life of PAHs in sediments of weeks to months. However, it is unclear whether this decomposition activity is due to the passage of reduced organic mud through the digestive tract of Marfisa species. It remains unclear whether E or the reduced mud itself has decomposition activity.
(A) Reduced mud (red dashed line) is a highly viscous black deposit scattered over a wide area of ​​the tidal flat. (B) Pile of fecal grains of Marphysa spp. E is excreted on the surface of the tidal flat. Credit: Dr. Atsuko Nishigaki
Live color of Marfisa sp. E sensu Abe et al. (2019). (A) Whole body with head turned to the right, (B) Enlarged anterior end. Credit: Zoological Science (2023). DOI: 10.2108/zs230020
Changes in polycyclic aromatic hydrocarbon concentrations and mud reduction in fecal pellets of Marphysa sp. Credit: Atsuko Nishigaki
In this study, gas chromatography-mass spectrometry (GC-MS) was used to investigate the temporal changes in PAH concentrations in feces and reduced organic mud, followed by statistical analysis. The results showed that such a rapid decrease in PAH concentration did not occur in the reduced mud itself. Rather, it occurred when the mud passed through the digestive tract of Marfisa spp. E.
Based on these findings, the research team concluded that Marphysa sp. It contributes to the environmental purification of Tokyo Bay by ingesting and excreting reduced organic mud containing high concentrations of PAHs.
Further information: Yuichiro Osaka et al. Changes in polycyclic aromatic hydrocarbon concentrations in fecal pellets of Marfisa sp. E and decreased mud in Yoro Tidal Flat, Japan, Marine Pollution Bulletin (2024). DOI: 10.1016/j.marpolbul.2024.116977
Provided by Toho University
Source: Environmental pollutants reduced by half after passing through the digestive tract of Japanese marine insects, research results (December 5, 2024) From https://phys.org/news/2024-12-environmental-pollutant-decreases Retrieved on December 5, 2024 – gastrointestinal tract.html
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