Heavy rain proliferates toxic algae; threatens Lake Erie

A combination of irresponsible farming practices, loss of wetlands and heavy rain is endangering the wildlife and water quality in Lake Erie. 

The National Wildlife Federation released a report Monday outlining how record-breaking rainfalls have exacerbated the growth of blue-green algae, which produces a toxin called microcystin. 

The toxin eats away oxygen in the water, and if concentrated enough, can kill wildlife and hurt Lake Erie's recreational fishing industry that brings in $1 billion every year. 

"Although they are not a new phenomenon in Lake Erie, we are now noticing a striking relationship between large rain events and the size of HABs (harmful algal blooms)," the report reads. 

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Blue-green algae, along with other types of algae, are generated when phosphates, an inorganic chemical found in fertilizer and farm manure, are deposited into a body of water.  When rainwater floods through fertilized farmland, it sweeps the fertilizer into rivers or tributaries and generates more blue-green algae in Lake Erie. 

Melinda Koslow, regional program manager for the National Wildlife Federation and author of the report, said heavy rain, little wind and high temperatures in 2011 enabled the largest harmful algal bloom seen in Lake Erie. 

"The algae was so massive it could be seen from outer space," Koslow said. 

The blue-green algae hit Lake Erie's western and central basin the hardest, from Detroit to Cleveland. 

The Maumee River, stretching from Toledo to Fort Wayne, Ind., was, and still is, the largest contributor to Lake Erie's phosphate spillage. 

Peter Richards, a senior research scientist for the National Center for Water Quality Research at Heidelberg University, said the area surrounding the Maumee River is filled with farms near watershed tributaries.  He said the area also lacks wetlands to absorb rainwater runoff and the nutrients and minerals it carries. 

"We only have 5 percent of the wetlands that we used to have," Koslow said, referring to Lake Erie's coastal wetlands between pre-settlement times and 2009.  But she added that conservation groups are turning that percentile around. 

Don Scavia, director of the Graham Environmental Sustainability Institute at the University of Michigan, said rainwater overflow will often carry fertilizer and manure into the Sandusky and Cuyahoga River watersheds as well. 

"When the western basin has a high concentration of blue-green algae, you are guaranteed the central basin will have a big problem as well," Scavia said. 

In her report, Koslow said the key to solving this problem is careful timing of when farmers fertilize their soil.  Koslow said global warming is replacing moderate rainfalls with more extreme ones and said farmers should avoid fertilizing when weather forecasts call for them.  She also said it is unwise to fertilize soil when it is still frozen with little or no vegetation to absorb water and its nutrients. 

Another solution is for farmers to plant cover crops to absorb rainwater overflow, Koslow said in her report. 

No state or federal law mandates farmers to adopt any of these practices.  Scavia said Congress must include a conservation compliance rule in its crop insurance or crop subsidy program to ensure that farmers are doing all they can to reduce phosphates from spilling into Lake Erie when farmlands are flooded. 

"We are not pointing at farmers," Scavia said. " We're pointing at farm policies."