Moderate levels of algae blooms expected in Lake Erie this summer, but scientist still concerned

All signs are pointing to moderate or less than moderate levels of algae in Western Lake Erie this summer — but the situation is still "not good," according to a scientist with the International Joint Commission.

Rajesh Bejankiwar cited the spring data and scientists at the U.S. National Oceanic and Atmospheric Administration (NOAA) and the University of Michigan.

"I think we'll see very similar to what we experienced last year [in] 2023," Bejankiwar told CBC Radio's Windsor Morning host Amy Dodge.

According to Bejankiwar, Lake Erie has had an "algae issue" for a number of years.

He said "extreme levels of algae blooms" in the early 60s led to Lake Erie being declared "dead" because of hypoxia, which refers to a lack of oxygen in a body of water. Benjankiwar said this was due to the algae blooms and killed a massive number of fish.

However, Bejankiwar said different levels of government took action and Lake Erie recovered. It's since become one of the most productive lakes in terms of fisheries and recreation, and is a safe water source for millions of people.

Algae blooms important for lakes, ecosystem

While algae blooms can sometimes be harmful, Bejankiwar said they are also "really important for the lakes and ecosystems.

"They are actually [the] main building blocks. They are very important, but when they are in excess, they cause problems and that's why it's [a] concern."

Rajesh Bejankiwar says this year's algae bloom is forecast to be 'similar to what we experienced last year [in] 2023.' (Amy Dodge/CBC)

"[The] Toledo water system was closed [in 2014] and people had to start drinking bottled water. They couldn't bathe, there was an emergency declared. So, that's the main concern. It has impacts on other resources too — fishing, drinking water, people's recreation [and] property values" he added.

Climate change 'multiplying the impacts'

Bejankiwar said while it's been almost 20 years since the region has seen really severe algae blooms, things are still not great.

"It's not good. We have been seeing, continuously every summer, it's becoming unfortunately normal, but it's not normal," the scientist said.

"Given the situation of climate change impacts [and] the role of invasive species, I think that's multiplying the impacts and I think we need to change our direction in terms of taking actions."

Bejankiwar said while governments are making an effort and there is funding available, most of the actions being taken are voluntary.

"The regulation part is missing on many levels," he said.

NOAA's Lake Erie harmful algal bloom forecast

According to NOAA, this year's bloom for Western Lake Erie is expected to measure 5 on the severity index, with a potential range of 4.5 to 6 — similar to last year's bloom, which had a severity index of 5.3.

NOAA says moderate blooms have an index of 3 to 5, while an index above 5 indicates more severe, harmful algal blooms (HABs).

Blooms over 7.5 are particularly severe, with extensive scum formation and coverage affecting the lake. The largest HABs in Lake Erie occurred in 2011 with a severity index of 10, and 2015, with a severity index of 10.5, NOAA says.

The HAB severity index is based on the bloom's biomass (the amount of algae) during the peak 30 days of the bloom.

Bloom severity forecast compared to previous years. The wide red bar is the likely range of severity based on the different models used and reflect uncertainty in the July total bioavailable phosphorus (TBP) load. A severity below 3 is the goal of the Great Lakes Water Quality Agreement (GLWQA). (NOAA NCCOS)

In 2016 the U.S. and Canadian governments reached a deal to stop phosphorus runoff from farms and other sources ending up in Lake Erie.

The deal called for a 40 per cent reduction of phosphorus for the lake's central and Western sections, a target previously endorsed by Ohio, Michigan and Ontario. Those areas were hardest hit by massive algae blooms in previous years.

Both nations agreed to develop plans for achieving the reductions within two years.

Scientists say fertilizers and livestock manure from the region's farms are the primary generators of the type of phosphorus that feed harmful algae, although sewage from urban treatment plants and failed septic tanks also contribute. Although essential for aquatic food chains, algae can grow out of control when waters contain excess amounts of nutrients, including phosphorus.