Reacción a "Microplastics could be behind the change in the colour of the ocean in the Great Pacific Garbage Patch"

Having worked in this field for almost a decade, I am not convinced by the study, although I recognise that I still need to analyse it in greater detail.

1. The study does not observe the plastic itself, but rather finds a statistical correlation between changes in the signal detected by the satellite and trends in microplastics observed in the field. On this basis, it proposes a causal relationship. However, existing studies generally agree that microplastic concentrations are not high enough to be detected by current space-based sensors, particularly when using satellites with low spatial resolution, as is the case in this study.
2. There are other factors that could be influencing the changing trends in the signal observed by satellites, ranging from methodological factors (for example, temporal drifts in sensor performance or atmospheric corrections) to ecological factors (for example, changing trends in phytoplankton composition). Therefore, the causal relationship is, in my opinion, debatable.
3. Current trends within the scientific community are moving towards the use of sensors with higher spatial resolution and towards monitoring extreme events involving the inflow and accumulation of marine litter on coastlines and in coastal waters. The present study overlooks this research (for example, Cózar et al., 2024, ‘Proof of concept for a new sensor to monitor marine litter from space’, published in Nature Communications).