Microcystin Data

Weekly microcystin toxin report

Summer 2025 Results

If you already signed up for our microcystin toxin update emails, thank you! We’ll send reports to your inbox May-August. If you haven’t, what are you waiting for? They will remind you to check this page to see which lakes have microcystin detected, and at what levels.

Supported by the K21 Health Foundation, we sample 16 lakes and seven public beaches every week from June-August, and 14 streams biweekly year-round. Visit these excellent and educational resources to learn more about blue-green algae:

WEEK 7 RESULTS: JULY 4

IDEM’s safety threshold is 8.0 ppb for humans and 0.8 ppb for pets.

ND – None Detected

– – –  Data unavailable for this sampling week 

LakesConcentration (ppb)
Beaver Dam Lake0.692
Yellow Creek Lake0.672
Silver Lake4.618
Winona Lake0.236
Center Lake0.196
Pike Lake0.263
Big Chapman Lake0.596
Big Barbee Lake0.236
Webster Lake0.180
Lake Tippecanoe0.244
James Lake0.222
Oswego Lake0.197
Dewart Lake0.373
Waubee Lake3.146
Lake Wawasee*0.981
Syracuse Lake0.296

*See spatial variability results below.

BeachConcentration (ppb)
Center Lake BeachND
Pike Lake Beach0.174
Syracuse Lake Beach - Community CenterND
Syracuse Lake Beach - Hoy0.171
Waubee Lake Beach4.719
Webster Lake Beach0.541
Winona Lake BeachND

Additional sampling on Lake Wawasee

Thanks to the support of two generous Lake Wawasee families, the Lilly Center samples seven additional sites on Lake Wawasee during the summer of 2024. All water samples from these sites were tested for microcystin.

IDEM’s safety threshold is 8.0 ppb for humans and 0.8 ppb for pets.

ND – None Detected

– – –  Data unavailable for this sampling week

LetterNameConcentration
ADeepest Point0.981
BNorth Shore0.821
CConklin Bay0.344
DSouth Shore1.046
ESandbar1.008
FJohnson Bay1.171
GJarrett's Bay1.765
HCrow Bay2.308

What's next?

Every October, we publish Beneath the Surface, a report on our summer research as compared to the two previous years.

The 2024 edition includes a spread dedicated to blue-green algae (and microcystin) analysis! If you’re curious about what we learned over the course of the summer, make sure to grab a digital copy.

Why & how the Lilly Center samples for microcystin

From June-August, the Lilly Center collects water samples from open water on Kosciusko County’s 12 all-sport lakes and Center, Pike, Waubee, and Silver lakes, along with public swimming beaches at these lakes:

  • Center
  • Pike
  • Syracuse
  • Waubee
  • Webster
  • Winona

Samples are processed and analyzed for microcystin, a toxin produced by blue-green algae. If ingested or left on the skin for too long, microcystin can cause health problems for people and pets. It’s especially dangerous for animals, like dogs.

Toxin results are updated on this page every week during the summer. To learn more about microcystin and pet and human health, visit our blue-green algae research hub!

As a general guideline, don’t recreate in water that has a blue-green algae bloom! Blooms often look like a green paint slick on the surface or a pea-soup appearance. If you see a bloom (or aren’t sure if it’s a bloom) email us the date, time, location and a picture and a team member will follow up with you.

Collaboration with IDEM

Lilly Center algae sampling and analysis are coordinated with the Indiana Department of Environmental Management (IDEM) to ensure statewide data comparison and accuracy.

Visit IDEM's website