ANN ARBORThe largest harmful algae bloom in Lake Erie's recorded history was likely caused by the confluence of changing farming practices and weather conditions that are expected to become more common in the future due to climate change.
Rather than an isolated, one-time occurrence, Lake Erie's monumental 2011 algae bloom was more likely a harbinger of things to come, according to University of Michigan researchers and colleagues from eight other institutions.
The interdisciplinary team explored factors that may have contributed to the event and analyzed the likelihood of future massive blooms in the lake.
"Intense spring rainstorms were a major contributing factor, and such storms are part of a long-term trend for this region that is projected to get worse in the future due to climate change," said aquatic ecologist Donald Scavia, director of U-M's Graham Sustainability Institute. "On top of that we have agricultural practices that provide the key nutrients that fuel large-scale blooms."
A paper summarizing the team's findings is scheduled for online publication April 1 in the journal Proceedings of the National Academy of Sciences.
The first author of the paper is former U-M researcher Anna Michalak, now at the Carnegie Institution for Science. Eighteen U-M co-authors from various departments and schools contributed to the study, which looked at land use, agricultural practices, precipitation, temperature, wind, lake circulation and surface runoff.
"This event was caused by a complex combination of factors, and I think this paper really puts all the pieces together in a very clear and systematic way," said U-M atmospheric scientist Allison Steiner, one of the co-authors. "We tried to think about this problem in a much more cross-disciplinary way than I think other people have thought about it before."
The researchers found that a series of intense spring rainstorms and runoff events result
|Contact: Jim Erickson|
University of Michigan