A troubling study published late last year suggests that we could be under estimating the amount of trash in the ocean as much as 80%.
Most marine litter estimates are based on beach cleanup data, especially the International Coastal Cleanup data. But cleanup data is fraught with bias and uncertainty. The study, out of the University of Tasmania, and conducted in Australia tries to quantify these biases.
5 observers were asked to quantify black, white and blue plastic in 33 sample quadrats, after which their responses were compared. It is interesting to see that black particles had the highest rate of false identification and blue plastic was identified the most consistently. The rate of identification, in some cases, was dependent on the observers experience, but not consistently across the colors and types. But overall, observers under identified plastic pieces by 80%.
This could mean that there is significant more plastic in our oceans, and on our coast lines than previously thought. But it also means that comparing plastic accumulation over time and space may not be a valid way of comparing data, because of this high rate of error.
Read the article here
Read the scientific publication here