The yearly outbreak of harmful algae on our shores went from unexpected a few years ago to a way of life in northwest Ohio.

TOLEDO, OH (WTOL) - The yearly outbreak of harmful algae on our shores went from unexpected a few years ago to a way of life in northwest Ohio.

It comes from us: Runoff from sewers, factory farms, crop fields, and our septic systems. The Maumee River watershed is the primary contributor to these blooms.

"This is the largest loader of Phosphorous. No tributary in the Great Lakes puts more phosphorous than the Maumee River," Dr. Jeff Reutter, a special advisor to the Ohio State Sea Grant said.

Too much phosphorous entering Lake Erie in the 60's and 70's was a problem too. At one time the lake was declared "dead."

But it was brought back. Agreements between the US and Canada were developed and phosphorous was cut by 60-percent. That solution worked for only a while.

"We focused on a dozen sewage treatment plants, blooms went away the lake responded and we became the walleye capital of the world," Dr. Reutter said. "We're fighting or working with the same issues as we did the 70's but I would say we have a bigger challenge because we have to work with 15,000 farmers instead of 15 sewage treatment plant."

But why are these blooms coming back when total nutrient loads are still within the guidelines set out last century?

Research shows a specific type of phosphorous, 'Dissolved Reactive Phosphorous,' is increasing.

It's found to be largely coming from rural sources, like agriculture. The leading work to detect these nutrients in our waterways is done in Tiffin at the National Center for Water Quality Research.

"Dissolved Phosphorous is a highly bioavailable form of phosphorous," Dr. Laura Johnson at the National Center for Water Quality Research said. "That's what we say when basically it's easily used by algae."

The percentage of Dissolved Phosphorous continues to increase, despite initial steps being made to slow runoff from cities and farms.

"You have to remember, it took us a number of years to get us where we are," Dr. Johnson explained. "It's going to take us some time to see these improvements. Nothing is just going to happen overnight, even if we do all the practices tomorrow."

Despite warnings, images of green water on our river or views from outer space showing a quarter of the lake covered in an algae bloom, some still ask: What's the big deal?

We know the toxins can render our water undrinkable. But the effects of a massive blooms year after year go further.

Tourism in the areas affected by the lake is $14 billion industry that entire towns have the economy based on.

Beyond that, left unchecked, these blooms could continue to grow to a point where they kill the lake.

"As those move east, they actually die and sink to the bottom. And when they are out near the central basin near Cleveland and die they start decomposing, suck oxygen out of the water," Dr. Chris Winslow, director of Ohio Sea Grant said.

If runoff can be reduced by 40 percent, the goal set for 2025, experts agree that blooms will return to a size in balance with the lakes ecosystem.