https://phys.org/news/2018-08-murky-lakes-surpass-blue.html

"Blue lakes typically are those that do not show evidence of nutrient pollution or elevated organic matter while murky lakes have high levels of both," said lead author Dr. Dina Leech, of Longwood University in Farmville, Virginia. "A shift toward murkiness is a management concern because murky lakes tend to have more algae, including potentially harmful cyanobacteria. And with poor food quality at the base of the food web, over time murky lakes may not be able to support a healthy fishery."

                                                            
                                    
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                                    Limnology and Oceanography (2018). onlinelibrary.wiley.com/doi/10.1002/lno.10967