| dc.description.abstract | Buoyant plastic debris is an increasing source of pollution threatening marine environments. As
floating plastic debris moves from the shore to the open ocean, they are found to accumulate in
large-scale converging circulation patterns called subtropical gyres or garbage patches. Previous
in-situ observations give insight into the spatial heterogeneity distribution of floating marine
debris at the ocean surface. However, minimal research has yet to take into account how
submesoscale eddies, ocean circulation patterns described as 1-100 km diameter vorticities, can
influence the accumulation and transport of floating plastic debris at the sea surface. Traditionally,
there are two types of submesoscale eddies, cyclonic (a counterclockwise low pressure rotational
dispersal system) and anti-cyclonic (a clockwise high pressure rotational accumulation system).
The aim of this study is to investigate how the abundance, weight, characteristics, and variability
of buoyant plastic debris is influenced by cyclonic and anti-cyclonic submesoscale eddies analyzed
from three different regions in relation to the Great Pacific Garbage Patch (GPGP). Using daily
satellite observations to identify anti-cyclonic and cyclonic submesoscale formations, floating
plastic debris was extracted from the sea surface outside the GPGP, in the transition zone into the
GPGP, and inside the GPGP. Due to the anti-cyclonic accumulating rotational dynamic, it is
hypothesized that anti-cyclonic submesoscale eddies will accumulate a higher concentration of
floating plastic debris in comparison to cyclonic submesoscale eddies. The results demonstrate a
trend of cyclonic eddies accumulating higher concentrations than anti-cyclonic eddies within the
outside and the transition zone into the GPGP. While anti-cyclonic eddies show a trend in
accumulating higher concentrations of floating plastic debris inside the GPGP. Hard (‘H’) type
plastics with the size range between 0.05 cm to 0.15 cm (Micro 1) was a common trend also found
within the anti-cyclonic submesoscale measurements. While this study highlights how physical
oceanic processes impact the dispersal of floating plastic debris, further research is required into
plastic debris distribution patterns since these findings exhibited large spatial heterogeneity
distribution of floating plastic debris found within submesoscale eddies. | |
