After studying 71 lakes in 33 countries, researchers found that phytoplankton and algae blooms are generally increasing around the world.

Through episodic and regional studies, scientists have observed that phytoplankton blooms have been occurring more often in lakes around the world in recent decades. But until recently, no one had assembled a global, wholistic view of the phenomenon. Scientists from Stanford University and NASA recently decided to measure the blooming trends globally. What they found was discouraging.

Working with the long satellite record from Landsat, Stanford environmental scientist Jeff Ho and colleagues examined 71 lakes in 33 countries on six continents. They focused on summertime conditions in large lakes (greater than 100 square kilometers/40 square miles) with different physical settings, latitudes, and levels of human impact.

Wastewater treatment changes nutrient balance in lakes - can lead to growth of poisonous algae

A vast number of new #wastewater treatment plants in developing countries has led to an imbalance in nutrients. The result could be excessive growth of potentially poisonous algae. As one of UN’s 17 sustainable development goals, clean water and sanitation receives a lot of attention. In order to reach this comprehensive goal, efficient municipal wastewater management plays a major role. Most human activities produce wastewater – and the annual production of municipal wastewater worldwide now exceeds the amount of water released by the enormous Amazon river to the Atlantic Ocean in roughly 12 days. “The volume of wastewater is continuing to grow with urbanization and the associated population increase. Increasing wastewater production, together with inadequate collection and treatment facilities, have led to negative impacts on water quality”, NIVA researcher Yan Lin said.

https://www.pnas.org/content/117/21/11566