After the stone age, the bronze age, the iron age, we are now at the age of plastic. A material we can not do without. The Pedagogical Sailboat project focuses on sea pollution by microplastics.
- Microplastics are any plastic fragment smaller than 5 mm.
- Why 5 mm? Over 92% of all plastic items found at sea are generally smaller than 5 mm*. There is no consensus yet, within the scientific community, on the lower size limit**.
- Microplastics can pass through wastewater treatment plants and eventually reach the marine ecosystems.
- Nowadays 80% of marine litter is plastic.
- Microplastic abundances in the mediterranean sea are amongst the highest in the world.*
- Microplastics mostly float at the sea surface because most synthetic polymers have a lower density than seawater.
- The manta net is commonly accepted as sampling method in open sea; however, there is a lack of standardisation (mech size, sampling protocol etc.)
* Eriksen, M. et al. Plastic pollution in the world’s oceans: more than 5 trillion plastic pieces weighing over 250,000 tons aoat at sea. PloS ONE 9, e111913 (2014).
** Suaria, G. et al. The Mediterranean Plastic Soup: synthetic polymers in Mediterranean surface waters. Sci. Rep. 6, 37551; doi: 10.1038/srep37551 (2016).
Microplastics absorb chemical pollutants. The fish ingest the plastic, and here we are in the food chain. These pollutants are called POPs: Persistent Organic Pollutants. Persistent because their concentration increases from bottom to top of the food chain. The phenomenon is called biomagnification. Health authorities recommend limiting the consumption of large fish such as tuna because of the phenomenon of biomagnification.
Microplastics are not the only cause (and probably not the main cause) of this issue. All pollutants ingested by fish do not come from microplastics. We do not yet know for sure the direct impact of plastic on our health. However, it is assured that microplastics are harmful to aquatic species.
Ayam Sailing Europe Aisbl