2:30 PM - 2:45 PM
[MIS09-04] The fate of microplastics in the coastal seas
Keywords:microplastic, coastal seas, spatial distribution, age
Marine plastic debris has been the subject of extensive research in recent years, and national and local governments have taken various measures to reduce their amount in the environment. Most plastic debris originate on land, but how are they distributed in the ocean? In this study, we pursued a shipboard survey in the Seto Inland Sea to clarify the spatial and age distribution and of microplastics in the coastal area.
We find more microplastics to concentrate along tidal fronts compared to the surrounding areas, which indicates that plastic debris gathers in areas where currents converge. The age of microplastics, defined as the time from when they were released into the environment to the time they were collected, was estimated from the degree of plastic degradation. Many of the microplastics in the Seto Inland Sea were found to be between 0.8 and 2.5 years old, which is younger than those found in the open ocean.
We speculate that this is because many microplastics are aggregated with phytoplankton
in the Seto Inland Sea or escaping to the open ocean.
We find more microplastics to concentrate along tidal fronts compared to the surrounding areas, which indicates that plastic debris gathers in areas where currents converge. The age of microplastics, defined as the time from when they were released into the environment to the time they were collected, was estimated from the degree of plastic degradation. Many of the microplastics in the Seto Inland Sea were found to be between 0.8 and 2.5 years old, which is younger than those found in the open ocean.
We speculate that this is because many microplastics are aggregated with phytoplankton
in the Seto Inland Sea or escaping to the open ocean.