Microplastics results

The results have been normalized by subtracting the amount of microfibers found in the blank control from the microfibers found in the samples.

For the frequency of microfiber ingestion, there seems to be a higher percentage in the mussels closer to the coast. For the center and the external part, the percentage is the same.

For the amount of microfibers per individual, there seems to be a higher number for mussels closers to the shore and a relatively low number for mussels in the center.

There is a relatively high standard variation for mussels closer to the shore. This is due to the fact there were only two mussels with positive values for microfibers after standardization with the blank, and both of these had very different values.

For both center and external, there was only one mussel with positive values. The origin of the microplastics was for all of the sample areas mostly natural origin, e.g. cellulose-based.

There is some difference in the amount of synthetic origin, e.g. polyester or polypropylene. The center has the highest amount of synthetic microfibers, whereas the internal has the lowest amount of synthetic microfibers.

The frequency of ingestion was equally high in both internal and external location. In the center, none of the analyzed mussels contained any microplastics.

The number of microplastics per individual is also the same for both internal and external, seeing as there were only 2 positive organisms that both contained 1 microplastic. The number is 0 in the center, because there were no positive organisms in the center.

The microplastics found in the internal area were both black rubber fragments.

The microplastics found in the external area were black and yellow fragments of rubber and polyamide, respectively.