"The team has now analysed data from the past 22 years - more than 6,000 net tows- to try and quantify the amount of plastic in the western Atlantic and the Caribbean...Perhaps the most surprising result... is that they didn't see an increase in debris over time. " [*]The authors also correctly point out that this work is only for the North Atlantic Gyre and cannot be extrapolated to other areas.
This is obviously good news as it appears that efforts over the past decades to reduce ocean pollution have been somewhat effective. If they had been totally effective, I would have expected to amount of plastic to decrease due to degradation. It appears now that the rate of input is equal to the rate of degradation. If the rate of input is less than that of the degradation, then the amount in the gyre would be decreasing. This is certainly the desired goal.
[*] From the RSC summary of the article. (Open access)