The algal bloom reported May 19 on Grand Lake St. Marys is no cause for panic, says Lake Improvement Association President Tim Lovett. Recent heavy rains coupled with the fact that the first major action to clean the lake water won’t be initiated until June 1 means the biomass load and resulting algal bloom were expected.

“It’s important to understand that while we have a multi-tiered Action Plan in place, to date very little has actually been done to clean the lake water. The alum treatment scheduled for June 1 will be our first major attempt to neutralize the phosphorus in the lake, and we’re hopeful it will have a significant impact on eliminating the current algal bloom and reducing the likelihood for algal blooms this summer,” said Lovett. “There is no short-term solution to restoring Grand Lake St. Marys to a healthy environment for recreation, wildlife, and business; but we know if we stay the course and follow the Action Plan outlined by solid scientific research, Grand Lake St. Marys will once again be Ohio’s greatest natural resource.”

Last year Grand Lake St. Marys suffered toxic algal blooms that caused the state to restrict recreational activities, and since major political, legislative, community and volunteer support efforts have raised funds that will be used to clean the lake. This year’s heavy rainfall created heavy runoff, which brought heavy phosphorus loads from the watershed into Grand Lake St. Marys. Coupled with the shallow nature of the lake and a rise in temperature, it created a “perfect storm” for algal blooms to surface.

“It might get worse before it gets better, but that’s no cause for panic. It’s science,” said Lovett. “When you know what to expect, and you know what causes the problem, you can figure out how to solve it. That’s what the Action Plan is for, and if it is followed we are confident we will, in time, solve Grand Lake St. Marys’ problems. What we need now, more than anything, is continued support from the Grand Lake St. Marys community and our legislators so we can continue to move toward a future of fun and prosperity for all of the lake’s citizens and shareholders.”

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The original press release from the Ohio Department of Natural Resources regarding the May 19 algal bloom on Grand Lake St. Marys follows:

“Visitors to Park Beaches at Grand Lake St. Marys Urged to Exercise Caution

COLUMBUS, OH — Recreational users of the three public beaches at Grand Lake St. Marys State Park are advised against swimming and wading, water should not be swallowed, and surface scum should be avoided, according to the Ohio departments of Environmental Protection, Natural Resources, and Health. Advisories will be erected at West, East, and Camp beaches which are located at the eastern end of the lake.

The State is recommending that visitors exercise caution because an algal bloom has been indentified at Grand Lake St. Marys. Water samples taken earlier this week at the three beaches by the Ohio EPA indicated that Planktothrix was the dominant cyanobacteria in the water. The bloom is not confined to the beaches, but is visible over most of the lake. This type of bloom holds the potential for producing algal toxins, including mycrocystin, such as those experienced at the lake in recent years.

Algal blooms can produce neurotoxins (which affect the nervous system) and hepatotoxins (which affect the liver). The toxins can potentially impact the health of people and animals that come into contact with water where algal toxins are present.

Testing is ongoing and  the State of Ohio has chosen to post advisories in order to assure that lake-goers are aware of the levels of risk that exist, and the steps they can take to minimize those risks. For updated information, visit the Ohio EPA’s Web site at

The State of Ohio remains committed to working with regional partners on improving the water quality of the lake. Efforts by the state include:

  • Alum testing demonstrations earlier this spring
  • Addition of a third dredge and a longer dredging season
  • Rough fish removal
  • Water quality testing
  • Funding for in-stream treatment trains

Nearly 5,000 acres of the central lake area will receive a concentrated dose of aluminum sulfate beginning the first week of June.”