Q1. I was wondering if you can differentiate the types of floating plastic and/or if all plastics have the same signature? As plastics are a diverse group of materials, can they all be measured equally (well)?
Response from Lauren Biermann (PML/IOCCG Marine litter task force): In the lab using hyper spectral data, we do see clear differences in spectral shape. From Sentinel-2 unfortunately, I have seen no evidence of that yet, but perhaps with more in situ validation we’ll be able to tell for certain either way!
Q2. Can we use hyper spectral data from satellite to monitor plastic ?
Response from Lauren Biermann (PML/IOCCG Marine litter task force): My colleague Aser Mata has been looking at how possible it is to use hyper spectral data for plastic detection on beaches, because I have not found it to work reliably or reproducibly at all using my technique. He has been getting some excellent results, where I actually am quite dependant on water, and how strongly it absorbs light in the NIR and SWIR. Simple approach, but quite limited to water for that reason.
Q3. Given the diverse sources, pathways and impacts of plastic litter and microplastics, what would you recommend would be priority areas to change behaviour? Is it education, market-based instruments or regulatory change? What would you think would be more effective medium and long-term?
What we have been verifying over these years in research into marine litter, to find solutions, ways to reduce the impact of marine litter, necessarily involves the active involvement of communities.
Changing behavior is difficult. In communities with few resources, on small islands that import their essential goods, the solution is plastic-free packaging. It is important to find alternatives.
Then prevent plastics from reaching rivers and the sea. Through an efficient collection system, and appropriate behavior.
More than formal education, we need environmental literacy, we need to better communicate science and we need public policies to be efficient, easily understood by communities, which meet the needs and specifications of each of the communities.
For me, I think this has to be legislated and regulated. We know recycling isn’t the answer, and consumers cannot do much when they are surrounded by plastics. Behavioural change is all good, but it can only go so far when millions of tons of waste plastics are being sent from Europe and North America to SE Asian countries every year.
Internalizing the environmental and health costs into the price of plastics would in most cases make plastic far too expensive to use and would create the need to reduce plastic and find alternatives.