Robotic laboratories on the bottom of Lake Erie have revealed that the muddy sediments there release nearly as much of the nutrient phosphorus into the surrounding waters as enters the lake’s central basin each year from rivers and their tributaries.
Robotic laboratories on the bottom of Lake Erie have revealed that the muddy sediments there release nearly as much of the nutrient phosphorus into the surrounding waters as enters the lake’s central basin each year from rivers and their tributaries.
Excessive phosphorus, largely from agricultural sources, contributes to the annual summer cyanobacteria bloom that plagues Lake Erie’s western basin and the central basin’s annual “dead zone,” an oxygen-starved region that blankets several thousand square miles of lake bottom and that reduces habitat for fish and other organisms.
The release of phosphorus from Lake Erie sediments during periods of low oxygen—a phenomenon known as self-fertilization or internal loading—has been acknowledged since the 1970s. But the new University of Michigan-led study marks the first time the process has been monitored step by step for an entire season using lake-bottom sensors.
The authors of the new study, published online Feb. 18 in the journal Environmental Science & Technology Water, say self-fertilization is likely increasing the severity of Lake Erie’s central-basin dead zone and could make it harder to control in the future, as the climate continues to warm.
Read more at University of Michigan
Photo Credit: loganwengerphotos via Pixabay
