Remember back in 2011 when Lake Erie turned into a stinky sea of green and brown?
Well, scientists don’t expect it to turn back to “normal” any time soon. Turns out that fertilizer runoff, a lot of rain and snow, and unusually warm weather combined to create a perfect stew of algae aggravation.
In a report for the National Science Foundation, NSF program director Bruce Hamilton said that “The factors that led to this explosion of algal blooms are all related to humans and our interaction with the environment.”
A write-up on the NSF’s website notes that freshwater algal blooms may result when high amounts of phosphorus and nitrogen are added to the water, usually as runoff from fertilizer. These excess nutrients encourage unusual growth of algae and aquatic plants. When the plants and algae die, decomposers in the water that feed on them use up oxygen, which can drop to levels too low for aquatic life to thrive.
In other words, polluted runoff — something we’ve written about before — is having a profound effect
on the quality of the lake water. According to the report, researchers found that “three agriculture management practices in the area can lead to increased nutrient runoff: autumn fertilization, broadcast fertilization (uniform distribution of fertilizer over the whole cropped field), and reduced tillage.”
And the only way to clear up the water is to change the way we fertilize our crops and lawns and deal with polluted runoff. One important step is to establish a buffer zone.
In the write-up on the NSF’s website, Anna Michalak, the paper’s lead author, concurs. “The ‘perfect storm’ of weather events and agricultural practices that occurred in 2011 is unfortunately consistent with ongoing trends,” she says. Michalak, who is a scientist at the Carnegie Institution for Science’s Department of Global Ecology at Stanford University, says more “huge algal blooms can be expected in the future, unless a scientifically-guided management plan is implemented for the region.”
The Lake Erie algae blooms are just one example of our impact on the Earth’s water. If we don’t clean up our act, clean water will be a thing of the past.