Study Makes Dire Prediction of Water-Fouling Algae Growth In
Block News Alliance
17 December 2015
By Tom Henry
Lake Erie appears unlikely to avoid massive algal blooms over the
next several decades because of how climate change “supercharges”
it like steroids, according to a new report Wednesday.
A pair of scientists presented that prediction in San Francisco at
the American Geophysical Union’s annual conference.
Under at least one climate model, Lake Erie’s number of severe
blooms “will likely double over the next 100 years,” said a
statement released by Ohio State University in conjunction with
The presentation by Noel Aloysius, a postdoctoral researcher in
OSU’s aquatic ecology laboratory, and Hans Paerl, a distinguished
professor at the University of North Carolina-Chapel Hill, hit on
familiar calls for tighter controls on farm fertilizers and other
forms of nutrient runoff, but also underscored the complexity of
the problem as Earth’s climate continues to warm.
The pair are at the midpoint of a two-year study, the first to
combine global climate change models with a watershed model. Their
focus has been on western Lake Erie, especially the Maumee River
They have used the most recent data from the Nobel-winning
Intergovernmental Panel on Climate Change. NOAA oceanographer Rick
Stumpf, who’s in charge of that agency’s annual forecasting for
Lake Erie, has led the study’s bloom-prediction model.
One of their take-home messages, Mr. Aloysius said, is that
policymakers need to include climate-change predictions more in
planning because they can no longer rely on historical trends.
“Climate change causes a synergistic effect,” Mr. Paerl said,
explaining that Lake Erie’s most troublesome algae, which is
actually a form of cyanobacteria called microcystis, thrives in
That type of algae is 3.5 billion years old, one of the oldest
living organisms on Earth. But climate change and poor land use
have helped it grow across the world, from the Arctic Circle to
South America, during the past 20 years.
Warmer temperatures “essentially play in the playbook of these
bacteria,” Mr. Paerl said. “They’ve seen it all. It can get warmer
and they’ll like it even more.”
Mr. Paerl, who has made more than a dozen research trips to China
lasting a month or longer, made several comparisons between Lake
Erie and China’s third-largest lake, Lake Taihu, a source of
drinking water for 10 million people.
Lake Taihu is five times smaller than Lake Erie and nine times
shallower, making it more susceptible to algae.
But it is seen as “a great test case for algae problems that the
United States will likely experience in decades to come,”
according to OSU’s statement.
Lake Taihu had much shorter seasonal blooms like Lake Erie several
years ago. In recent years, though, its blooms have lasted nine
months of the year.
In May 2007, in China’s Jiangsu province near the city of Wuxi, a
massive bloom of toxin-producing microcystis made drinking water
unsafe for 2 million people for more than a week.
The situation there was similar to what happened in western Lake
Erie in 2014, when a highly toxic bloom of microcystis made tap
water unsafe the first weekend of August for the Toledo metro
region’s nearly 500,000 customers.
“It’s exactly the same genus we see in Lake Erie,” Mr. Paerl said
of Lake Taihu.
Jay Martin, an OSU ecological engineering professor, agreed in an
OSU release that government agencies need to do more than look at
historical records when setting guidelines for nutrient
He and others said the goal of reducing nutrients into western
Lake Erie by 40 percent by 2025 may not be enough.
“Right now, we can only make recommendations based on the past,
but the climate is not a constant. We need to look to climate
models of the future to protect water quality in Lake Erie and
around the world,” Mr. Martin said. “Maybe 40 percent is not
enough of a reduction.”
The reduction targets are based around the most common nutrient,
phosphorus. The amount of phosphorus in the water column readily
available to algae dictates how large blooms will be.
But Mr. Paerl said more focus needs to be made on nitrogen,
another common nutrient, because the amount of it often dictates
how toxic the blooms are. Nitrogen, unlike phosphorus, is
dispersed in both water and air. It is airborne in coal-fired
power plant emissions and settles on the water.
The Block News Alliance consists of the Pittsburgh
Post-Gazette and The Blade of Toledo, Ohio. Tom
Henry is a reporter for The Blade.