|Narrative summary of dataset||This study is a first attempt in Denmark
on assessing the presence of microplastics in our
open & coastal waters from Baltic to North Sea.
The occurrence and impact of microplastics have
in the Danish initial assessment for EU’s Marine
Strategy Framework Directive (MSFD)
been identified as a relevant indicator for
describing “Good Environmental Status” (GES)
for descriptor 10 on Marine Litter.
Microplastic particles in marine waters,
which consist of synthetic polymer materials,
origin mainly from secondary microplastics, i.e.
fragments of litter like solid waste, fishing gear, paint
flakes etc. from either sea- or land based sources.
Primary microplastics (engineered) are not expected to
be as common as secondary microplastics.
Microplastics can origin from both local sources and
from long-range transport with ocean or air currents.
|Summary of processing methodology||Microplastic particles have been isolated from a100g
sediment sample, which has been digested for 2
hours with 200 ml solution of KOH and NaOCl for
reducing the amounts of natural organic materials.
The remaining sample was when washed two times
with a saturated NaCl solution.
Particles were collected using sediment test sieves in
following size fractions
I) 38 µm – 1 mm , II) 1 – 5 mm and III) >5 mm
Particles, regarded as of synthetic origin, were with
microscope isolated, counted and characterized
according to their colour and shape/structure, i.e. as
fibres, flakes, granules or spherules.
FT-IR spectroscopy was applied to identify specific
polymers in some selected flakes and granules with
size larger than 0.5 x 0.5mm, i.e. fibres were too small
to study. Particles of the polymers polypropylene,
acrylate, and polyester/alkyd were identified.
About 50% of the selected particles could with our FTIR database not be matched on synthetic materials.
Normalisation to adequate sediment characters can
reduce the variability caused by natural heterogeneity
between samples and increase the power of
identifying more or less affected areas.
Strong relationships between the content of
microplastics and both %TOC and fine fraction
(<63µm) in sediments were found throughout the area
supporting that microplastic will accumulate in
sedimentary depositional areas – i.e. with parallels to
organic pollutants sorped to organic materials.
Strong correlations were also established to PAH and to
lesser extent to alkylphenols & phthalates in sediments
probably due to co-variation with sources and TOC.|