I live in Ohio, do a lot of outdoor activities, I'm a frequent visitor to the lake.
Unfortunately, Lake Erie--like the other four Great Lakes--has been treated like a giant cesspool for the past 300 years. The result is now painfully obvious: fish and wildlife dramatically down, rampant algal blooms like the one causing this Toledo water disruption, even very high counts of E. coli and fecal coliform.
It's a friggin' mess.
In answer to your specific question: reverse osmosis will remove about 80% of blue-green algal toxins. But that possible remaining 20% is not good for you, and, the algal cells can actually damage the RO system.
Here's a link with some rather technical explanations, if you're interested: http://epa.ohio.gov/ddagw/HAB.aspx#114700-basics and then click the PDF link to the right: AWWA White Paper on Algal Toxin Treatment.