The AMWN is testing for the presence of toxins (bisphenols and heavy metals) related to microplastic uptake and/or consumption by marine fauna in different marine trophic levels (the food web).
For the proof of concept study, we selected a low trophic level marine invertebrate, as these species are common prey for predators in a higher trophic level (fish).
For the roll-out phase into Africa, we hope to have a representative from each of the trophic levels to test for these toxins.
Fish will represent the toxins that we are eating (from buying fish in the shops, restaurants and markets), while sharks and dolphins at the top of the food chain will represent the extent to which our bodies are taking up and storing toxins related to microplastics.
We collected oyster samples from an oyster mariculture facility in Algoa bay. To avoid any contamination of the samples, all the equipment was acid washed and rinsed with water, five times each. The tubes were pre-weighed to obtain a container weight.
The oysters were placed in the tubes, weighed again to obtain a wet weight, and then placed in a freeze drier to remove all the moisture. Once the samples were dry, they were again weighed to obtain a dry weight. The samples were then ready for shipment to the Norwegian labs for bisphenol and heavy metal analyses.