Abstract
Laboratory-based studies have suggested that marine organisms can be harmed by ingesting microplastics. However, unless the current and future microplastic abundance in the ocean environment is quantified, these experimental studies could be criticized for using an unrealistic density or sparsity of microplastics. Here we show the secular variations of pelagic microplastic abundance in the Pacific Ocean from 1957 to 2066, based on a combination of numerical modeling and transoceanic surveys conducted meridionally from Antarctica to Japan. Marine plastic pollution is an ongoing concern especially in the North Pacific, and pelagic microplastics are regarded as non-conservative matter due to the removal processes that operate in the upper ocean. The results of our numerical model incorporating removal processes on a 3-year timescale suggested that the weight concentrations of pelagic microplastics around the subtropical convergence zone would increase approximately twofold (fourfold) by 2030 (2060) from the present condition.
Highlights
Laboratory-based studies have suggested that marine organisms can be harmed by ingesting microplastics
The number of microplastics with diameters < 5 mm excluding fibers and expanded polystyrene from Sta. 20 to Sta. 38 was 932 (109), accounting for 82% (91%) of those collected across the entire meridional transect
An exponential curve fitted to the total particle count of microplastics had C0 and λ of 7.6 × 104 pieces km−2 and 0.0097 degree−1, respectively, with a correlation coefficient of 0.53, which was significant at the 99% confidence level according to a t test
Summary
Laboratory-based studies have suggested that marine organisms can be harmed by ingesting microplastics. Laboratory-based studies have found that marine organisms are harmed by the ingestion of even additive-free and virgin plastic beads leading to inflammatory responses, impedance of feeding, and so fourth[15,16,17,18,19,20]. Such damage to marine organisms can be expected in nature given the abundance of mismanaged plastic waste and, pelagic microplastics after fragmentation present in the oceans. A remarkable contrast in the abundance of pelagic microplastics is expected across a single meridional transect, while the abundance along zonal transects is likely to be dependent on oceanic conditions, such as convergence zones (i.e., oceanic fronts) that fluctuate in both time and space
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
