Photodegradation, Spectroscopy, RAMAN, Small microplastics, Polymers - analysis, Atlantic Ocean, Environmental Monitoring - methods, Polyethylene - analysis, Polyethylene - chemistry, Water Pollutants - analysis, Polypropylenes - analysis, Plastics - chemistry, Polymers - chemistry, Polypropylenes - chemistry, Spectrum Analysis, Raman, Plastics - analysis, W...