Toxic algae is likely to get worse in Lake Erie. Here’s how to fix it
A new International Joint Commission report calls for the curtailing of fertilizer use.
/ NOAA Centers for Coastal Ocean Science
This photo from October 2011 shows the large cyanobacteria bloom in Lake Erie.
Around Lake Erie, cottagers, beach-goers, boaters and businesses would like to forget the summer of 2011.
That was when
blue-green toxic algae invaded the lake with the largest bloom ever
recorded, covering as much as one-sixth of the surface. It extended from
Toledo, Ohio, to beyond Cleveland and along its Ontario shore. It
closed down beaches and slowed boats.
It was a sea of smelly green.
Scientists with the
International Joint Commission’s Lake Erie Ecosystem Priority (LEEP) say
in a report released Thursday that “dissolved reactive phosphorus,” a
form of phosphorus primarily from agriculture practices, is the major
cause of renewed algae blooms.
Sewage plants
“contribute some phosphorus” to the lake, as they have for decades, the
report says but agricultural practices are the main culprit.
“There are many steps that need to be taken to save (Lake Erie)”, said Raj Bejankiwar, a scientist with the IJC. “The sooner it starts, the better.”
Phosphorus is used as fertilizer. It is also present in manure and waste products from agribusiness operations such as pig farms and greenhouses. Algae blooms are caused mostly by phosphorus runoffs, which happen during spring snowmelt and intense storms when significant amounts of phosphorus can flow into the lake.
(The blue-green algae thrive on light — Lake Erie is the shallowest of the Great Lakes and so more vulnerable.)
One of the report’s main recommendations is that Michigan and Ohio should declare the lake’s watersheds as impaired water.
That would enable the
U.S.’s Environmental Protection Agency to “assign certain loads to farms
and they will not be able to put more phosphorus,” said Bejankiwar.
The report is also asking all jurisdictions around Lake Erie to ban the application of fertilizers and manure on frozen ground.
“It is a farming
practice,” said Bejankiwar. “Farmers apply manure on frozen ground
between November and January. When snow melts, phosphorus is washed
away. We are asking it be stopped because it has been proven to be of no
use.”
The IJC is also asking both governments to ban or reduce application lawn fertilizers, he said.
Algae blooms are not
new to Lake Erie. Parts of the lake were declared biologically dead
because of algae infestation in the late 1960s. Then, U.S. and Canada
signed the Great Lakes Water Quality Agreement in 1972, investing
billions of dollars to reduce phosphorus flowing into the lakes.
The two governments got rid of phosphorus in detergents, improved sewage treatment plants and changed farming practices.
Lake Erie recovered. But not for long. Algae blooms have been back since 2000 but the 2011 was the worst year.
Climate change has
added a complex layer to the problem: Lake Erie’s waters are warmer than
before, and rain showers are more intense and that causes more
phosphorus runoff, John Nevin, who also works with IJC’s Lake Erie
Ecosystem Priority, told the Star last year.
A rainy spring isn’t something we can control, said Bejankiwar.
“What we can do is
restrict the amount of phosphorus that flows into the lake,” he said.
“The problem will only get worse otherwise.”
