Sciences marines : recherche et développement

Abstrait

Distribution of Microplastics in the Marine Environment: Plastic Density Relative to Location and Current Magnitude off the New England Coast

Miya Khoo

In this study, we aimed to quantify the densities of microplastics in the coastal and outer mid-Atlantic regions and to better understand the mechanisms by which they are distributed. Originally, we hypothesized that microplastic fragments would linearly decrease with distance from shore as we move away from human sources of pollution.  We measured the microplastic densities through a combination of surface and subsurface water measurements from a marine research vessel. We observed that while surface sample plastic densities did decrease with proximity from shore subsurface samples from the same locations surprisingly did not.  In actuality, we found that subsurface microplastics reached maximum density at the farthest points from shore. We thus concluded that subsurface plastic debris vary more due to the complex interplay between wind and current influences rather than to just simple shore proximity.  This implies that regional pollution sources feed plastic debris into local outbound subsurface oceanic streams that are then carried far offshore by current gyres to the larger oceanic plastic patches and gyres.