This figure shows the distribution of the underlying data in Oliver et al 2017 (see below). Interestingly, when you look at all data, it is difficult to discern any patterns. While the study found that on average lakes weren’t changing in chlorophyll, roughly 15% of lakes were either increasing or decreasing in chlorophyll.
Samantha Oliver made this GIF using data and results from her recent paper in Global Change Biology published in 2017. She also shared her code for the above GIF here; as well as the data that the article is based on. You can read more about this article at this blog and this press release. This article was also recently featured in the Minneapolis Star and Tribune.